Fixing from review

Bumps golang from 1.18.3 to 1.18.4.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.dockerignore

@@ -0,0 +1 @@
+bin/*

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: mikefarah

.github/ISSUE_TEMPLATE/bug_report_v3.md

@@ -0,0 +1,51 @@
+---
+name: Bug report - V3
+about: Create a report to help us improve
+title: ''
+labels: bug, v3
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+Note that any how to questions should be posted in the discussion board and not raised as an issue.
+
+Version of yq: 3.X.X
+Operating system: mac/linux/windows/....
+Installed via: docker/binary release/homebrew/snap/...
+
+**Input Yaml**
+Concise yaml document(s) (as simple as possible to show the bug, please keep it to 10 lines or less)
+data1.yml:
+```yaml
+this: should really work
+```
+
+data2.yml:
+```yaml
+but: it strangely didn't
+```
+
+**Command**
+The command you ran:
+```
+yq merge data1.yml data2.yml
+```
+
+**Actual behavior**
+
+```yaml
+cat: meow
+```
+
+**Expected behavior**
+
+```yaml
+this: should really work
+but: it strangely didn't
+```
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/bug_report_v4.md

@@ -0,0 +1,51 @@
+---
+name: Bug report - V4
+about: Create a report to help us improve
+title: ''
+labels: bug, v4
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+Note that any how to questions should be posted in the discussion board and not raised as an issue.
+
+Version of yq: 4.X.X
+Operating system: mac/linux/windows/....
+Installed via: docker/binary release/homebrew/snap/...
+
+**Input Yaml**
+Concise yaml document(s) (as simple as possible to show the bug, please keep it to 10 lines or less)
+data1.yml:
+```yaml
+this: should really work
+```
+
+data2.yml:
+```yaml
+but: it strangely didn't
+```
+
+**Command**
+The command you ran:
+```
+yq eval-all 'select(fileIndex==0) | .a.b.c' data1.yml data2.yml
+```
+
+**Actual behavior**
+
+```yaml
+cat: meow
+```
+
+**Expected behavior**
+
+```yaml
+this: should really work
+but: it strangely didn't
+```
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,42 @@
+---
+name: Feature request - V4
+about: Suggest an idea for this project
+title: ''
+labels: enhancement, v4
+assignees: ''
+
+---
+
+**Please describe your feature request.**
+A clear and concise description of what the request is and what it would solve. 
+Eg. I wish I could use yq to [...]
+
+Note:
+- how to questions should be posted in the discussion board and not raised as an issue.
+- V3 will no longer have any enhancements.
+
+**Describe the solution you'd like**
+If we have data1.yml like:
+(please keep to around 10 lines )
+
+```yaml
+country: Australia
+```
+
+And we run a command:
+
+```bash
+yq 'predictWeatherOf(.country)'
+```
+
+it could output
+
+```yaml
+temp: 32
+```
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/dependabot.yml

@@ -0,0 +1,22 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: docker
+    directory: /
+    schedule:
+      day: thursday
+      interval: weekly
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      day: thursday
+      interval: weekly
+  - package-ecosystem: gomod
+    directory: /
+    schedule:
+      day: thursday
+      interval: weekly

.github/workflows/codeql.yml

@@ -0,0 +1,70 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '24 3 * * 1'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
+        # Learn more about CodeQL language support at https://aka.ms/codeql-docs/language-support
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v3
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v2
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v2
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v2

.github/workflows/docker-release.yml

@@ -0,0 +1,62 @@
+name: Release Docker
+
+on:
+  release:
+    types: [released]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  publishDocker:
+    environment: dockerhub
+    env:
+      IMAGE_NAME: mikefarah/yq
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: all
+
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v2
+        with:
+          version: latest
+
+      - name: Available platforms
+        run: echo ${{ steps.buildx.outputs.platforms }} && docker version
+
+      - name: Build and push image
+        run: |
+          echo "GithubRef: ${GITHUB_REF}"
+          VERSION=${GITHUB_REF##*/}
+          echo "VERSION: ${VERSION}"
+          IMAGE_VERSION=${VERSION:1}
+          echo "IMAGE_VERSION: ${IMAGE_VERSION}"
+
+          PLATFORMS="linux/amd64,linux/ppc64le,linux/arm64"
+
+          echo "Building and pushing version ${IMAGE_VERSION} of image ${IMAGE_NAME}"
+          echo '${{ secrets.DOCKER_PASSWORD }}' | docker login -u '${{ secrets.DOCKER_USERNAME }}' --password-stdin
+          docker buildx build \
+            --label "org.opencontainers.image.authors=https://github.com/mikefarah/yq/graphs/contributors" \
+            --label "org.opencontainers.image.created=$(date --rfc-3339=seconds)" \
+            --label "org.opencontainers.image.description=yq is a portable command-line YAML processor" \
+            --label "org.opencontainers.image.documentation=https://mikefarah.gitbook.io/yq/" \
+            --label "org.opencontainers.image.licenses=MIT" \
+            --label "org.opencontainers.image.revision=$(git rev-parse HEAD)" \
+            --label "org.opencontainers.image.source=https://github.com/mikefarah/yq" \
+            --label "org.opencontainers.image.title=yq" \
+            --label "org.opencontainers.image.url=https://mikefarah.gitbook.io/yq/" \
+            --label "org.opencontainers.image.version=${IMAGE_VERSION}" \
+            --platform "${PLATFORMS}" \
+            --pull \
+            --push \
+            -t "${IMAGE_NAME}:${IMAGE_VERSION}" \
+            -t "${IMAGE_NAME}:4" \
+            -t "${IMAGE_NAME}:latest" \
+            .

.github/workflows/go.yml

@@ -0,0 +1,35 @@
+name: Build
+on: [push, pull_request]
+permissions:
+  contents: read
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Set up Go 1.18
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.18
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
+
+    - name: Get dependencies
+      run: |
+        go get -v -t -d ./...
+        if [ -f Gopkg.toml ]; then
+            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+            dep ensure
+        fi
+
+    - name: Check the build
+      shell: bash -l {0}
+      run: |
+        export PATH=${PATH}:`go env GOPATH`/bin
+        scripts/devtools.sh
+        make local build

.github/workflows/release.yml

@@ -0,0 +1,53 @@
+name: Release YQ
+on:
+  push:
+    tags:
+      - 'v*'
+      - 'draft-*'
+
+jobs:
+  publishGitRelease:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v3
+        with:
+          go-version: '^1.18'
+      - name: Compile man page markup
+        id: gen-man-page-md
+        run: |
+          ./scripts/generate-man-page-md.sh
+          echo "::set-output name=man-page-md::man.md"
+
+      - name: Get the version
+        id: get_version
+        run: echo ::set-output name=VERSION::${GITHUB_REF##*/}
+
+      - name: Generate man page
+        uses: docker://pandoc/core:2.14.2
+        id: gen-man-page
+        with:
+          args: >-
+            --standalone
+            --to man
+            --variable=title:"YQ"
+            --variable=section:"1"
+            --variable=header:"yq (https://github.com/mikefarah/yq/) version ${{ steps.get_version.outputs.VERSION }}"
+            --variable=author:"Mike Farah"
+            --output=yq.1
+            ${{ steps.gen-man-page-md.outputs.man-page-md }}
+
+      - name: Cross compile
+        run: |
+          sudo apt-get install rhash -y
+          go install github.com/mitchellh/gox@v1.0.1
+          mkdir -p build
+          cp yq.1 build/yq.1
+          ./scripts/xcompile.sh
+
+      - name: Release
+        uses: softprops/action-gh-release@v1
+        with:
+          files: build/*
+          draft: true
+          fail_on_unmatched_files: true

.github/workflows/test-yq.yml

@@ -0,0 +1,22 @@
+name: Test Yq Action
+on: [push]
+permissions:
+  contents: read
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Get test
+        uses: mikefarah/yq@master
+        with:
+          cmd: yq eval '.a' examples/sample.yaml
+      - name: Write inplace test
+        id: lookupSdkVersion
+        uses: mikefarah/yq@master
+        with:
+          cmd: yq eval -i '.b.c = 5' examples/sample.yaml

.gitignore

@@ -6,7 +6,9 @@
 # Folders
 _obj
 _test
+bin
 build
+build-done
 .DS_Store
 
 # Architecture specific extensions/prefixes
@@ -20,8 +22,38 @@ _cgo_gotypes.go
 _cgo_export.*
 
 _testmain.go
-
+coverage.out
+coverage.html
 *.exe
 *.test
 *.prof
 yaml
+vendor/
+tmp/
+cover/
+yq
+
+# snapcraft
+parts/
+prime/
+.snapcraft/
+yq*.snap
+
+test.yml
+test*.yml
+test*.yaml
+0.yml
+1.yml
+2.yml
+
+
+# man page
+man.md
+yq.1
+
+# debian pkg
+_build
+debian/files
+
+# intellij
+/.idea

.golangci.yml

@@ -0,0 +1,40 @@
+run:
+  timeout: 5m
+linters:
+  enable:
+    - asciicheck
+    - depguard
+    - errorlint
+    - gci
+    - gochecknoinits
+    - gofmt
+    - goimports
+    - gosec
+    - megacheck
+    - misspell
+    - nakedret
+    - nolintlint
+    - predeclared
+    - revive
+    - unconvert
+    - unparam
+linters-settings:
+  depguard:
+    list-type: blacklist
+    include-go-root: true
+    packages:
+      - io/ioutil
+    packages-with-error-message:
+      - io/ioutil: "The 'io/ioutil' package is deprecated. Use corresponding 'os' or 'io' functions instead."
+issues:
+  exclude-rules:
+  - linters:
+    - gosec
+    text:  "Implicit memory aliasing in for loop."
+    path: _test\.go
+  - linters:
+    - revive
+    text: "unexported-return"
+  - linters:
+    - revive
+    text: "var-naming"

CODE_OF_CONDUCT.md

@@ -0,0 +1,76 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, sex characteristics, gender identity and expression,
+level of experience, education, socio-economic status, nationality, personal
+appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+ advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+ address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+ professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at mikefarah@gmail.com. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see
+https://www.contributor-covenant.org/faq

CONTRIBUTING.md

@@ -0,0 +1,40 @@
+# Development
+
+1. Install (golang)[https://golang.org/]
+1. Run  `scripts/devtools.sh` to install the required devtools
+2. Run `make [local] vendor` to install the vendor dependencies
+2. Run `make [local] test` to ensure you can run the existing tests
+3. Write unit tests - (see existing examples). Changes will not be accepted without corresponding unit tests.
+4. Make the code changes.
+5. `make [local] test` to lint code and run tests
+6. Profit! ok no profit, but raise a PR and get kudos :)
+
+
+# Documentation
+
+The documentation is a bit of a mixed bag (sorry in advanced, I do plan on simplifying it...) - with some parts automatically generated and stiched together and some statically defined.
+
+Documentation is written in markdown, and is published in the 'gitbook' branch.
+
+The various operator documentation (e.g. 'strings') are generated from the 'master' branch, and have a statically defined header (e.g. `pkg/yqlib/doc/operators/headers/add.md`) and the bulk of the docs are generated from the unit tests e.g. `pkg/yqlib/operator_add_test.go`.
+
+The pipeline will run the tests and automatically concatenate the files together, and put them under 
+`pkg/qylib/doc/add.md`. These files are checked in the master branch (and are copied to the gitbook branch as part of the release process).
+
+## How to contribute
+
+The first step is to find if what you want is automatically generated or not - start by looking in the master branch. 
+
+### Updating dynamic documentation from master
+- Search for the documentation you want to update. If you find matches in a `*_test.go` file - update that, as that will automatically update the matching `*.md` file 
+- Assuming you are updating a `*_test.go` file, once updated, run the test to regenerated the docs. E.g. for the 'Add' test generated docs, from the pkg/yqlib folder run:
+`go test -run TestAddOperatorScenarios` which will run that test defined in the `operator_add_test.go` file.
+- Ensure the tests still pass, and check the generated documentation have your update.
+- Note: If the documentation is only in a `headers/*.md` file, then just update that directly
+- Raise a PR to merge the changes into master!
+
+### Updating static documentation from the gitbook branch
+If you haven't found what you want to update in the master branch, then check the gitbook branch directly as there are a few pages in there that are not in master.
+
+- Update the `*.md` files
+- Raise a PR to merge the changes into gitbook.

Dockerfile

@@ -0,0 +1,28 @@
+FROM golang:1.18.4 as builder
+
+WORKDIR /go/src/mikefarah/yq
+
+COPY . .
+
+RUN CGO_ENABLED=0 go build .
+# RUN ./scripts/test.sh -- this too often times out in the github pipeline.
+RUN ./scripts/acceptance.sh
+
+# Choose alpine as a base image to make this useful for CI, as many
+# CI tools expect an interactive shell inside the container
+FROM alpine:3 as production
+LABEL maintainer="Mike Farah <mikefarah@users.noreply.github.com>"
+
+COPY --from=builder /go/src/mikefarah/yq/yq /usr/bin/yq
+
+WORKDIR /workdir
+
+RUN set -eux; \
+  addgroup -g 1000 yq; \
+  adduser -u 1000 -G yq -s /bin/sh -h /home/yq -D yq
+
+RUN chown -R yq:yq /workdir
+
+USER yq
+
+ENTRYPOINT ["/usr/bin/yq"]

Dockerfile.dev

@@ -0,0 +1,10 @@
+FROM golang:1.18.4
+
+COPY scripts/devtools.sh /opt/devtools.sh
+
+RUN set -e -x \
+    && /opt/devtools.sh
+ENV PATH=/go/bin:$PATH
+
+ENV CGO_ENABLED 0
+ENV GOPATH /go:/yq

LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2017 Mike Farah
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,119 @@
+MAKEFLAGS += --warn-undefined-variables
+SHELL := /bin/bash
+.SHELLFLAGS := -o pipefail -euc
+.DEFAULT_GOAL := install
+ENGINE := $(shell { command -v podman || command -v docker; } 2>/dev/null)
+
+include Makefile.variables
+
+.PHONY: help
+help:
+	@echo 'Management commands for cicdtest:'
+	@echo
+	@echo 'Usage:'
+	@echo '  ## Develop / Test Commands'
+	@echo '    make build           Build yq binary.'
+	@echo '    make install         Install yq.'
+	@echo '    make xcompile        Build cross-compiled binaries of yq.'
+	@echo '    make vendor          Install dependencies to vendor directory.'
+	@echo '    make format          Run code formatter.'
+	@echo '    make check           Run static code analysis (lint).'
+	@echo '    make secure          Run gosec.'
+	@echo '    make test            Run tests on project.'
+	@echo '    make cover           Run tests and capture code coverage metrics on project.'
+	@echo '    make clean           Clean the directory tree of produced artifacts.'
+	@echo
+	@echo '  ## Utility Commands'
+	@echo '    make setup           Configures Minishfit/Docker directory mounts.'
+	@echo
+
+
+.PHONY: clean
+clean:
+	@rm -rf bin build cover *.out
+
+## prefix before other make targets to run in your local dev environment
+local: | quiet
+	@$(eval ENGINERUN= )
+	@mkdir -p tmp
+	@touch tmp/dev_image_id
+quiet: # this is silly but shuts up 'Nothing to be done for `local`'
+	@:
+
+prepare: tmp/dev_image_id
+tmp/dev_image_id: Dockerfile.dev scripts/devtools.sh
+	@mkdir -p tmp
+	@${ENGINE} rmi -f ${DEV_IMAGE} > /dev/null 2>&1 || true
+	@${ENGINE} build -t ${DEV_IMAGE} -f Dockerfile.dev .
+	@${ENGINE} inspect -f "{{ .ID }}" ${DEV_IMAGE} > tmp/dev_image_id
+
+# ----------------------------------------------
+# build
+.PHONY: build
+build: build/dev
+
+.PHONY: build/dev
+build/dev: test *.go
+	@mkdir -p bin/
+	${ENGINERUN} go build --ldflags "$(LDFLAGS)"
+	${ENGINERUN} bash ./scripts/acceptance.sh
+
+## Compile the project for multiple OS and Architectures.
+xcompile: check
+	@rm -rf build/
+	@mkdir -p build
+	${ENGINERUN} bash ./scripts/xcompile.sh
+	@find build -type d -exec chmod 755 {} \; || :
+	@find build -type f -exec chmod 755 {} \; || :
+
+.PHONY: install
+install: build
+	${ENGINERUN} go install
+
+# Each of the fetch should be an entry within vendor.json; not currently included within project
+.PHONY: vendor
+vendor: tmp/dev_image_id
+	@mkdir -p vendor
+	${ENGINERUN} go mod vendor
+
+# ----------------------------------------------
+# develop and test
+
+.PHONY: format
+format: vendor
+	${ENGINERUN} bash ./scripts/format.sh
+
+
+.PHONY: secure
+secure: format
+	${ENGINERUN} bash ./scripts/secure.sh
+
+.PHONY: check
+check: secure
+	${ENGINERUN} bash ./scripts/check.sh
+
+
+
+.PHONY: test
+test: check
+	${ENGINERUN} bash ./scripts/test.sh
+
+.PHONY: cover
+cover: check
+	@rm -rf cover/
+	@mkdir -p cover
+	${ENGINERUN} bash ./scripts/coverage.sh
+	@find cover -type d -exec chmod 755 {} \; || :
+	@find cover -type f -exec chmod 644 {} \; || :
+
+
+.PHONY: release
+release: xcompile
+	${ENGINERUN} bash ./scripts/publish.sh
+
+# ----------------------------------------------
+# utilities
+
+.PHONY: setup
+setup:
+	@bash ./scripts/setup.sh

Makefile.variables

@@ -0,0 +1,38 @@
+export PROJECT = yq
+IMPORT_PATH := github.com/mikefarah/${PROJECT}
+
+export GIT_COMMIT = $(shell git rev-parse --short HEAD)
+export GIT_DIRTY = $(shell test -n "$$(git status --porcelain)" && echo "+CHANGES" || true)
+export GIT_DESCRIBE = $(shell git describe --tags --always)
+LDFLAGS :=
+LDFLAGS += -X main.GitCommit=${GIT_COMMIT}${GIT_DIRTY}
+LDFLAGS += -X main.GitDescribe=${GIT_DESCRIBE}
+
+GITHUB_TOKEN ?=
+
+# Windows environment?
+CYG_CHECK := $(shell hash cygpath 2>/dev/null && echo 1)
+ifeq ($(CYG_CHECK),1)
+	VBOX_CHECK := $(shell hash VBoxManage 2>/dev/null && echo 1)
+
+	# Docker Toolbox (pre-Windows 10)
+	ifeq ($(VBOX_CHECK),1)
+		ROOT := /${PROJECT}
+	else
+		# Docker Windows
+		ROOT := $(shell cygpath -m -a "$(shell pwd)")
+	endif
+else
+	# all non-windows environments
+	ROOT := $(shell pwd)
+endif
+
+DEV_IMAGE := ${PROJECT}_dev
+
+ENGINERUN := ${ENGINE} run --rm \
+	-e LDFLAGS="${LDFLAGS}" \
+	-e GITHUB_TOKEN="${GITHUB_TOKEN}" \
+	-v ${ROOT}/vendor:/go/src \
+	-v ${ROOT}:/${PROJECT}/src/${IMPORT_PATH} \
+	-w /${PROJECT}/src/${IMPORT_PATH} \
+	${DEV_IMAGE}

README.md

@@ -1,73 +1,352 @@
-# yaml
-yaml command line tool written in go
+# yq
 
-Allows you to read (and soon update) yaml files given a yaml path. All in a lovely dependency free binary!
+![Build](https://github.com/mikefarah/yq/workflows/Build/badge.svg)  ![Docker Pulls](https://img.shields.io/docker/pulls/mikefarah/yq.svg) ![Github Releases (by Release)](https://img.shields.io/github/downloads/mikefarah/yq/total.svg) ![Go Report](https://goreportcard.com/badge/github.com/mikefarah/yq) ![CodeQL](https://github.com/mikefarah/yq/workflows/CodeQL/badge.svg)
 
-[Download latest release](https://github.com/mikefarah/yaml/releases/latest)
 
-or alternatively install using go get:
-```
-go get github.com/mikefarah/yaml
-```
+a lightweight and portable command-line YAML, JSON and XML processor. `yq` uses [jq](https://github.com/stedolan/jq) like syntax but works with yaml files as well as json and xml. It doesn't yet support everything `jq` does - but it does support the most common operations and functions, and more is being added continuously.
 
-## Read examples
-```
-yaml <yaml file> <path>
-```
+yq is written in go - so you can download a dependency free binary for your platform and you are good to go! If you prefer there are a variety of package managers that can be used as well as Docker and Podman, all listed below.
 
-### Basic
-Given a sample.yaml file of:
-```yaml
-b:
-  c: 2
-```
-then
+## Notice for v4.x versions prior to 4.18.1
+Since 4.18.1, yq's 'eval/e' command is the _default_ command and no longer needs to be specified.
+
+Older versions will still need to specify 'eval/e'.
+
+Similarly, '-' is no longer required as a filename to read from STDIN (unless reading from one or more files).
+
+TLDR:
+
+Prior to 4.18.1 
 ```bash
-yaml sample.yaml b.c
+yq e '.cool' - < file.yaml
 ```
-will output the value of '2'.
 
-### Handling '.' in the yaml key
-Given a sample.yaml file of:
-```yaml
-b.x:
-  c: 2
-```
-then
+4.18+ 
 ```bash
-yaml sample.yaml \"b.x\".c
+yq '.cool' < file.yaml
 ```
-will output the value of '2'.
 
-### Arrays
-You can give an index to access a specific element:
-e.g.: given a sample file of
-```yaml
-b:
-  e:
-    - name: fred
-      value: 3
-    - name: sam
-      value: 4
-```
-then
-```
-yaml sample.yaml b.e[1].name
-```
-will output 'sam'
+When merging multiple files together, `eval-all/ea` is still required to tell `yq` to run the expression against all the document at once.
 
-### Updating yaml
-Given a sample.yaml file of:
-```yaml
-b:
-  c: 2
-```
-then
+## Quick Usage Guide
+
+Read a value:
 ```bash
-yaml w sample.yaml b.c 'cat'
+yq '.a.b[0].c' file.yaml
 ```
-will output:
-```yaml
-b:
-  c: cat
+
+Pipe from STDIN:
+```bash
+yq '.a.b[0].c' < file.yaml
 ```
+
+Update a yaml file, inplace
+```bash
+yq -i '.a.b[0].c = "cool"' file.yaml
+```
+
+Update using environment variables
+```bash
+NAME=mike yq -i '.a.b[0].c = strenv(NAME)' file.yaml
+```
+
+Merge multiple files
+```bash
+# note the use of `ea` to evaluate all the files at once
+# instead of in sequence
+yq ea '. as $item ireduce ({}; . * $item )' path/to/*.yml
+```
+
+Multiple updates to a yaml file
+```bash
+yq -i '
+  .a.b[0].c = "cool" |
+  .x.y.z = "foobar" |
+  .person.name = strenv(NAME)
+' file.yaml
+```
+
+Convert JSON to YAML
+```bash
+yq -P sample.json
+```
+
+See the [documentation](https://mikefarah.gitbook.io/yq/) for more examples.
+
+## Install
+
+### [Download the latest binary](https://github.com/mikefarah/yq/releases/latest)
+
+### wget
+Use wget to download the pre-compiled binaries:
+
+#### Compressed via tar.gz
+```bash
+wget https://github.com/mikefarah/yq/releases/download/${VERSION}/${BINARY}.tar.gz -O - |\
+  tar xz && mv ${BINARY} /usr/bin/yq
+```
+
+#### Plain binary
+
+```bash
+wget https://github.com/mikefarah/yq/releases/download/${VERSION}/${BINARY} -O /usr/bin/yq &&\
+    chmod +x /usr/bin/yq
+```
+
+For instance, VERSION=v4.2.0 and BINARY=yq_linux_amd64
+
+### MacOS / Linux via Homebrew:
+Using [Homebrew](https://brew.sh/)
+```
+brew install yq
+```
+
+### Linux via snap:
+```
+snap install yq
+```
+
+#### Snap notes
+`yq` installs with [_strict confinement_](https://docs.snapcraft.io/snap-confinement/6233) in snap, this means it doesn't have direct access to root files. To read root files you can:
+
+```
+sudo cat /etc/myfile | yq '.a.path'
+```
+
+And to write to a root file you can either use [sponge](https://linux.die.net/man/1/sponge):
+```
+sudo cat /etc/myfile | yq '.a.path = "value"' | sudo sponge /etc/myfile
+```
+or write to a temporary file:
+```
+sudo cat /etc/myfile | yq '.a.path = "value"' | sudo tee /etc/myfile.tmp
+sudo mv /etc/myfile.tmp /etc/myfile
+rm /etc/myfile.tmp
+```
+
+### Run with Docker or Podman
+#### Oneshot use:
+
+```bash
+docker run --rm -v "${PWD}":/workdir mikefarah/yq [command] [flags] [expression ]FILE...
+```
+
+Note that you can run `yq` in docker without network access and other privileges if you desire,
+namely `--security-opt=no-new-privileges --cap-drop all --network none`.
+
+```bash
+podman run --rm -v "${PWD}":/workdir mikefarah/yq [command] [flags] [expression ]FILE...
+```
+
+#### Pipe in via STDIN:
+
+You'll need to pass the `-i\--interactive` flag to docker:
+
+```bash
+docker run -i --rm mikefarah/yq '.this.thing' < myfile.yml
+```
+
+```bash
+podman run -i --rm mikefarah/yq '.this.thing' < myfile.yml
+```
+
+#### Run commands interactively:
+
+```bash
+docker run --rm -it -v "${PWD}":/workdir --entrypoint sh mikefarah/yq
+```
+
+```bash
+podman run --rm -it -v "${PWD}":/workdir --entrypoint sh mikefarah/yq
+```
+
+It can be useful to have a bash function to avoid typing the whole docker command:
+
+```bash
+yq() {
+  docker run --rm -i -v "${PWD}":/workdir mikefarah/yq "$@"
+}
+```
+
+```bash
+yq() {
+  podman run --rm -i -v "${PWD}":/workdir mikefarah/yq "$@"
+}
+```
+#### Running as root:
+
+`yq`'s container image no longer runs under root (https://github.com/mikefarah/yq/pull/860). If you'd like to install more things in the container image, or you're having permissions issues when attempting to read/write files you'll need to either:
+
+
+```
+docker run --user="root" -it --entrypoint sh mikefarah/yq
+```
+
+```
+podman run --user="root" -it --entrypoint sh mikefarah/yq
+```
+
+Or, in your Dockerfile:
+
+```
+FROM mikefarah/yq
+
+USER root
+RUN apk add --no-cache bash
+USER yq
+```
+
+#### Missing timezone data
+By default, the alpine image yq uses does not include timezone data. If you'd like to use the `tz` operator, you'll need to include this data:
+
+```
+FROM mikefarah/yq
+
+USER root
+RUN apk add --no-cache tzdata
+USER yq
+```
+
+### GitHub Action
+```
+  - name: Set foobar to cool
+    uses: mikefarah/yq@master
+    with:
+      cmd: yq -i '.foo.bar = "cool"' 'config.yml'
+```
+
+See https://mikefarah.gitbook.io/yq/usage/github-action for more.
+
+### Go Install:
+```
+go install github.com/mikefarah/yq/v4@latest
+```
+
+## Community Supported Installation methods
+As these are supported by the community :heart: - however, they may be out of date with the officially supported releases.
+
+# Webi
+
+```
+webi yq
+```
+
+See [webi](https://webinstall.dev/)
+Supported by @adithyasunil26 (https://github.com/webinstall/webi-installers/tree/master/yq)
+
+### Arch Linux
+
+```
+pacman -S go-yq
+```
+
+### Windows:
+[![Chocolatey](https://img.shields.io/chocolatey/v/yq.svg)](https://chocolatey.org/packages/yq)
+[![Chocolatey](https://img.shields.io/chocolatey/dt/yq.svg)](https://chocolatey.org/packages/yq)
+```
+choco install yq
+```
+Supported by @chillum (https://chocolatey.org/packages/yq)
+
+### Mac:
+Using [MacPorts](https://www.macports.org/)
+```
+sudo port selfupdate
+sudo port install yq
+```
+Supported by @herbygillot (https://ports.macports.org/maintainer/github/herbygillot)
+
+### Alpine Linux
+- Enable edge/community repo by adding ```$MIRROR/alpine/edge/community``` to ```/etc/apk/repositories```
+- Update database index with ```apk update```
+- Install yq with ```apk add yq```
+
+Supported by Tuan Hoang
+https://pkgs.alpinelinux.org/package/edge/community/x86/yq
+
+
+### On Ubuntu 16.04 or higher from Debian package:
+```sh
+sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys CC86BB64
+sudo add-apt-repository ppa:rmescandon/yq
+sudo apt update
+sudo apt install yq -y
+```
+Supported by @rmescandon (https://launchpad.net/~rmescandon/+archive/ubuntu/yq)
+
+## Features
+- [Detailed documentation with many examples](https://mikefarah.gitbook.io/yq/)
+- Written in portable go, so you can download a lovely dependency free binary
+- Uses similar syntax as `jq` but works with YAML, [JSON](https://mikefarah.gitbook.io/yq/usage/convert) and [XML](https://mikefarah.gitbook.io/yq/usage/xml) files
+- Fully supports multi document yaml files
+- Supports yaml [front matter](https://mikefarah.gitbook.io/yq/usage/front-matter) blocks (e.g. jekyll/assemble)
+- Colorized yaml output
+- [Date/Time manipulation and formatting with TZ](https://mikefarah.gitbook.io/yq/operators/datetime)
+- [Deeply data structures](https://mikefarah.gitbook.io/yq/operators/traverse-read)
+- [Sort keys](https://mikefarah.gitbook.io/yq/operators/sort-keys)
+- Manipulate yaml [comments](https://mikefarah.gitbook.io/yq/operators/comment-operators), [styling](https://mikefarah.gitbook.io/yq/operators/style), [tags](https://mikefarah.gitbook.io/yq/operators/tag) and [anchors and aliases](https://mikefarah.gitbook.io/yq/operators/anchor-and-alias-operators).
+- [Update inplace](https://mikefarah.gitbook.io/yq/v/v4.x/commands/evaluate#flags)
+- [Complex expressions to select and update](https://mikefarah.gitbook.io/yq/operators/select#select-and-update-matching-values-in-map)
+- Keeps yaml formatting and comments when updating (though there are issues with whitespace)
+- [Decode/Encode base64 data](https://mikefarah.gitbook.io/yq/operators/encode-decode)
+- [Load content from other files](https://mikefarah.gitbook.io/yq/operators/load)
+- [Convert to/from json](https://mikefarah.gitbook.io/yq/v/v4.x/usage/convert)
+- [Convert to/from xml](https://mikefarah.gitbook.io/yq/v/v4.x/usage/xml)
+- [Convert to/from properties](https://mikefarah.gitbook.io/yq/v/v4.x/usage/properties)
+- [Convert to csv/tsv](https://mikefarah.gitbook.io/yq/usage/csv-tsv)
+- [General shell completion scripts (bash/zsh/fish/powershell)](https://mikefarah.gitbook.io/yq/v/v4.x/commands/shell-completion)
+- [Reduce](https://mikefarah.gitbook.io/yq/operators/reduce) to merge multiple files or sum an array or other fancy things.
+- [Github Action](https://mikefarah.gitbook.io/yq/usage/github-action) to use in your automated pipeline (thanks @devorbitus)
+
+## [Usage](https://mikefarah.gitbook.io/yq/)
+
+Check out the [documentation](https://mikefarah.gitbook.io/yq/) for more detailed and advanced usage.
+
+```
+Usage:
+  yq [flags]
+  yq [command]
+
+Examples:
+
+# yq defaults to 'eval' command if no command is specified. See "yq eval --help" for more examples.
+yq '.stuff' < myfile.yml # outputs the data at the "stuff" node from "myfile.yml"
+
+yq -i '.stuff = "foo"' myfile.yml # update myfile.yml inplace
+
+
+Available Commands:
+  completion       Generate the autocompletion script for the specified shell
+  eval             (default) Apply the expression to each document in each yaml file in sequence
+  eval-all         Loads _all_ yaml documents of _all_ yaml files and runs expression once
+  help             Help about any command
+  shell-completion Generate completion script
+
+Flags:
+  -C, --colors                        force print with colors
+  -e, --exit-status                   set exit status if there are no matches or null or false is returned
+  -f, --front-matter string           (extract|process) first input as yaml front-matter. Extract will pull out the yaml content, process will run the expression against the yaml content, leaving the remaining data intact
+      --header-preprocess             Slurp any header comments and separators before processing expression. (default true)
+  -h, --help                          help for yq
+  -I, --indent int                    sets indent level for output (default 2)
+  -i, --inplace                       update the file inplace of first file given.
+  -p, --input-format string           [yaml|y|xml|x] parse format for input. Note that json is a subset of yaml. (default "yaml")
+  -M, --no-colors                     force print with no colors
+  -N, --no-doc                        Don't print document separators (---)
+  -n, --null-input                    Don't read input, simply evaluate the expression given. Useful for creating docs from scratch.
+  -o, --output-format string          [yaml|y|json|j|props|p|xml|x] output format type. (default "yaml")
+  -P, --prettyPrint                   pretty print, shorthand for '... style = ""'
+  -s, --split-exp string              print each result (or doc) into a file named (exp). [exp] argument must return a string. You can use $index in the expression as the result counter.
+      --unwrapScalar                  unwrap scalar, print the value with no quotes, colors or comments (default true)
+  -v, --verbose                       verbose mode
+  -V, --version                       Print version information and quit
+      --xml-attribute-prefix string   prefix for xml attributes (default "+")
+      --xml-content-name string       name for xml content (if no attribute name is present). (default "+content")
+
+Use "yq [command] --help" for more information about a command.
+```
+## Known Issues / Missing Features
+- `yq` attempts to preserve comment positions and whitespace as much as possible, but it does not handle all scenarios (see https://github.com/go-yaml/yaml/tree/v3 for details)
+- Powershell has its own...[opinions on quoting yq](https://mikefarah.gitbook.io/yq/usage/tips-and-tricks#quotes-in-windows-powershell)
+
+See [tips and tricks](https://mikefarah.gitbook.io/yq/usage/tips-and-tricks) for more common problems and solutions.

acceptance_tests/bad_args.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+
+testWriteInPlacePipeIn() {
+  result=$(./yq e -i -n '.a' 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: write inplace flag only applicable when giving an expression and at least one file" "$result"
+}
+
+testWriteInPlacePipeInEvalall() {
+  result=$(./yq ea -i -n '.a' 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: write inplace flag only applicable when giving an expression and at least one file" "$result"
+}
+
+testWriteInPlaceWithSplit() {
+  result=$(./yq e -s "cat" -i '.a = "thing"' test.yml 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: write inplace cannot be used with split file" "$result"
+}
+
+testWriteInPlaceWithSplitEvalAll() {
+  result=$(./yq ea -s "cat" -i '.a = "thing"' test.yml 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: write inplace cannot be used with split file" "$result"
+}
+
+testNullWithFiles() {
+  result=$(./yq e -n '.a = "thing"' test.yml 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: cannot pass files in when using null-input flag" "$result"
+}
+
+testNullWithFilesEvalAll() {
+  result=$(./yq ea -n '.a = "thing"' test.yml 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: cannot pass files in when using null-input flag" "$result"
+}
+
+
+
+source ./scripts/shunit2

acceptance_tests/basic.sh

@@ -0,0 +1,356 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml 2>/dev/null || true
+  rm .xyz 2>/dev/null || true
+  rm instructions.txt 2>/dev/null || true
+}
+
+testBasicEvalRoundTrip() {
+  ./yq -n ".a = 123" > test.yml
+  X=$(./yq '.a' test.yml)
+  assertEquals 123 "$X"
+}
+
+testBasicTrailingContent() {
+  cat >test-trailing.yml <<EOL
+test:
+# this comment will be removed
+EOL
+
+  read -r -d '' expected << EOM
+test:
+# this comment will be removed
+EOM
+  X=$(./yq test-trailing.yml -P)
+  assertEquals "$expected" "$X"
+}
+
+testBasicTrailingContent() {
+  cat >test-trailing.yml <<EOL
+test:
+# this comment will be removed
+EOL
+
+  read -r -d '' expected << EOM
+test:
+# hi
+EOM
+  X=$(./yq '. footComment = "hi"' test-trailing.yml)
+  assertEquals "$expected" "$X"
+}
+
+testBasicTrailingContentEvalAll() {
+  cat >test-trailing.yml <<EOL
+test:
+# this comment will be removed
+EOL
+
+  read -r -d '' expected << EOM
+test:
+# this comment will be removed
+EOM
+  X=$(./yq ea test-trailing.yml -P)
+  assertEquals "$expected" "$X"
+}
+
+testBasicTrailingContentEvalAll() {
+  cat >test-trailing.yml <<EOL
+test:
+# this comment will be removed
+EOL
+
+  read -r -d '' expected << EOM
+test:
+# hi
+EOM
+  X=$(./yq ea '. footComment = "hi"' test-trailing.yml)
+  assertEquals "$expected" "$X"
+}
+
+testBasicPipeWithDot() {
+  ./yq -n ".a = 123" > test.yml
+  X=$(cat test.yml | ./yq '.')
+  assertEquals "a: 123" "$X"
+}
+
+testBasicExpressionMatchesFileName() {
+  ./yq -n ".xyz = 123" > test.yml
+  touch .xyz
+  
+  X=$(./yq --expression '.xyz' test.yml)
+  assertEquals "123" "$X"
+
+  X=$(./yq ea --expression '.xyz' test.yml)
+  assertEquals "123" "$X"
+}
+
+testBasicExpressionFromFile() {
+  ./yq -n ".xyz = 123" > test.yml
+  echo '.xyz = "meow" | .cool = "frog"' > instructions.txt
+  
+  X=$(./yq --from-file instructions.txt test.yml -o=j -I=0)
+  assertEquals '{"xyz":"meow","cool":"frog"}' "$X"
+
+  X=$(./yq ea --from-file instructions.txt test.yml -o=j -I=0)
+  assertEquals '{"xyz":"meow","cool":"frog"}' "$X"
+}
+
+testBasicGitHubAction() {
+  ./yq -n ".a = 123" > test.yml
+  X=$(cat /dev/null | ./yq test.yml)
+  assertEquals "a: 123" "$X"
+
+  X=$(cat /dev/null | ./yq e test.yml)
+  assertEquals "a: 123" "$X"
+
+  X=$(cat /dev/null | ./yq ea test.yml)
+  assertEquals "a: 123" "$X"
+}
+
+testBasicGitHubActionWithExpression() {
+  ./yq -n ".a = 123" > test.yml
+  X=$(cat /dev/null | ./yq '.a' test.yml)
+  assertEquals "123" "$X"
+
+  X=$(cat /dev/null | ./yq e '.a' test.yml)
+  assertEquals "123" "$X"
+
+  X=$(cat /dev/null | ./yq ea '.a' test.yml)
+  assertEquals "123" "$X"
+}
+
+
+testBasicEvalAllAllFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(./yq ea test.yml test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+# when given a file, don't read STDIN
+# otherwise strange things start happening
+# in scripts
+# https://github.com/mikefarah/yq/issues/1115
+
+testBasicCatWithFilesNoDash() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq test2.yml)
+  Y=$(./yq e '.' test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+# when the nullinput flag is used
+# dont automatically read STDIN (this breaks github actions)
+testBasicCreateFileGithubAction() {
+  cat /dev/null | ./yq -n ".a = 123" > test.yml
+}
+
+testBasicEvalAllCatWithFilesNoDash() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq ea test2.yml)
+  Y=$(./yq e '.' test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicCatWithFilesNoDashWithExp() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq '.a' test2.yml)
+  Y=$(./yq e '.a' test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalAllCatWithFilesNoDashWithExp() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq ea '.a' test2.yml)
+  Y=$(./yq e '.a' test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+
+testBasicStdInWithFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq - test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalAllStdInWithFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq ea - test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicStdInWithFilesReverse() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq test2.yml -)
+  Y=$(./yq e '.' test2.yml test.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalAllStdInWithFilesReverse() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq ea test2.yml -)
+  Y=$(./yq e '.' test2.yml test.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalRoundTripNoEval() {
+  ./yq -n ".a = 123" > test.yml
+  X=$(./yq '.a' test.yml)
+  assertEquals 123 "$X"
+}
+
+testBasicStdInWithOneArg() {
+  ./yq e -n ".a = 123" > test.yml
+  X=$(cat test.yml | ./yq e ".a")
+  assertEquals 123 "$X"
+
+  X=$(cat test.yml | ./yq ea ".a")
+  assertEquals 123 "$X"
+
+  X=$(cat test.yml | ./yq ".a")
+  assertEquals 123 "$X"
+}
+
+testBasicUpdateInPlaceSequence() {
+  cat >test.yml <<EOL
+a: 0
+EOL
+  ./yq e -i ".a = 10" test.yml
+  X=$(./yq e '.a' test.yml)
+  assertEquals "10" "$X"
+}
+
+testBasicUpdateInPlaceSequenceNoEval() {
+  cat >test.yml <<EOL
+a: 0
+EOL
+  ./yq -i ".a = 10" test.yml
+  X=$(./yq '.a' test.yml)
+  assertEquals "10" "$X"
+}
+
+testBasicUpdateInPlaceSequenceEvalAll() {
+  cat >test.yml <<EOL
+a: 0
+EOL
+  ./yq ea -i ".a = 10" test.yml
+  X=$(./yq e '.a' test.yml)
+  assertEquals "10" "$X"
+}
+
+testBasicUpdateInPlaceMultipleFilesNoExpressionEval() {
+  cat >test.yml <<EOL
+a: 0
+EOL
+  cat >test2.yml <<EOL
+a: 1
+EOL
+read -r -d '' expected << EOM
+0
+---
+1
+EOM
+  ./yq -i test.yml test2.yml
+  X=$(./yq e '.a' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testBasicUpdateInPlaceMultipleFilesNoExpressionEvalAll() {
+  cat >test.yml <<EOL
+a: 0
+EOL
+  cat >test2.yml <<EOL
+a: 1
+EOL
+read -r -d '' expected << EOM
+0
+---
+1
+EOM
+  ./yq -i ea test.yml test2.yml
+  X=$(./yq e '.a' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testBasicNoExitStatus() {
+  echo "a: cat" > test.yml
+  X=$(./yq e '.z' test.yml)
+  assertEquals "null" "$X"
+}
+
+testBasicExitStatus() {
+  echo "a: cat" > test.yml
+  X=$(./yq e -e '.z' test.yml 2&>/dev/null)
+  assertEquals 1 "$?"
+}
+
+testBasicExitStatusNoEval() {
+  echo "a: cat" > test.yml
+  X=$(./yq -e '.z' test.yml 2&>/dev/null)
+  assertEquals 1 "$?"
+}
+
+testBasicExtractFieldWithSeperator() {
+    cat >test.yml <<EOL
+---
+name: chart-name
+version: 1.2.3
+EOL
+  X=$(./yq e '.name' test.yml)
+  assertEquals "chart-name" "$X"
+}
+
+testBasicExtractMultipleFieldWithSeperator() {
+    cat >test.yml <<EOL
+---
+name: chart-name
+version: 1.2.3
+---
+name: thing
+version: 1.2.3
+EOL
+
+read -r -d '' expected << EOM
+chart-name
+---
+thing
+EOM
+  X=$(./yq e '.name' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testBasicMultiplyAssignMultiDoc() {
+      cat >test.yml <<EOL
+a: 1
+---
+b: 2
+EOL
+
+read -r -d '' expected << EOM
+a: 1
+c: 3
+---
+b: 2
+c: 3
+EOM
+
+
+  X=$(./yq '. *= {"c":3}' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+
+
+source ./scripts/shunit2

acceptance_tests/completion.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+testCompletionRuns() {
+    result=$(./yq __complete "" 2>&1)
+    assertEquals 0 $?
+    assertContains "$result" "Completion ended with directive:"
+}
+
+source ./scripts/shunit2

acceptance_tests/empty.sh

@@ -0,0 +1,83 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+  cat >test.yml <<EOL
+# comment
+EOL
+}
+
+testEmptyEval() {
+  X=$(./yq e test.yml)
+  expected=$(cat test.yml)
+  assertEquals 0 $?
+  assertEquals "$expected" "$X"
+}
+
+testEmptyEvalNoNewLine() {
+  echo -n "#comment" >test.yml
+  X=$(./yq e test.yml)
+  expected=$(cat test.yml)
+  assertEquals 0 $?
+  assertEquals "$expected" "$X"
+}
+
+testEmptyEvalNoNewLineWithExpression() {
+  echo -n "# comment" >test.yml
+  X=$(./yq e '.apple = "tree"' test.yml)
+  read -r -d '' expected << EOM
+# comment
+apple: tree
+EOM
+  assertEquals "$expected" "$X"
+}
+
+testEmptyEvalPipe() {
+  X=$(./yq e - < test.yml)
+  assertEquals 0 $?
+}
+
+testEmptyCommentsWithExpressionEval() {
+  read -r -d '' expected << EOM
+# comment
+apple: tree
+EOM
+
+  X=$(./yq e '.apple="tree"' test.yml)
+
+  assertEquals "$expected" "$X"
+}
+
+testEmptyCommentsWithExpressionEvalAll() {
+  read -r -d '' expected << EOM
+# comment
+apple: tree
+EOM
+
+  X=$(./yq ea '.apple="tree"' test.yml)
+
+  assertEquals "$expected" "$X"
+}
+
+testEmptyWithExpressionEval() {
+  rm test.yml
+  touch test.yml
+  expected="apple: tree"
+
+  X=$(./yq e '.apple="tree"' test.yml)
+
+  assertEquals "$expected" "$X"
+}
+
+testEmptyWithExpressionEvalAll() {
+  rm test.yml
+  touch test.yml
+  expected="apple: tree"
+
+  X=$(./yq ea '.apple="tree"' test.yml)
+
+  assertEquals "$expected" "$X"
+}
+
+
+source ./scripts/shunit2

acceptance_tests/front-matter.sh

@@ -0,0 +1,76 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+  cat >test.yml <<EOL
+---
+a: apple
+b: cat
+---
+not yaml
+c: at
+EOL
+}
+
+testFrontMatterProcessEval() {
+  read -r -d '' expected << EOM
+---
+a: apple
+b: dog
+---
+not yaml
+c: at
+EOM
+  ./yq e --front-matter="process" '.b = "dog"' test.yml -i
+  assertEquals "$expected" "$(cat test.yml)"
+}
+
+testFrontMatterProcessEvalAll() {
+  read -r -d '' expected << EOM
+---
+a: apple
+b: dog
+---
+not yaml
+c: at
+EOM
+  ./yq ea --front-matter="process" '.b = "dog"' test.yml -i
+  assertEquals "$expected" "$(cat test.yml)"
+}
+
+testFrontMatterExtractEval() {
+    cat >test.yml <<EOL
+a: apple
+b: cat
+---
+not yaml
+c: at
+EOL
+
+  read -r -d '' expected << EOM
+a: apple
+b: dog
+EOM
+  ./yq e --front-matter="extract" '.b = "dog"' test.yml -i
+  assertEquals "$expected" "$(cat test.yml)"
+}
+
+testFrontMatterExtractEvalAll() {
+  cat >test.yml <<EOL
+a: apple
+b: cat
+---
+not yaml
+c: at
+EOL
+
+  read -r -d '' expected << EOM
+a: apple
+b: dog
+EOM
+  ./yq ea --front-matter="extract" '.b = "dog"' test.yml -i
+  assertEquals "$expected" "$(cat test.yml)"
+}
+
+
+source ./scripts/shunit2

acceptance_tests/inputs-format.sh

@@ -0,0 +1,168 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml 2>/dev/null || true
+  rm test*.properties 2>/dev/null || true
+  rm test*.csv 2>/dev/null || true
+  rm test*.tsv 2>/dev/null || true
+  rm test*.xml 2>/dev/null || true
+}
+
+testInputProperties() {
+  cat >test.properties <<EOL
+mike.things = hello
+EOL
+
+  read -r -d '' expected << EOM
+mike:
+  things: hello
+EOM
+
+  X=$(./yq e -p=props test.properties)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=props test.properties)
+  assertEquals "$expected" "$X"
+}
+
+testInputPropertiesGitHubAction() {
+  cat >test.properties <<EOL
+mike.things = hello
+EOL
+
+  read -r -d '' expected << EOM
+mike:
+  things: hello
+EOM
+
+  X=$(cat /dev/null | ./yq e -p=props test.properties)
+  assertEquals "$expected" "$X"
+
+  X=$(cat /dev/null | ./yq ea -p=props test.properties)
+  assertEquals "$expected" "$X"
+}
+
+testInputCSV() {
+  cat >test.csv <<EOL
+fruit,yumLevel
+apple,5
+banana,4
+EOL
+
+  read -r -d '' expected << EOM
+- fruit: apple
+  yumLevel: 5
+- fruit: banana
+  yumLevel: 4
+EOM
+
+  X=$(./yq e -p=csv test.csv)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=csv test.csv)
+  assertEquals "$expected" "$X"
+}
+
+testInputTSV() {
+  cat >test.tsv <<EOL
+fruit	yumLevel
+apple	5
+banana	4
+EOL
+
+  read -r -d '' expected << EOM
+- fruit: apple
+  yumLevel: 5
+- fruit: banana
+  yumLevel: 4
+EOM
+
+  X=$(./yq e -p=t test.tsv)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=t test.tsv)
+  assertEquals "$expected" "$X"
+}
+
+
+
+
+testInputXml() {
+  cat >test.yml <<EOL
+<cat legs="4">BiBi</cat>
+EOL
+
+  read -r -d '' expected << EOM
+cat:
+  +content: BiBi
+  +legs: "4"
+EOM
+
+  X=$(./yq e -p=xml test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=xml test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testInputXmlNamespaces() {
+  cat >test.yml <<EOL
+<?xml version="1.0"?>
+<map xmlns="some-namespace" xmlns:xsi="some-instance" xsi:schemaLocation="some-url">
+</map>
+EOL
+
+  read -r -d '' expected << EOM
+map:
+  +xmlns: some-namespace
+  +xmlns:xsi: some-instance
+  +xsi:schemaLocation: some-url
+EOM
+
+  X=$(./yq e -p=xml test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=xml test.yml)
+  assertEquals "$expected" "$X"
+}
+
+
+testInputXmlStrict() {
+  cat >test.yml <<EOL
+<?xml version="1.0"?>
+<!DOCTYPE root [
+<!ENTITY writer "Catherine.">
+<!ENTITY copyright "(r) Great">
+]>
+<root>
+    <item>&writer;&copyright;</item>
+</root>
+EOL
+
+  X=$(./yq -p=xml --xml-strict-mode test.yml 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: bad file 'test.yml': XML syntax error on line 7: invalid character entity &writer;" "$X"
+
+  X=$(./yq ea -p=xml --xml-strict-mode test.yml 2>&1)
+  assertEquals "Error: bad file 'test.yml': XML syntax error on line 7: invalid character entity &writer;" "$X"
+}
+
+testInputXmlGithubAction() {
+  cat >test.yml <<EOL
+<cat legs="4">BiBi</cat>
+EOL
+
+  read -r -d '' expected << EOM
+cat:
+  +content: BiBi
+  +legs: "4"
+EOM
+
+  X=$(cat /dev/null | ./yq e -p=xml test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(cat /dev/null | ./yq ea -p=xml test.yml)
+  assertEquals "$expected" "$X"
+}
+
+source ./scripts/shunit2

acceptance_tests/leading-seperator.sh

@@ -0,0 +1,450 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+  cat >test.yml <<EOL
+---
+a: test
+EOL
+}
+
+testLeadingSeperatorWithDoc() {
+  cat >test.yml <<EOL
+# hi peeps
+# cool
+---
+a: test
+---
+b: cool
+EOL
+
+  read -r -d '' expected << EOM
+# hi peeps
+# cool
+---
+a: thing
+---
+b: cool
+EOM
+
+  X=$(./yq e '(select(di == 0) | .a) = "thing"' - < test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorPipeIntoEvalSeq() {
+  X=$(./yq e - < test.yml)
+  expected=$(cat test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorExtractField() {
+  X=$(./yq e '.a' - < test.yml)
+  assertEquals "test" "$X"
+}
+
+testLeadingSeperatorExtractFieldWithCommentsAfterSep() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+EOL
+  X=$(./yq e '.a' test.yml)
+  assertEquals "test" "$X"
+}
+
+testLeadingSeperatorExtractFieldWithCommentsBeforeSep() {
+  cat >test.yml <<EOL
+# hi peeps
+# cool
+---
+a: test
+EOL
+  X=$(./yq e '.a' test.yml)
+  assertEquals "test" "$X"
+}
+
+
+testLeadingSeperatorExtractFieldMultiDoc() {
+  cat >test.yml <<EOL
+---
+a: test
+---
+a: test2
+EOL
+
+  read -r -d '' expected << EOM
+test
+---
+test2
+EOM
+  X=$(./yq e '.a' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorExtractFieldMultiDocWithComments() {
+  cat >test.yml <<EOL
+# here
+---
+# there
+a: test
+# whereever
+---
+# you are
+a: test2
+# woop
+EOL
+
+  read -r -d '' expected << EOM
+test
+---
+test2
+EOM
+  X=$(./yq e '.a' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+
+testLeadingSeperatorEvalSeq() {
+  X=$(./yq e test.yml)
+  expected=$(cat test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorPipeIntoEvalAll() {
+  X=$(./yq ea - < test.yml)
+  expected=$(cat test.yml)
+  assertEquals "$expected" "$X"
+}
+
+
+testLeadingSeperatorEvalAll() {
+  X=$(./yq ea test.yml)
+  expected=$(cat test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalSimple() {
+  read -r -d '' expected << EOM
+---
+a: test
+---
+version: 3
+application: MyApp
+EOM
+
+
+  X=$(./yq e '.' test.yml examples/order.yaml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocInOneFile() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+---
+b: things
+EOL
+  expected=$(cat test.yml)
+  X=$(./yq e '.' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocInOneFileEvalAll() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+---
+b: things
+EOL
+  expected=$(cat test.yml)
+  X=$(./yq ea '.' test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalComments() {
+  cat >test.yml <<EOL
+# hi peeps
+# cool
+a: test
+EOL
+
+cat >test2.yml <<EOL
+# this is another doc
+# great
+b: sane
+EOL
+
+  read -r -d '' expected << EOM
+# hi peeps
+# cool
+a: test
+---
+# this is another doc
+# great
+b: sane
+EOM
+
+
+  X=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalCommentsTrailingSep() {
+  cat >test.yml <<EOL
+# hi peeps
+# cool
+---
+a: test
+EOL
+
+cat >test2.yml <<EOL
+# this is another doc
+# great
+---
+b: sane
+EOL
+
+  read -r -d '' expected << EOM
+# hi peeps
+# cool
+---
+a: test
+---
+# this is another doc
+# great
+---
+b: sane
+EOM
+
+
+  X=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiMultiDocEvalCommentsTrailingSep() {
+  cat >test.yml <<EOL
+# hi peeps
+# cool
+---
+a: test
+---
+a1: test2
+EOL
+
+cat >test2.yml <<EOL
+# this is another doc
+# great
+---
+b: sane
+---
+b2: cool
+EOL
+
+  read -r -d '' expected << EOM
+# hi peeps
+# cool
+---
+a: test
+---
+a1: test2
+---
+# this is another doc
+# great
+---
+b: sane
+---
+b2: cool
+EOM
+
+
+  X=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalCommentsLeadingSep() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+EOL
+
+cat >test2.yml <<EOL
+---
+# this is another doc
+# great
+b: sane
+EOL
+
+  read -r -d '' expected << EOM
+---
+# hi peeps
+# cool
+a: test
+---
+# this is another doc
+# great
+b: sane
+EOM
+
+
+  X=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+# https://github.com/mikefarah/yq/issues/919
+testLeadingSeparatorDoesNotBreakCommentsOnOtherFiles() {
+  cat >test.yml <<EOL
+# a1
+a: 1
+# a2
+EOL
+
+cat >test2.yml <<EOL
+# b1
+b: 2
+# b2
+EOL
+
+  read -r -d '' expected << EOM
+# a1
+a: 1
+# a2
+
+# b1
+b: 2
+# b2
+EOM
+
+
+  X=$(./yq ea 'select(fi == 0) * select(fi == 1)' test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalCommentsStripComments() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+---
+# this is another doc
+# great
+b: sane
+EOL
+
+  # it will be hard to remove that top level separator
+  read -r -d '' expected << EOM
+a: test
+---
+b: sane
+EOM
+
+  X=$(./yq e '... comments=""'  test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalCommentsLeadingSepNoDocFlag() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+---
+# this is another doc
+# great
+b: sane
+EOL
+
+  read -r -d '' expected << EOM
+# hi peeps
+# cool
+a: test
+# this is another doc
+# great
+b: sane
+EOM
+
+
+  X=$(./yq e '.' --no-doc test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalJsonFlag() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+EOL
+
+cat >test2.yml <<EOL
+---
+# this is another doc
+# great
+b: sane
+EOL
+
+  read -r -d '' expected << EOM
+{
+  "a": "test"
+}
+{
+  "b": "sane"
+}
+EOM
+
+
+  X=$(./yq e '.' -j test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalAllJsonFlag() {
+  cat >test.yml <<EOL
+---
+# hi peeps
+# cool
+a: test
+EOL
+
+cat >test2.yml <<EOL
+---
+# this is another doc
+# great
+b: sane
+EOL
+
+  read -r -d '' expected << EOM
+{
+  "a": "test"
+}
+{
+  "b": "sane"
+}
+EOM
+
+
+  X=$(./yq ea '.' -j test.yml test2.yml)
+  assertEquals "$expected" "$X"
+}
+
+testLeadingSeperatorMultiDocEvalAll() {
+  read -r -d '' expected << EOM
+---
+a: test
+---
+version: 3
+application: MyApp
+EOM
+
+
+  X=$(./yq ea '.' test.yml examples/order.yaml)
+  assertEquals "$expected" "$X"
+}
+
+source ./scripts/shunit2

acceptance_tests/load-file.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+testLoadFileNotExist() {
+  result=$(./yq e -n 'load("cat.yml")' 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: Failed to load cat.yml: open cat.yml: no such file or directory" "$result"
+}
+
+testLoadFileExpNotExist() {
+  result=$(./yq e -n 'load(.a)' 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: Filename expression returned nil" "$result"
+}
+
+testStrLoadFileNotExist() {
+  result=$(./yq e -n 'strload("cat.yml")' 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: Failed to load cat.yml: open cat.yml: no such file or directory" "$result"
+}
+
+testStrLoadFileExpNotExist() {
+  result=$(./yq e -n 'strload(.a)' 2>&1)
+  assertEquals 1 $?
+  assertEquals "Error: Filename expression returned nil" "$result"
+}
+
+source ./scripts/shunit2

acceptance_tests/output-format.sh

@@ -0,0 +1,208 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+}
+
+testOutputJsonDeprecated() {
+  cat >test.yml <<EOL
+a: {b: ["cat"]}
+EOL
+
+  read -r -d '' expected << EOM
+{
+  "a": {
+    "b": [
+      "cat"
+    ]
+  }
+}
+EOM
+
+  X=$(./yq e -j test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -j test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputJson() {
+  cat >test.yml <<EOL
+a: {b: ["cat"]}
+EOL
+
+  read -r -d '' expected << EOM
+{
+  "a": {
+    "b": [
+      "cat"
+    ]
+  }
+}
+EOM
+
+  X=$(./yq e --output-format=json test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --output-format=json test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputJsonShort() {
+  cat >test.yml <<EOL
+a: {b: ["cat"]}
+EOL
+
+  read -r -d '' expected << EOM
+{
+  "a": {
+    "b": [
+      "cat"
+    ]
+  }
+}
+EOM
+
+  X=$(./yq e -o=j test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -o=j test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputProperties() {
+  cat >test.yml <<EOL
+a: {b: {c: ["cat"]}}
+EOL
+
+  read -r -d '' expected << EOM
+a.b.c.0 = cat
+EOM
+
+  X=$(./yq e --output-format=props test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --output-format=props test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputPropertiesShort() {
+  cat >test.yml <<EOL
+a: {b: {c: ["cat"]}}
+EOL
+
+  read -r -d '' expected << EOM
+a.b.c.0 = cat
+EOM
+
+  X=$(./yq e -o=p test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -o=p test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputCSV() {
+  cat >test.yml <<EOL
+- fruit: apple
+  yumLevel: 5
+- fruit: banana
+  yumLevel: 4
+EOL
+
+  read -r -d '' expected << EOM
+fruit,yumLevel
+apple,5
+banana,4
+EOM
+
+  X=$(./yq -o=c test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -o=csv test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputTSV() {
+  cat >test.yml <<EOL
+- fruit: apple
+  yumLevel: 5
+- fruit: banana
+  yumLevel: 4
+EOL
+
+  read -r -d '' expected << EOM
+fruit	yumLevel
+apple	5
+banana	4
+EOM
+
+  X=$(./yq -o=t test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -o=tsv test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputXml() {
+  cat >test.yml <<EOL
+a: {b: {c: ["cat"]}}
+EOL
+
+  read -r -d '' expected << EOM
+<a>
+  <b>
+    <c>cat</c>
+  </b>
+</a>
+EOM
+
+  X=$(./yq e --output-format=xml test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --output-format=xml test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputXmlShort() {
+  cat >test.yml <<EOL
+a: {b: {c: ["cat"]}}
+EOL
+
+  read -r -d '' expected << EOM
+<a>
+  <b>
+    <c>cat</c>
+  </b>
+</a>
+EOM
+
+  X=$(./yq e --output-format=x test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --output-format=x test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputXmComplex() {
+  cat >test.yml <<EOL
+a: {b: {c: ["cat", "dog"], +f: meow}}
+EOL
+
+  read -r -d '' expected << EOM
+<a>
+  <b f="meow">
+    <c>cat</c>
+    <c>dog</c>
+  </b>
+</a>
+EOM
+
+  X=$(./yq e --output-format=x test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --output-format=x test.yml)
+  assertEquals "$expected" "$X"
+}
+
+source ./scripts/shunit2

acceptance_tests/pipe.sh

@@ -0,0 +1,70 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+  cat >test.yml <<EOL
+a: frog
+EOL
+}
+
+testPipeViaCatWithParam() {
+  X=$(cat test.yml | ./yq '.a')
+  assertEquals "frog" "$X"
+}
+
+testPipeViaCatWithParamEval() {
+  X=$(cat test.yml | ./yq e '.a')
+  assertEquals "frog" "$X"
+}
+
+testPipeViaCatWithParamEvalAll() {
+  X=$(cat test.yml | ./yq ea '.a')
+  assertEquals "frog" "$X"
+}
+
+testPipeViaCatNoParam() {
+  X=$(cat test.yml | ./yq)
+  assertEquals "a: frog" "$X"
+}
+
+testPipeViaCatNoParamEval() {
+  X=$(cat test.yml | ./yq e)
+  assertEquals "a: frog" "$X"
+}
+
+testPipeViaCatNoParamEvalAll() {
+  X=$(cat test.yml | ./yq ea)
+  assertEquals "a: frog" "$X"
+}
+
+testPipeViaFileishWithParam() {
+  X=$(./yq '.a' < test.yml)
+  assertEquals "frog" "$X"
+}
+
+testPipeViaFileishWithParamEval() {
+  X=$(./yq e '.a' < test.yml)
+  assertEquals "frog" "$X"
+}
+
+testPipeViaFileishWithParamEvalAll() {
+  X=$(./yq ea '.a' < test.yml)
+  assertEquals "frog" "$X"
+}
+
+testPipeViaFileishNoParam() {
+  X=$(./yq < test.yml)
+  assertEquals "a: frog" "$X"
+}
+
+testPipeViaFileishNoParamEval() {
+  X=$(./yq e < test.yml)
+  assertEquals "a: frog" "$X"
+}
+
+testPipeViaFileishNoParamEvalAll() {
+  X=$(./yq ea < test.yml)
+  assertEquals "a: frog" "$X"
+}
+
+source ./scripts/shunit2

acceptance_tests/pretty-print.sh

@@ -0,0 +1,176 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+}
+
+testPrettyPrintWithBooleans() {
+  cat >test.yml <<EOL
+leaveUnquoted: [yes, no, on, off, y, n, true, false]
+leaveQuoted: ["yes", "no", "on", "off", "y", "n", "true", "false"]
+
+EOL
+
+  read -r -d '' expected << EOM
+leaveUnquoted:
+  - yes
+  - no
+  - on
+  - off
+  - y
+  - n
+  - true
+  - false
+leaveQuoted:
+  - "yes"
+  - "no"
+  - "on"
+  - "off"
+  - "y"
+  - "n"
+  - "true"
+  - "false"
+EOM
+
+  X=$(./yq e --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testPrettyPrintWithBooleansCapitals() {
+  cat >test.yml <<EOL
+leaveUnquoted: [YES, NO, ON, OFF, Y, N, TRUE, FALSE]
+leaveQuoted: ["YES", "NO", "ON", "OFF", "Y", "N", "TRUE", "FALSE"]
+EOL
+
+  read -r -d '' expected << EOM
+leaveUnquoted:
+  - YES
+  - NO
+  - ON
+  - OFF
+  - Y
+  - N
+  - TRUE
+  - FALSE
+leaveQuoted:
+  - "YES"
+  - "NO"
+  - "ON"
+  - "OFF"
+  - "Y"
+  - "N"
+  - "TRUE"
+  - "FALSE"
+EOM
+
+  X=$(./yq e --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testPrettyPrintOtherStringValues() {
+  cat >test.yml <<EOL
+leaveUnquoted: [yesSir, hellno, bonapite]
+makeUnquoted: ["yesSir", "hellno", "bonapite"]
+EOL
+
+  read -r -d '' expected << EOM
+leaveUnquoted:
+  - yesSir
+  - hellno
+  - bonapite
+makeUnquoted:
+  - yesSir
+  - hellno
+  - bonapite
+EOM
+
+  X=$(./yq e --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testPrettyPrintKeys() {
+  cat >test.yml <<EOL
+"removeQuotes": "please"
+EOL
+
+  read -r -d '' expected << EOM
+removeQuotes: please
+EOM
+
+  X=$(./yq e --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testPrettyPrintOtherStringValues() {
+  cat >test.yml <<EOL
+leaveUnquoted: [yesSir, hellno, bonapite]
+makeUnquoted: ["yesSir", "hellno", "bonapite"]
+EOL
+
+  read -r -d '' expected << EOM
+leaveUnquoted:
+  - yesSir
+  - hellno
+  - bonapite
+makeUnquoted:
+  - yesSir
+  - hellno
+  - bonapite
+EOM
+
+  X=$(./yq e --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testPrettyPrintStringBlocks() {
+  cat >test.yml <<EOL
+"removeQuotes": | 
+  "please"
+EOL
+
+  read -r -d '' expected << EOM
+removeQuotes: |
+  "please"
+EOM
+
+  X=$(./yq e --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testPrettyPrintWithExpression() {
+  cat >test.yml <<EOL
+a: {b: {c: ["cat"]}}
+EOL
+
+  read -r -d '' expected << EOM
+b:
+  c:
+    - cat
+EOM
+
+  X=$(./yq e '.a' --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea '.a' --prettyPrint test.yml)
+  assertEquals "$expected" "$X"
+}
+
+source ./scripts/shunit2

acceptance_tests/split-printer.sh

@@ -0,0 +1,207 @@
+#!/bin/bash
+
+setUp() {
+  rm test*.yml || true
+}
+
+testBasicSplitWithName() {
+  cat >test.yml <<EOL
+a: test_doc1
+--- 
+a: test_doc2
+EOL
+
+  ./yq e test.yml -s ".a"
+
+  doc1=$(cat test_doc1.yml)
+  
+  assertEquals "a: test_doc1" "$doc1"
+
+  doc2=$(cat test_doc2.yml)
+  read -r -d '' expectedDoc2 << EOM
+---
+a: test_doc2
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+testBasicSplitWithNameCustomExtension() {
+  rm test*.yaml || true
+  cat >test.yml <<EOL
+a: test_doc1
+--- 
+a: test_doc2
+EOL
+
+  ./yq e test.yml -s '.a + ".yaml"'
+
+  doc1=$(cat test_doc1.yaml)
+  
+  assertEquals "a: test_doc1" "$doc1"
+
+  doc2=$(cat test_doc2.yaml)
+  read -r -d '' expectedDoc2 << EOM
+---
+a: test_doc2
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+
+
+
+testSplitFromFile() {
+  cat >test.yml <<EOL
+a: test_doc1
+--- 
+a: test_doc2
+EOL
+
+cat >test_splitExp.yml <<EOL
+.a
+EOL
+
+  ./yq test.yml --split-exp-file test_splitExp.yml
+
+  doc1=$(cat test_doc1.yml)
+  
+  assertEquals "a: test_doc1" "$doc1"
+
+  doc2=$(cat test_doc2.yml)
+  read -r -d '' expectedDoc2 << EOM
+---
+a: test_doc2
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+testBasicSplitWithNameEvalAll() {
+  cat >test.yml <<EOL
+a: test_doc1
+--- 
+a: test_doc2
+EOL
+
+  ./yq ea test.yml -s ".a"
+
+  doc1=$(cat test_doc1.yml)
+  
+  assertEquals "a: test_doc1" "$doc1"
+
+  doc2=$(cat test_doc2.yml)
+  read -r -d '' expectedDoc2 << EOM
+---
+a: test_doc2
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+testBasicSplitWithIndex() {
+  cat >test.yml <<EOL
+a: test_doc1
+--- 
+a: test_doc2
+EOL
+
+  ./yq e test.yml -s '"test_" + $index'
+
+  doc1=$(cat test_0.yml)
+  
+  assertEquals "a: test_doc1" "$doc1"
+
+  doc2=$(cat test_1.yml)
+  read -r -d '' expectedDoc2 << EOM
+---
+a: test_doc2
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+testBasicSplitWithIndexEvalAll() {
+  cat >test.yml <<EOL
+a: test_doc1
+--- 
+a: test_doc2
+EOL
+
+  ./yq ea test.yml -s '"test_" + $index'
+
+  doc1=$(cat test_0.yml)
+  
+  assertEquals "a: test_doc1" "$doc1"
+
+  doc2=$(cat test_1.yml)
+  read -r -d '' expectedDoc2 << EOM
+---
+a: test_doc2
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+
+testArraySplitWithNameNoSeparators() {
+  cat >test.yml <<EOL
+- name: test_fred
+  age: 35
+- name: test_catherine
+  age: 37
+EOL
+
+  ./yq e --no-doc -s ".name"  ".[]" test.yml 
+
+  doc1=$(cat test_fred.yml)
+  read -r -d '' expectedDoc1 << EOM
+name: test_fred
+age: 35
+EOM
+
+  assertEquals "$expectedDoc1" "$doc1"
+
+  doc2=$(cat test_catherine.yml)
+  read -r -d '' expectedDoc2 << EOM
+name: test_catherine
+age: 37
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+}
+
+testArraySplitWithNameNoSeparatorsEvalAll() {
+  cat >test.yml <<EOL
+- name: test_fred
+  age: 35
+- name: test_catherine
+  age: 37
+EOL
+
+cat >test2.yml <<EOL
+- name: test_mike
+  age: 564
+EOL
+
+  ./yq ea --no-doc -s ".name"  ".[]" test.yml test2.yml
+
+  doc1=$(cat test_fred.yml)
+  read -r -d '' expectedDoc1 << EOM
+name: test_fred
+age: 35
+EOM
+
+  assertEquals "$expectedDoc1" "$doc1"
+
+  doc2=$(cat test_catherine.yml)
+  read -r -d '' expectedDoc2 << EOM
+name: test_catherine
+age: 37
+EOM
+  assertEquals "$expectedDoc2" "$doc2"
+
+
+  doc3=$(cat test_mike.yml)
+  read -r -d '' expectedDoc3 << EOM
+name: test_mike
+age: 564
+EOM
+  assertEquals "$expectedDoc3" "$doc3"
+}
+
+source ./scripts/shunit2

action.yml

@@ -0,0 +1,17 @@
+name: 'yq - portable yaml processor'
+description: 'create, read, update, delete, merge, validate and do more with yaml'
+branding:
+  icon: command
+  color: gray-dark
+inputs:
+  cmd:
+    description: 'The Command which should be run'
+    required: true
+outputs:
+  result:
+    description: "The complete result from the yq command being run"
+runs:
+  using: 'docker'
+  image: 'github-action/Dockerfile'
+  args:
+    - ${{ inputs.cmd }}

cmd/constant.go

@@ -0,0 +1,38 @@
+package cmd
+
+var leadingContentPreProcessing = true
+var unwrapScalar = true
+
+var writeInplace = false
+var outputToJSON = false
+var outputFormat = "yaml"
+var inputFormat = "yaml"
+
+var xmlAttributePrefix = "+"
+var xmlContentName = "+content"
+var xmlStrictMode = false
+var xmlKeepNamespace = true
+var xmlUseRawToken = true
+
+var exitStatus = false
+var forceColor = false
+var forceNoColor = false
+var colorsEnabled = false
+var indent = 2
+var noDocSeparators = false
+var nullInput = false
+var verbose = false
+var version = false
+var prettyPrint = false
+
+// can be either "" (off), "extract" or "process"
+var frontMatter = ""
+
+var splitFileExp = ""
+var splitFileExpFile = ""
+
+var completedSuccessfully = false
+
+var forceExpression = ""
+
+var expressionFile = ""

cmd/evaluate_all_command.go

@@ -0,0 +1,128 @@
+package cmd
+
+import (
+	"errors"
+
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
+	"github.com/spf13/cobra"
+)
+
+func createEvaluateAllCommand() *cobra.Command {
+	var cmdEvalAll = &cobra.Command{
+		Use:     "eval-all [expression] [yaml_file1]...",
+		Aliases: []string{"ea"},
+		Short:   "Loads _all_ yaml documents of _all_ yaml files and runs expression once",
+		Example: `
+# Merge f2.yml into f1.yml (inplace)
+yq eval-all --inplace 'select(fileIndex == 0) * select(fileIndex == 1)' f1.yml f2.yml
+## the same command and expression using shortened names:
+yq ea -i 'select(fi == 0) * select(fi == 1)' f1.yml f2.yml
+
+
+# Merge all given files
+yq ea '. as $item ireduce ({}; . * $item )' file1.yml file2.yml ...
+
+# Pipe from STDIN
+## use '-' as a filename to pipe from STDIN
+cat file2.yml | yq ea '.a.b' file1.yml - file3.yml
+`,
+		Long: `yq is a portable command-line YAML processor (https://github.com/mikefarah/yq/) 
+See https://mikefarah.gitbook.io/yq/ for detailed documentation and examples.
+
+## Evaluate All ##
+This command loads _all_ yaml documents of _all_ yaml files and runs expression once
+Useful when you need to run an expression across several yaml documents or files (like merge).
+Note that it consumes more memory than eval.
+`,
+		RunE: evaluateAll,
+	}
+	return cmdEvalAll
+}
+func evaluateAll(cmd *cobra.Command, args []string) (cmdError error) {
+	// 0 args, read std in
+	// 1 arg, null input, process expression
+	// 1 arg, read file in sequence
+	// 2+ args, [0] = expression, file the rest
+
+	var err error
+
+	expression, args, err := initCommand(cmd, args)
+	if err != nil {
+		return err
+	}
+
+	out := cmd.OutOrStdout()
+
+	if writeInplace {
+		// only use colors if its forced
+		colorsEnabled = forceColor
+		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[0])
+		out, err = writeInPlaceHandler.CreateTempFile()
+		if err != nil {
+			return err
+		}
+		// need to indirectly call the function so  that completedSuccessfully is
+		// passed when we finish execution as opposed to now
+		defer func() {
+			if cmdError == nil {
+				cmdError = writeInPlaceHandler.FinishWriteInPlace(completedSuccessfully)
+			}
+		}()
+	}
+
+	format, err := yqlib.OutputFormatFromString(outputFormat)
+	if err != nil {
+		return err
+	}
+
+	decoder, err := configureDecoder()
+	if err != nil {
+		return err
+	}
+
+	printerWriter, err := configurePrinterWriter(format, out)
+	if err != nil {
+		return err
+	}
+	encoder := configureEncoder(format)
+
+	printer := yqlib.NewPrinter(encoder, printerWriter)
+
+	if frontMatter != "" {
+		frontMatterHandler := yqlib.NewFrontMatterHandler(args[0])
+		err = frontMatterHandler.Split()
+		if err != nil {
+			return err
+		}
+		args[0] = frontMatterHandler.GetYamlFrontMatterFilename()
+
+		if frontMatter == "process" {
+			reader := frontMatterHandler.GetContentReader()
+			printer.SetAppendix(reader)
+			defer yqlib.SafelyCloseReader(reader)
+		}
+		defer frontMatterHandler.CleanUp()
+	}
+
+	allAtOnceEvaluator := yqlib.NewAllAtOnceEvaluator()
+
+	switch len(args) {
+	case 0:
+		if nullInput {
+			err = yqlib.NewStreamEvaluator().EvaluateNew(processExpression(expression), printer, "")
+		} else {
+			cmd.Println(cmd.UsageString())
+			return nil
+		}
+	default:
+		err = allAtOnceEvaluator.EvaluateFiles(processExpression(expression), args, printer, leadingContentPreProcessing, decoder)
+	}
+
+	completedSuccessfully = err == nil
+
+	if err == nil && exitStatus && !printer.PrintedAnything() {
+		return errors.New("no matches found")
+	}
+
+	return err
+}

cmd/evalute_sequence_command.go

@@ -0,0 +1,141 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
+	"github.com/spf13/cobra"
+)
+
+func createEvaluateSequenceCommand() *cobra.Command {
+	var cmdEvalSequence = &cobra.Command{
+		Use:     "eval [expression] [yaml_file1]...",
+		Aliases: []string{"e"},
+		Short:   "(default) Apply the expression to each document in each yaml file in sequence",
+		Example: `
+# Reads field under the given path for each file
+yq e '.a.b' f1.yml f2.yml 
+
+# Prints out the file
+yq e sample.yaml 
+
+# Pipe from STDIN
+## use '-' as a filename to pipe from STDIN
+cat file2.yml | yq e '.a.b' file1.yml - file3.yml
+
+# Creates a new yaml document
+## Note that editing an empty file does not work.
+yq e -n '.a.b.c = "cat"' 
+
+# Update a file inplace
+yq e '.a.b = "cool"' -i file.yaml 
+`,
+		Long: `yq is a portable command-line YAML processor (https://github.com/mikefarah/yq/) 
+See https://mikefarah.gitbook.io/yq/ for detailed documentation and examples.
+
+## Evaluate Sequence ##
+This command iterates over each yaml document from each given file, applies the 
+expression and prints the result in sequence.`,
+		RunE: evaluateSequence,
+	}
+	return cmdEvalSequence
+}
+
+func processExpression(expression string) string {
+
+	if prettyPrint && expression == "" {
+		return yqlib.PrettyPrintExp
+	} else if prettyPrint {
+		return fmt.Sprintf("%v | %v", expression, yqlib.PrettyPrintExp)
+	}
+	return expression
+}
+
+func evaluateSequence(cmd *cobra.Command, args []string) (cmdError error) {
+	// 0 args, read std in
+	// 1 arg, null input, process expression
+	// 1 arg, read file in sequence
+	// 2+ args, [0] = expression, file the rest
+
+	out := cmd.OutOrStdout()
+
+	var err error
+
+	expression, args, err := initCommand(cmd, args)
+	if err != nil {
+		return err
+	}
+
+	if writeInplace {
+		// only use colors if its forced
+		colorsEnabled = forceColor
+		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[0])
+		out, err = writeInPlaceHandler.CreateTempFile()
+		if err != nil {
+			return err
+		}
+		// need to indirectly call the function so  that completedSuccessfully is
+		// passed when we finish execution as opposed to now
+		defer func() {
+			if cmdError == nil {
+				cmdError = writeInPlaceHandler.FinishWriteInPlace(completedSuccessfully)
+			}
+		}()
+	}
+
+	format, err := yqlib.OutputFormatFromString(outputFormat)
+	if err != nil {
+		return err
+	}
+
+	printerWriter, err := configurePrinterWriter(format, out)
+	if err != nil {
+		return err
+	}
+	encoder := configureEncoder(format)
+
+	printer := yqlib.NewPrinter(encoder, printerWriter)
+
+	decoder, err := configureDecoder()
+	if err != nil {
+		return err
+	}
+	streamEvaluator := yqlib.NewStreamEvaluator()
+
+	if frontMatter != "" {
+		yqlib.GetLogger().Debug("using front matter handler")
+		frontMatterHandler := yqlib.NewFrontMatterHandler(args[0])
+		err = frontMatterHandler.Split()
+		if err != nil {
+			return err
+		}
+		args[0] = frontMatterHandler.GetYamlFrontMatterFilename()
+
+		if frontMatter == "process" {
+			reader := frontMatterHandler.GetContentReader()
+			printer.SetAppendix(reader)
+			defer yqlib.SafelyCloseReader(reader)
+		}
+		defer frontMatterHandler.CleanUp()
+	}
+
+	switch len(args) {
+	case 0:
+		if nullInput {
+			err = streamEvaluator.EvaluateNew(processExpression(expression), printer, "")
+		} else {
+			cmd.Println(cmd.UsageString())
+			return nil
+		}
+	default:
+		err = streamEvaluator.EvaluateFiles(processExpression(expression), args, printer, leadingContentPreProcessing, decoder)
+	}
+	completedSuccessfully = err == nil
+
+	if err == nil && exitStatus && !printer.PrintedAnything() {
+		return errors.New("no matches found")
+	}
+
+	return err
+}

cmd/root.go

@@ -0,0 +1,105 @@
+package cmd
+
+import (
+	"os"
+
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
+	"github.com/spf13/cobra"
+	logging "gopkg.in/op/go-logging.v1"
+)
+
+func New() *cobra.Command {
+	var rootCmd = &cobra.Command{
+		Use:   "yq",
+		Short: "yq is a lightweight and portable command-line YAML processor.",
+		Long: `yq is a portable command-line YAML processor (https://github.com/mikefarah/yq/) 
+See https://mikefarah.gitbook.io/yq/ for detailed documentation and examples.`,
+		Example: `
+# yq defaults to 'eval' command if no command is specified. See "yq eval --help" for more examples.
+
+# read the "stuff" node from "myfile.yml"
+yq '.stuff' < myfile.yml
+
+# update myfile.yml in place
+yq -i '.stuff = "foo"' myfile.yml
+
+# print contents of sample.json as idiomatic YAML
+yq -P sample.json
+`,
+
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if version {
+				cmd.Print(GetVersionDisplay())
+				return nil
+			}
+			return evaluateSequence(cmd, args)
+
+		},
+		PersistentPreRun: func(cmd *cobra.Command, args []string) {
+			cmd.SetOut(cmd.OutOrStdout())
+
+			var format = logging.MustStringFormatter(
+				`%{color}%{time:15:04:05} %{shortfunc} [%{level:.4s}]%{color:reset} %{message}`,
+			)
+			var backend = logging.AddModuleLevel(
+				logging.NewBackendFormatter(logging.NewLogBackend(os.Stderr, "", 0), format))
+
+			if verbose {
+				backend.SetLevel(logging.DEBUG, "")
+			} else {
+				backend.SetLevel(logging.ERROR, "")
+			}
+
+			logging.SetBackend(backend)
+			yqlib.InitExpressionParser()
+			yqlib.XMLPreferences.AttributePrefix = xmlAttributePrefix
+			yqlib.XMLPreferences.ContentName = xmlContentName
+			yqlib.XMLPreferences.StrictMode = xmlStrictMode
+		},
+	}
+
+	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "verbose mode")
+
+	rootCmd.PersistentFlags().BoolVarP(&outputToJSON, "tojson", "j", false, "(deprecated) output as json. Set indent to 0 to print json in one line.")
+	err := rootCmd.PersistentFlags().MarkDeprecated("tojson", "please use -o=json instead")
+	if err != nil {
+		panic(err)
+	}
+
+	rootCmd.PersistentFlags().StringVarP(&outputFormat, "output-format", "o", "yaml", "[yaml|y|json|j|props|p|xml|x] output format type.")
+	rootCmd.PersistentFlags().StringVarP(&inputFormat, "input-format", "p", "yaml", "[yaml|y|props|p|xml|x] parse format for input. Note that json is a subset of yaml.")
+
+	rootCmd.PersistentFlags().StringVar(&xmlAttributePrefix, "xml-attribute-prefix", "+", "prefix for xml attributes")
+	rootCmd.PersistentFlags().StringVar(&xmlContentName, "xml-content-name", "+content", "name for xml content (if no attribute name is present).")
+	rootCmd.PersistentFlags().BoolVar(&xmlStrictMode, "xml-strict-mode", false, "enables strict parsing of XML. See https://pkg.go.dev/encoding/xml for more details.")
+	rootCmd.PersistentFlags().BoolVar(&xmlKeepNamespace, "xml-keep-namespace", true, "enables keeping namespace after parsing attributes")
+	rootCmd.PersistentFlags().BoolVar(&xmlUseRawToken, "xml-raw-token", true, "enables using RawToken method instead Token. Commonly disables namespace translations. See https://pkg.go.dev/encoding/xml#Decoder.RawToken for details.")
+
+	rootCmd.PersistentFlags().BoolVarP(&nullInput, "null-input", "n", false, "Don't read input, simply evaluate the expression given. Useful for creating docs from scratch.")
+	rootCmd.PersistentFlags().BoolVarP(&noDocSeparators, "no-doc", "N", false, "Don't print document separators (---)")
+
+	rootCmd.PersistentFlags().IntVarP(&indent, "indent", "I", 2, "sets indent level for output")
+	rootCmd.Flags().BoolVarP(&version, "version", "V", false, "Print version information and quit")
+	rootCmd.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the file inplace of first file given.")
+	rootCmd.PersistentFlags().BoolVarP(&unwrapScalar, "unwrapScalar", "r", true, "unwrap scalar, print the value with no quotes, colors or comments")
+	rootCmd.PersistentFlags().BoolVarP(&prettyPrint, "prettyPrint", "P", false, "pretty print, shorthand for '... style = \"\"'")
+	rootCmd.PersistentFlags().BoolVarP(&exitStatus, "exit-status", "e", false, "set exit status if there are no matches or null or false is returned")
+
+	rootCmd.PersistentFlags().BoolVarP(&forceColor, "colors", "C", false, "force print with colors")
+	rootCmd.PersistentFlags().BoolVarP(&forceNoColor, "no-colors", "M", false, "force print with no colors")
+	rootCmd.PersistentFlags().StringVarP(&frontMatter, "front-matter", "f", "", "(extract|process) first input as yaml front-matter. Extract will pull out the yaml content, process will run the expression against the yaml content, leaving the remaining data intact")
+	rootCmd.PersistentFlags().StringVarP(&forceExpression, "expression", "", "", "forcibly set the expression argument. Useful when yq argument detection thinks your expression is a file.")
+	rootCmd.PersistentFlags().BoolVarP(&leadingContentPreProcessing, "header-preprocess", "", true, "Slurp any header comments and separators before processing expression.")
+
+	rootCmd.PersistentFlags().StringVarP(&splitFileExp, "split-exp", "s", "", "print each result (or doc) into a file named (exp). [exp] argument must return a string. You can use $index in the expression as the result counter.")
+	rootCmd.PersistentFlags().StringVarP(&splitFileExpFile, "split-exp-file", "", "", "Use a file to specify the split-exp expression.")
+
+	rootCmd.PersistentFlags().StringVarP(&expressionFile, "from-file", "", "", "Load expression from specified file.")
+
+	rootCmd.AddCommand(
+		createEvaluateSequenceCommand(),
+		createEvaluateAllCommand(),
+		completionCmd,
+	)
+	return rootCmd
+}

cmd/shell-completion.go

@@ -0,0 +1,61 @@
+package cmd
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var completionCmd = &cobra.Command{
+	Use:   "shell-completion [bash|zsh|fish|powershell]",
+	Short: "Generate completion script",
+	Long: `To load completions:
+
+Bash:
+
+$ source <(yq shell-completion bash)
+
+# To load completions for each session, execute once:
+Linux:
+  $ yq shell-completion bash > /etc/bash_completion.d/yq
+MacOS:
+  $ yq shell-completion bash > /usr/local/etc/bash_completion.d/yq
+
+Zsh:
+
+# If shell completion is not already enabled in your environment you will need
+# to enable it.  You can execute the following once:
+
+$ echo "autoload -U compinit; compinit" >> ~/.zshrc
+
+# To load completions for each session, execute once:
+$ yq shell-completion zsh > "${fpath[1]}/_yq"
+
+# You will need to start a new shell for this setup to take effect.
+
+Fish:
+
+$ yq shell-completion fish | source
+
+# To load completions for each session, execute once:
+$ yq shell-completion fish > ~/.config/fish/completions/yq.fish
+`,
+	DisableFlagsInUseLine: true,
+	ValidArgs:             []string{"bash", "zsh", "fish", "powershell"},
+	Args:                  cobra.ExactValidArgs(1),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		var err error = nil
+		switch args[0] {
+		case "bash":
+			err = cmd.Root().GenBashCompletion(os.Stdout)
+		case "zsh":
+			err = cmd.Root().GenZshCompletion(os.Stdout)
+		case "fish":
+			err = cmd.Root().GenFishCompletion(os.Stdout, true)
+		case "powershell":
+			err = cmd.Root().GenPowerShellCompletion(os.Stdout)
+		}
+		return err
+
+	},
+}

cmd/utils.go

@@ -0,0 +1,177 @@
+package cmd
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
+	"github.com/spf13/cobra"
+	"gopkg.in/op/go-logging.v1"
+)
+
+func initCommand(cmd *cobra.Command, args []string) (string, []string, error) {
+	cmd.SilenceUsage = true
+
+	fileInfo, _ := os.Stdout.Stat()
+
+	if forceColor || (!forceNoColor && (fileInfo.Mode()&os.ModeCharDevice) != 0) {
+		colorsEnabled = true
+	}
+
+	expression, args, err := processArgs(args)
+	if err != nil {
+		return "", nil, err
+	}
+
+	if splitFileExpFile != "" {
+		splitExpressionBytes, err := os.ReadFile(splitFileExpFile)
+		if err != nil {
+			return "", nil, err
+		}
+		splitFileExp = string(splitExpressionBytes)
+	}
+
+	// backwards compatibility
+	if outputToJSON {
+		outputFormat = "json"
+	}
+
+	if writeInplace && (len(args) == 0 || args[0] == "-") {
+		return "", nil, fmt.Errorf("write inplace flag only applicable when giving an expression and at least one file")
+	}
+
+	if frontMatter != "" && len(args) == 0 {
+		return "", nil, fmt.Errorf("front matter flag only applicable when giving an expression and at least one file")
+	}
+
+	if writeInplace && splitFileExp != "" {
+		return "", nil, fmt.Errorf("write inplace cannot be used with split file")
+	}
+
+	if nullInput && len(args) > 0 {
+		return "", nil, fmt.Errorf("cannot pass files in when using null-input flag")
+	}
+
+	return expression, args, nil
+}
+
+func configureDecoder() (yqlib.Decoder, error) {
+	yqlibInputFormat, err := yqlib.InputFormatFromString(inputFormat)
+	if err != nil {
+		return nil, err
+	}
+	switch yqlibInputFormat {
+	case yqlib.XMLInputFormat:
+		return yqlib.NewXMLDecoder(xmlAttributePrefix, xmlContentName, xmlStrictMode, xmlKeepNamespace, xmlUseRawToken), nil
+	case yqlib.PropertiesInputFormat:
+		return yqlib.NewPropertiesDecoder(), nil
+	case yqlib.JsonInputFormat:
+		return yqlib.NewJSONDecoder(), nil
+	case yqlib.CSVObjectInputFormat:
+		return yqlib.NewCSVObjectDecoder(','), nil
+	case yqlib.TSVObjectInputFormat:
+		return yqlib.NewCSVObjectDecoder('\t'), nil
+	}
+
+	return yqlib.NewYamlDecoder(), nil
+}
+
+func configurePrinterWriter(format yqlib.PrinterOutputFormat, out io.Writer) (yqlib.PrinterWriter, error) {
+
+	var printerWriter yqlib.PrinterWriter
+
+	if splitFileExp != "" {
+		colorsEnabled = forceColor
+		splitExp, err := yqlib.ExpressionParser.ParseExpression(splitFileExp)
+		if err != nil {
+			return nil, fmt.Errorf("bad split document expression: %w", err)
+		}
+		printerWriter = yqlib.NewMultiPrinterWriter(splitExp, format)
+	} else {
+		printerWriter = yqlib.NewSinglePrinterWriter(out)
+	}
+	return printerWriter, nil
+}
+
+func configureEncoder(format yqlib.PrinterOutputFormat) yqlib.Encoder {
+	switch format {
+	case yqlib.JSONOutputFormat:
+		return yqlib.NewJSONEncoder(indent, colorsEnabled)
+	case yqlib.PropsOutputFormat:
+		return yqlib.NewPropertiesEncoder(unwrapScalar)
+	case yqlib.CSVOutputFormat:
+		return yqlib.NewCsvEncoder(',')
+	case yqlib.TSVOutputFormat:
+		return yqlib.NewCsvEncoder('\t')
+	case yqlib.YamlOutputFormat:
+		return yqlib.NewYamlEncoder(indent, colorsEnabled, !noDocSeparators, unwrapScalar)
+	case yqlib.XMLOutputFormat:
+		return yqlib.NewXMLEncoder(indent, xmlAttributePrefix, xmlContentName)
+	}
+	panic("invalid encoder")
+}
+
+// this is a hack to enable backwards compatibility with githubactions (which pipe /dev/null into everything)
+// and being able to call yq with the filename as a single parameter
+//
+// without this - yq detects there is stdin (thanks githubactions),
+// then tries to parse the filename as an expression
+func maybeFile(str string) bool {
+	yqlib.GetLogger().Debugf("checking '%v' is a file", str)
+	stat, err := os.Stat(str) // #nosec
+	result := err == nil && !stat.IsDir()
+	if yqlib.GetLogger().IsEnabledFor(logging.DEBUG) {
+		if err != nil {
+			yqlib.GetLogger().Debugf("error: %v", err)
+		} else {
+			yqlib.GetLogger().Debugf("error: %v, dir: %v", err, stat.IsDir())
+		}
+		yqlib.GetLogger().Debugf("result: %v", result)
+	}
+	return result
+}
+
+func processStdInArgs(args []string) []string {
+	stat, _ := os.Stdin.Stat()
+	pipingStdin := (stat.Mode() & os.ModeCharDevice) == 0
+
+	// if we've been given a file, don't automatically
+	// read from stdin.
+	// this happens if there is more than one argument
+	// or only one argument and its a file
+	if nullInput || !pipingStdin || len(args) > 1 || (len(args) > 0 && maybeFile(args[0])) {
+		return args
+	}
+
+	for _, arg := range args {
+		if arg == "-" {
+			return args
+		}
+	}
+	yqlib.GetLogger().Debugf("missing '-', adding it to the end")
+
+	// we're piping from stdin, but there's no '-' arg
+	// lets add one to the end
+	return append(args, "-")
+}
+
+func processArgs(originalArgs []string) (string, []string, error) {
+	expression := forceExpression
+	if expressionFile != "" {
+		expressionBytes, err := os.ReadFile(expressionFile)
+		if err != nil {
+			return "", nil, err
+		}
+		expression = string(expressionBytes)
+	}
+
+	args := processStdInArgs(originalArgs)
+	yqlib.GetLogger().Debugf("processed args: %v", args)
+	if expression == "" && len(args) > 0 && args[0] != "-" && !maybeFile(args[0]) {
+		yqlib.GetLogger().Debug("assuming expression is '%v'", args[0])
+		expression = args[0]
+		args = args[1:]
+	}
+	return expression, args, nil
+}

cmd/version.go

@@ -0,0 +1,49 @@
+package cmd
+
+import (
+	"fmt"
+	"strings"
+)
+
+// The git commit that was compiled. This will be filled in by the compiler.
+var (
+	GitCommit   string
+	GitDescribe string
+
+	// Version is main version number that is being run at the moment.
+	Version = "4.26.1"
+
+	// VersionPrerelease is a pre-release marker for the version. If this is "" (empty string)
+	// then it means that it is a final release. Otherwise, this is a pre-release
+	// such as "dev" (in development), "beta", "rc1", etc.
+	VersionPrerelease = ""
+)
+
+// ProductName is the name of the product
+const ProductName = "yq"
+
+// GetVersionDisplay composes the parts of the version in a way that's suitable
+// for displaying to humans.
+func GetVersionDisplay() string {
+	return fmt.Sprintf("yq (https://github.com/mikefarah/yq/) version %s\n", getHumanVersion())
+}
+
+func getHumanVersion() string {
+	version := Version
+	if GitDescribe != "" {
+		version = GitDescribe
+	}
+
+	release := VersionPrerelease
+	if release != "" {
+		if !strings.Contains(version, release) {
+			version += fmt.Sprintf("-%s", release)
+		}
+		if GitCommit != "" {
+			version += fmt.Sprintf(" (%s)", GitCommit)
+		}
+	}
+
+	// Strip off any single quotes added by the git information.
+	return strings.Replace(version, "'", "", -1)
+}

cmd/version_test.go

@@ -0,0 +1,51 @@
+package cmd
+
+import "testing"
+
+func TestGetVersionDisplay(t *testing.T) {
+	var expectedVersion = ProductName + " (https://github.com/mikefarah/yq/) version " + Version
+	if VersionPrerelease != "" {
+		expectedVersion = expectedVersion + "-" + VersionPrerelease
+	}
+	expectedVersion = expectedVersion + "\n"
+	tests := []struct {
+		name string
+		want string
+	}{
+		{
+			name: "Display Version",
+			want: expectedVersion,
+		},
+	}
+	for _, tt := range tests {
+		if got := GetVersionDisplay(); got != tt.want {
+			t.Errorf("%q. GetVersionDisplay() = %v, want %v", tt.name, got, tt.want)
+		}
+	}
+}
+
+func Test_getHumanVersion(t *testing.T) {
+	GitDescribe = "e42813d"
+	GitCommit = "e42813d+CHANGES"
+	var wanted string
+	if VersionPrerelease == "" {
+		wanted = GitDescribe
+	} else {
+		wanted = "e42813d-" + VersionPrerelease + " (e42813d+CHANGES)"
+	}
+
+	tests := []struct {
+		name string
+		want string
+	}{
+		{
+			name: "Git Variables defined",
+			want: wanted,
+		},
+	}
+	for _, tt := range tests {
+		if got := getHumanVersion(); got != tt.want {
+			t.Errorf("%q. getHumanVersion() = %v, want %v", tt.name, got, tt.want)
+		}
+	}
+}

data_navigator.go

@@ -1,50 +0,0 @@
-package main
-
-import (
-	// "fmt"
-	"log"
-	"strconv"
-)
-
-func write(context map[interface{}]interface{}, head string, tail []string, value interface{}) {
-	// e.g. if updating a.b.c, we need to get the 'b' map...
-	toUpdate := readMap(context, head, tail[0:len(tail)-1]).(map[interface{}]interface{})
-	//  and then set the 'c' key.
-	key := (tail[len(tail)-1])
-	toUpdate[key] = value
-}
-
-func readMap(context map[interface{}]interface{}, head string, tail []string) interface{} {
-	value := context[head]
-	if len(tail) > 0 {
-		return recurse(value, tail[0], tail[1:len(tail)])
-	}
-	return value
-}
-
-func recurse(value interface{}, head string, tail []string) interface{} {
-	switch value.(type) {
-	case []interface{}:
-		index, err := strconv.ParseInt(head, 10, 64)
-		if err != nil {
-			log.Fatalf("Error accessing array: %v", err)
-		}
-		return readArray(value.([]interface{}), index, tail)
-	case nil:
-		return nil
-	default:
-		return readMap(value.(map[interface{}]interface{}), head, tail)
-	}
-}
-
-func readArray(array []interface{}, head int64, tail []string) interface{} {
-	if head > int64(len(array)) {
-		return nil
-	}
-
-	value := array[head]
-	if len(tail) > 0 {
-		return recurse(value, tail[0], tail[1:len(tail)])
-	}
-	return value
-}

data_navigator_test.go

@@ -1,64 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"gopkg.in/yaml.v2"
-	"os"
-	"testing"
-)
-
-var rawData = `
-a: Easy!
-b:
-  c: 2
-  d: [3, 4]
-`
-
-var parsedData map[interface{}]interface{}
-
-func TestMain(m *testing.M) {
-	err := yaml.Unmarshal([]byte(rawData), &parsedData)
-	if err != nil {
-		fmt.Println("Error parsing yaml: %v", err)
-		os.Exit(1)
-	}
-
-	os.Exit(m.Run())
-}
-
-func TestReadMap_simple(t *testing.T) {
-	assertResult(t, 2, readMap(parsedData, "b", []string{"c"}))
-}
-
-func TestReadMap_key_doesnt_exist(t *testing.T) {
-	assertResult(t, nil, readMap(parsedData, "b.x.f", []string{"c"}))
-}
-
-func TestReadMap_with_array(t *testing.T) {
-	assertResult(t, 4, readMap(parsedData, "b", []string{"d", "1"}))
-}
-
-func TestReadMap_with_array_out_of_bounds(t *testing.T) {
-	assertResult(t, nil, readMap(parsedData, "b", []string{"d", "3"}))
-}
-
-func TestWrite_simple(t *testing.T) {
-
-	write(parsedData, "b", []string{"c"}, "4")
-
-	b := parsedData["b"].(map[interface{}]interface{})
-	assertResult(t, "4", b["c"].(string))
-}
-
-func assertResult(t *testing.T, expectedValue interface{}, actualValue interface{}) {
-	if expectedValue != actualValue {
-		t.Error("Expected <", expectedValue, "> but got <", actualValue, ">")
-	}
-}
-
-func assertResultWithContext(t *testing.T, expectedValue interface{}, actualValue interface{}, context interface{}) {
-	if expectedValue != actualValue {
-		t.Error(context)
-		t.Error(": expected <", expectedValue, "> but got <", actualValue, ">")
-	}
-}

debian/changelog

@@ -0,0 +1,210 @@
+yq (4.16.2) focal; urgency=medium
+
+  * Fixed with semicolon space issue
+  * Updating with documentation
+  * Added STDIN example to the top
+  * minor readme cleanup
+  * Help text tweak
+  * Fixed docker timeout - simplify docker builds
+  * New release with docker build fixes
+  * Updating to go 1.17 to fix CVE #944
+  * Fix a typo in root.go
+  * Skip the tests if the nocheck Debian build option is specified
+  * Fixed select bug (#958)
+  * Sped up explode operator
+  * Slight performance improvement to context.ChildContext
+  * Speed up multiply
+  * Update README with recently added / changed options
+  * Make deepMatch report in linear time
+  * Removed leadingContentPreProcessing flag - header preprocessing is stable
+  * Revert "Removed leadingContentPreProcessing flag - header preprocessing is stable"
+  * Keep flag, it is needed in corner cases
+  * Updated Readme
+  * Man page
+  * Fixed expression parsing bug #970
+  * Bumping go-lang, docker versions
+  * Added test release flow
+  * Updated github action release to generate man page
+  * Bumping version
+  * Removing no longer needed github action
+  * Added decoder op
+  * Fixed newline handling when decoding/encoding
+  * Fixed newline handling in encoder/decoder
+  * Can specify indent in encode ops
+  * Added group_by operator
+  * Added flatten operator
+  * Fixed flatten error message
+  * Improving docs
+  * Split printer
+  * Refactored command logic
+  * Fix JSON encoding removing null #985
+  * Fixed acceptance tests
+  * gitbook
+  * Update document generation script
+  * Updating README
+  * Updating release instructions
+  * github action no longer uses data1.yml
+  * Create dependabot.yml
+  * Bump actions/create-release from 1.0.0 to 1.1.4
+  * Bump actions/setup-go from 1 to 2.1.4
+  * Bump github.com/goccy/go-yaml from 1.8.9 to 1.9.4
+  * Bump github.com/jinzhu/copier from 0.2.8 to 0.3.2
+  * Bump github.com/fatih/color from 1.10.0 to 1.13.0
+  * Bump github.com/spf13/cobra from 1.1.3 to 1.2.1
+  * Update dependabot.yml
+  * Update go.yml
+  * add build check to PRs
+  * Include secure as part of build process
+  * Fixing bad label in github action
+  * fixed printer test
+  * remove leading content indicator
+  * Fixed header preprocessing!
+  * lint : define golangci configuration file
+  * Update check.sh
+  * Load file acceptance test
+  * Minor improvement on handling front matter
+  * Improved load doc
+  * feature: detect MANPATh and install there
+  * Update install-man-page.sh
+  * simplify prod stage, move version label to action
+  * add labels, quote some values
+  * enable errorlint linter
+  * Added errorlint to devtools
+  * Added key operator
+  * Added more tests
+  * Fixing comments
+  * Attempt to fix golint problem
+  * Include version query for tools
+  * Clean up errored file?
+  * enable misspell linter
+  * updated readme
+  * update Golangci version to v1.43.0
+  * gci linter
+  * Better merge array by key example
+  * Added credit for merge by array example
+  * Better formatting of merge arrays example
+  * Better merge example
+  * Add accessor for the yq logger instance (#1013)
+  * Fixed collect op when working with multiple nodes
+  * Added map, map_values
+  * Add support for Podman as well as Docker (#1026)
+  * Bump github.com/jinzhu/copier from 0.3.2 to 0.3.4 (#1027)
+  * Added csv, tsv output formats
+  * Added encoder tests
+  * Cleanup test
+  * Fixed docker permission issue #1014
+  * Recording release notes for next release
+  * Assignment op no longer clobbers anchor (#1029)
+  * Added sort_by operator
+  * Improved error message
+  * Improved tips and tricks
+  * Report while filename failed to parse #1030
+  * Added script for extracting checksums
+  * Improved extract-checksum.sh
+  * Bump github.com/spf13/cobra from 1.2.1 to 1.3.0 (#1039)
+  * enable more linters (#1043)
+  * Bump golang compiler #1037
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Tue, 21 Dec 2021 09:41:44 +0000
+
+yq (4.13.0) focal; urgency=medium
+
+  * New `with` operator for making multiple changes to a given path
+  * New `contains` operator, works like the `jq` equivalent
+  * Subtract operator now supports subtracting elements from arrays!
+  * Fixed Swapping values using variables #934
+  * Github Action now properly supports multiline output #936, thanks @pjxiao
+  * Fixed missing closing bracket validation #932
+  * Fix processing of hex numbers #929
+  * Fixed alternative and union operator issues #930
+  * Can now convert yaml to properties properties format (`-o=props`), See [docs](https://mikefarah.gitbook.io/yq/v/v4.x/usage/properties) for more info.
+  * Fixed document header/footer comment handling when merging (https://github.com/mikefarah/yq/issues/919)
+  * pretty print yaml 1.1 compatibility  (https://github.com/mikefarah/yq/issues/914)
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Thu, 16 Sep 2021 20:58:30 +0200
+
+yq (4.9.6) focal; urgency=medium
+
+  * Added darwin/arm64 build, thanks @alecthomas
+  * Incremented docker alpine base version, thanks @da6d6i7-bronga
+  * Bug fix: multine expression
+  * Bug fix: special character
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Tue, 29 Jun 2021 21:32:14 +0200
+
+yq (3.3.2) focal; urgency=medium
+
+  * Bug fix: existStatus bug (#459)
+  * Automatically makes a os temp directory if it does not exist (#461)
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Fri, 07 Aug 2020 18:53:01 +0200
+
+yq (3.3-0) focal; urgency=medium
+
+  * You can control string styles (quotes) using the new --style flag
+  * String values now always have quotes when outputting to json
+  * Negative array indices now traverse the array backwards
+  * Added a --stripComments flag to print yaml without any comments
+  * Bumped go to version 1.14
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Thu, 30 Apr 2020 20:45:44 +0200
+
+yq (3.1-2) eoan; urgency=medium
+
+  * Bug fix: yq 3 was removing empty inline-style objects and arrays (#355)
+  * Bug fix: Merge option returned different output when switching order of 
+    merging files(#347)
+  * Bug fix: Add new object to existing array object was failing in 3.1.1 (#361)
+  * Bug fix: yq 3 empty keys did not allow merging of values (#356)
+  * Bug fix: keys quoted during merge (#363)
+  * Bug fix: Correct length with wc -l (#362)
+  * Bug fix: Write to empty document removed path (#359)
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Mon, 24 Feb 2020 20:31:58 +0100
+
+yq (3.1-1) eoan; urgency=medium
+
+  * Keeps yaml comments and formatting, can specify yaml tags when updating.
+  * Handles anchors
+  * Can print out matching paths and values when splatting
+  * JSON output works for all commands
+  * Yaml files with multiple documents are printed out as one JSON 
+    document per line.
+  * Deep splat (**) to match arbitrary paths
+  * Update scripts file format has changed to be more powerful
+  * Reading and splatting, matching results are printed once per line
+  * Bugfixing
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Tue, 11 Feb 2020 22:18:24 +0100
+
+yq (2.2-1) bionic; urgency=medium
+
+  * Added Windows support for the "--inplace" command flag
+  * Prefix now supports arrays
+  * Add prefix command
+  * Bump Alpine version to 3.8
+  * Improved docker build process
+  * Lint fixes
+  * Build support for all linux architectures supported by gox
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Sat, 19 Jan 2019 15:50:47 +0100
+
+yq (2.1-0) bionic; urgency=medium
+
+  * Ability to read multiple documents in a single file
+  * Ability to append list items instead of overwriting
+
+ -- Roberto Mier Escandón <rmescandon@gmail.com>  Tue, 10 Jul 2018 14:02:42 +0200
+
+yq (2.0-0) bionic; urgency=medium
+
+  * Release 2.0.0
+
+ -- Roberto Mier Escandón <rmescandon@gmail.com>  Wed, 20 Jun 2018 10:29:53 +0200
+
+yq (1.15-0) bionic; urgency=medium
+
+  * Release 1.15
+
+ -- Roberto Mier Escandón <rmescandon@gmail.com>  Wed, 06 Jun 2018 11:32:03 +0200
+

debian/compat

@@ -0,0 +1 @@
+10

debian/control

@@ -0,0 +1,22 @@
+Source: yq
+Section: devel
+Priority: optional
+Maintainer: Roberto Mier Escandón <rmescandon@gmail.com>
+Build-Depends: debhelper (>=10),
+               golang-1.17-go,
+               pandoc,
+               rsync
+Standards-Version: 4.1.4
+Homepage: https://github.com/mikefarah/yq.git
+Vcs-Browser: https://github.com/mikefarah/yq.git
+Vcs-Git: https://github.com/mikefarah/yq.git
+XS-Go-Import-Path: github.com/mikefarah/yq
+XSBC-Original-Maintainer: Roberto Mier Escandón <rmescandon@gmail.com>
+
+Package: yq
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: lightweight and portable command-line YAML processor
+ .
+ The aim of the project is to be the 
+ [jq](https://github.com/stedolan/jq) or sed of yaml files.

debian/copyright

@@ -0,0 +1,24 @@
+Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: yq
+Source: https://github.com/mikefarah/yq.git
+
+Files: *
+Copyright: 2017 Mike Farah
+License: Expat
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+    .
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+    .
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.

debian/gbp.conf

@@ -0,0 +1,2 @@
+[DEFAULT]
+pristine-tar = True

debian/rules

@@ -0,0 +1,74 @@
+#!/usr/bin/make -f
+#
+# Copyright (C) 2018-2021 Roberto Mier Escandón <rmescandon@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+PROJECT := yq
+OWNER := mikefarah
+REPO := github.com
+
+export DH_OPTIONS
+export DH_GOPKG := ${REPO}/${OWNER}/${PROJECT}
+export GOROOT := /usr/local/go
+export GOPATH := ${CURDIR}/_build
+export GOBIN := ${GOPATH}/bin
+export PATH := ${GOROOT}/bin:${GOBIN}:${PATH}
+export GOCACHE := /tmp/gocache
+export GOFLAGS := -mod=vendor
+export GO111MODULE := on
+
+SRCDIR := ${GOPATH}/src/${DH_GOPKG}
+DESTDIR := ${CURDIR}/debian/${PROJECT}
+BINDIR := /usr/bin
+MANDIR := /usr/share/man/man1/
+ASSETSDIR := /usr/share/${PROJECT}
+
+%:
+	dh $@
+
+override_dh_auto_build:
+	mkdir -p ${SRCDIR}
+	mkdir -p ${GOBIN}
+	# copy project to local srcdir to build from there
+	rsync -avz --progress --exclude=_build --exclude=debian --exclude=tmp. --exclude=go.mod --exclude=docs . $(SRCDIR)
+	# build go code
+	( \
+		cd ${SRCDIR} && \
+		go install -buildmode=pie ./... \
+	)
+
+	# build man page
+	( \
+		cd ${SRCDIR} && \
+		./scripts/generate-man-page-md.sh && \
+		./scripts/generate-man-page.sh \
+	)
+	
+override_dh_auto_test:
+ifeq (,$(filter nocheck,$(DEB_BUILD_OPTIONS)))
+	(cd ${SRCDIR} && go test -v ./...)
+endif
+
+override_dh_auto_install:
+	cp ${GOBIN}/yq ${DESTDIR}/${BINDIR}
+	cp -f ${SRCDIR}/LICENSE ${DESTDIR}/${ASSETSDIR}
+	chmod a+x ${DESTDIR}/${BINDIR}/yq
+
+	# man
+	mkdir -p "${DESTDIR}"/"${MANDIR}"
+	cp "${SRCDIR}"/yq.1 "${DESTDIR}"/"${MANDIR}" \
+
+override_dh_auto_clean:
+	dh_clean
+	rm -rf ${CURDIR}/_build

debian/source/format

@@ -0,0 +1 @@
+3.0 (native)

debian/yq.dirs

@@ -0,0 +1,3 @@
+usr/bin
+usr/share/yq
+usr/share/man/man1

examples/array.yaml

@@ -0,0 +1,11 @@
+---
+- become: true
+  gather_facts: false
+  hosts: lalaland
+  name: "Apply smth"
+  roles:
+    - lala
+    - land
+  serial: 1
+- become: false
+  gather_facts: true

examples/bad.yaml

@@ -0,0 +1,8 @@
+b:
+  d: be gone
+  c: 2
+  e:
+    - name: Billy Bob # comment over here
+
+---
+[123123

examples/base64.txt

@@ -0,0 +1 @@
+bXkgc2VjcmV0IGNoaWxsaSByZWNpcGUgaXMuLi4u

examples/data1-no-comments.yaml

@@ -0,0 +1,4 @@
+a: simple
+b: [1, 2]
+c:
+  test: 1

examples/data1.yaml

@@ -0,0 +1,12 @@
+# --------------------------------------------------
+# It's a test with comment
+# --------------------------------------------------
+test:
+  - name: a
+  - name: b
+  - name: c
+groups:
+  - name: a
+  - name: b
+  - name: c
+  - name: c

examples/data2.yaml

@@ -0,0 +1,5 @@
+# --------------------------------------------------
+# It's a test with comment
+# --------------------------------------------------
+groups:
+  - name: d

examples/data3.yaml

@@ -0,0 +1,4 @@
+a: "simple" # just the best
+b: [1, 3]
+c:
+  test: 1

examples/empty.yaml

@@ -0,0 +1 @@
+# comment

examples/example.properties

@@ -0,0 +1,6 @@
+# comments on values appear
+person.name = Mike
+
+# comments on array values appear
+person.pets.0 = cat
+person.food.0 = pizza

examples/front-matter.yaml

@@ -0,0 +1,6 @@
+---
+a: apple
+b: bannana
+---
+hello there
+apples: great

examples/instruction_sample.yaml

@@ -0,0 +1,7 @@
+- command: update 
+  path: b.c
+  value:
+    #great 
+    things: frog # wow!
+- command: delete
+  path: b.d

examples/leading-seperator.yaml

@@ -0,0 +1,2 @@
+---
+a: test

examples/merge-anchor.yaml

@@ -0,0 +1,19 @@
+foo: &foo
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+
+bar: &bar
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+
+foobarList:
+  b: foobarList_b
+  <<: [*foo,*bar]
+  c: foobarList_c
+
+foobar:
+  c: foobar_c
+  <<: *foo
+  thing: foobar_thing

examples/mike.xml

@@ -0,0 +1,14 @@
+<!-- before cat -->
+<cat>
+	<!-- in cat before -->
+	<x>3<!-- multi
+line comment
+for x --></x>
+	<y>
+		<!-- in y before -->
+		<d><!-- in d before -->4<!-- in d after --></d>
+		<!-- in y after -->
+	</y>
+	<!-- in_cat_after -->
+</cat>
+<!-- after cat -->

examples/mike2.xml

@@ -0,0 +1,11 @@
+  <?xml version="1.0" encoding="UTF-8"?>
+  <!-- osm-->
+  <osm version="0.6" generator="CGImap 0.0.2">
+  <!-- bounds-->
+   <bounds minlat="54.0889580" minlon="12.2487570" maxlat="54.0913900" maxlon="12.2524800">
+   <!-- great -->
+   cool
+   </bounds>
+   <foo>ba2234r</foo>
+   <foo>bar2234233</foo>
+  </osm>

examples/multiline-text.yaml

@@ -0,0 +1,5 @@
+test: |
+  abcdefg    
+  hijklmno
+
+

examples/multiple_docs.yaml

@@ -0,0 +1,18 @@
+commonKey: first document
+a: Easy! as one two three
+b:
+  c: 2
+  d: [3, 4]
+  e:
+    - name: fred
+      value: 3
+    - name: sam
+      value: 4
+---
+commonKey: second document
+another:
+  document: here
+---
+commonKey: third document
+wow: 
+  - here is another

examples/multiple_docs_small.yaml

@@ -0,0 +1,7 @@
+a: Easy! as one two three
+---
+another:
+  document: here
+---
+- 1
+- 2

examples/numbered_keys.yml

@@ -0,0 +1,2 @@
+5:
+  6: camel!

examples/order.yaml

@@ -0,0 +1,2 @@
+version: 3
+application: MyApp

examples/order.yml

@@ -0,0 +1,6 @@
+version: '2'
+services:
+  test:
+    image: ubuntu:14.04
+    stdin_open: true
+    tty: true

examples/sample.json

@@ -0,0 +1 @@
+{"a":"Easy! as one two three","b":{"c":2,"d":[3,4],"e":[{"name":"fred","value":3},{"name":"sam","value":4}]},"ab":"must appear last"}

examples/sample.yaml

@@ -1,9 +1,11 @@
-a: Easy! as one two three
+# Some doc
+
+a: true
 b:
   c: 2
-  d: [3, 4]
+  d: [3, 4, 5]
   e:
     - name: fred
       value: 3
     - name: sam
-      value: 4
+      value: 4

examples/sample_array.yaml

@@ -0,0 +1 @@
+[1,2,3]

examples/sample_array_2.yaml

@@ -0,0 +1,2 @@
+- 4
+- 5

examples/sample_objects.csv

@@ -0,0 +1,3 @@
+name,numberOfCats,likesApples,height
+Gary,1,true,168.8
+Samantha's Rabbit,2,false,-188.8

examples/sample_text.yaml

@@ -0,0 +1 @@
+hi

examples/simple-anchor-exploded.yaml

@@ -0,0 +1,5 @@
+foo:
+  a: 1
+
+foobar: 
+  a: 1

examples/simple-anchor.yaml

@@ -0,0 +1,5 @@
+foo: &foo
+  a: 1
+
+foobar: 
+  <<: *foo

examples/small.properties

@@ -0,0 +1 @@
+this.is = a properties file

examples/small.xml

@@ -0,0 +1 @@
+<this>is some xml</this>

examples/thing.yml

@@ -0,0 +1,2 @@
+a: apple is included
+b: cool.

github-action/Dockerfile

@@ -0,0 +1,8 @@
+FROM mikefarah/yq:4
+
+COPY entrypoint.sh /entrypoint.sh
+
+# this seems to be the default user in github actions
+USER 1001
+
+ENTRYPOINT ["/entrypoint.sh"]

github-action/entrypoint.sh

@@ -0,0 +1,9 @@
+#!/bin/sh -l
+set -e
+echo "::debug::\$cmd: $1"
+RESULT=$(eval "$1")
+RESULT="${RESULT//'%'/'%25'}"
+RESULT="${RESULT//$'\n'/'%0A'}"
+RESULT="${RESULT//$'\r'/'%0D'}"
+echo "::debug::\$RESULT: $RESULT"
+echo ::set-output name=result::"$RESULT"

go.mod

@@ -0,0 +1,30 @@
+module github.com/mikefarah/yq/v4
+
+require (
+	github.com/a8m/envsubst v1.3.0
+	github.com/alecthomas/participle/v2 v2.0.0-beta.4
+	github.com/alecthomas/repr v0.1.0
+	github.com/elliotchance/orderedmap v1.4.0
+	github.com/fatih/color v1.13.0
+	github.com/goccy/go-json v0.9.10
+	github.com/goccy/go-yaml v1.9.5
+	github.com/jinzhu/copier v0.3.5
+	github.com/magiconair/properties v1.8.6
+	github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e
+	github.com/spf13/cobra v1.5.0
+	golang.org/x/net v0.0.0-20220708220712-1185a9018129
+	gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473
+	gopkg.in/yaml.v3 v3.0.1
+)
+
+require (
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/mattn/go-colorable v0.1.12 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	golang.org/x/sys v0.0.0-20220712014510-0a85c31ab51e // indirect
+	golang.org/x/text v0.3.7 // indirect
+	golang.org/x/xerrors v0.0.0-20220609144429-65e65417b02f // indirect
+)
+
+go 1.18

go.sum

@@ -0,0 +1,81 @@
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+gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473 h1:6D+BvnJ/j6e222UW8s2qTSe3wGBtvo0MbVQG/c5k8RE=
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+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

how-it-works.md

@@ -0,0 +1,129 @@
+# How it works
+
+In `yq` expressions are made up of operators and pipes. A context of nodes is passed through the expression and each operation takes the context as input and returns a new context as output. That output is piped in as input for the next operation in the expression. To begin with, the context is set to the first yaml document of the first yaml file (if processing in sequence using eval).
+
+Lets look at a couple of examples.
+
+## Simple assignment example
+
+Given a document like:
+
+```yaml
+a: cat
+b: dog
+```
+
+with an expression:
+
+```
+.a = .b
+```
+
+Like math expressions - operator precedence is important. 
+
+The `=` operator takes two arguments, a `lhs` expression, which in this case is `.a` and `rhs` expression which is `.b`. 
+
+It pipes the current, lets call it 'root' context through the `lhs` expression of `.a` to return the node 
+
+```yaml
+cat
+```
+
+Sidenote: this node holds not only its value 'cat', but comments and metadata too, including path and parent information.
+
+The `=` operator then pipes the 'root' context through the `rhs` expression of `.b` to return the node
+
+```yaml
+dog
+```
+
+Both sides have now been evaluated, so now the operator copies across the value from the RHS (`.b`) to the the LHS (`.a`), and it returns the now updated context:
+
+```yaml
+a: dog
+b: dog
+```
+
+
+## Complex assignment, operator precedence rules
+
+Just like math expressions - `yq` expressions have an order of precedence. The pipe `|` operator has a low order of precedence, so operators with higher precedence will get evaluated first. 
+
+Most of the time, this is intuitively what you'd want, for instance `.a = "cat" | .b = "dog"` is effectively: `(.a = "cat") | (.b = "dog")`.
+
+However, this is not always the case, particularly if you have a complex LHS or RHS expression, for instance if you want to select particular nodes to update. 
+
+Lets say you had:
+
+```yaml
+- name: bob
+  fruit: apple
+- name: sally
+  fruit: orange
+
+```
+
+Lets say you wanted to update the `sally` entry to have fruit: 'mango'. The _incorrect_ way to do that is:
+`.[] | select(.name == "sally") | .fruit = "mango"`.
+
+Because `|` has a low operator precedence, this will be evaluated (_incorrectly_) as : `(.[]) | (select(.name == "sally")) | (.fruit = "mango")`. What you'll see is only the updated segment returned:
+
+```yaml
+name: sally
+fruit: mango
+```
+
+To properly update this yaml, you will need to use brackets (think BODMAS from maths) and wrap the entire LHS:
+`(.[] | select(.name == "sally") | .fruit) = "mango"`
+
+
+Now that entire LHS expression is passed to the 'assign' (`=`) operator, and the yaml is correctly updated and returned:
+
+
+```yaml
+- name: bob
+  fruit: apple
+- name: sally
+  fruit: mango
+
+```
+
+## Relative update (e.g. `|=`)
+There is another form of the `=` operator which we call the relative form. It's very similar to `=` but with one key difference when evaluating the RHS expression.
+
+In the plain form, we pass in the 'root' level context to the RHS expression. In relative form, we pass in _each result of the LHS_ to the RHS expression. Let's go through an example.
+
+Given a document like:
+
+```yaml
+a: 1
+b: thing
+```
+
+with an expression:
+
+```
+.a |= . + 1
+```
+
+Similar to the `=` operator, `|=` takes two operands, the LHS and RHS.
+
+It pipes the current context (the whole document) through the LHS expression of `.a` to get the node value:
+
+```
+1
+```
+
+Now it pipes _that LHS context_ into the RHS expression `. + 1` (whereas in the `=` plain form it piped the original document context into the RHS) to yield:
+
+
+```
+2
+```
+
+The assignment operator then copies across the value from the RHS to the value on the LHS, and it returns the now updated 'root' context:
+
+```yaml
+a: 2
+b: thing
+```

mkdocs.yml

@@ -0,0 +1,7 @@
+docs_dir: mkdocs
+site_dir: docs
+site_name: Yq
+theme: 'material'
+repo_name: 'mikefarah/yq'
+repo_url: 'https://github.com/mikefarah/yq'
+

path_parser.go

@@ -1,55 +0,0 @@
-package main
-
-func parsePath(path string) []string {
-	return parsePathAccum([]string{}, path)
-}
-
-func parsePathAccum(paths []string, remaining string) []string {
-	head, tail := nextYamlPath(remaining)
-	if tail == "" {
-		return append(paths, head)
-	}
-	return parsePathAccum(append(paths, head), tail)
-}
-
-func nextYamlPath(path string) (pathElement string, remaining string) {
-	switch path[0] {
-	case '[':
-		// e.g [0].blah.cat -> we need to return "0" and "blah.cat"
-		return search(path[1:len(path)], []uint8{']'}, true)
-	case '"':
-		// e.g "a.b".blah.cat -> we need to return "a.b" and "blah.cat"
-		return search(path[1:len(path)], []uint8{'"'}, true)
-	default:
-		// e.g "a.blah.cat" -> return "a" and "blah.cat"
-		return search(path[0:len(path)], []uint8{'.', '['}, false)
-	}
-}
-
-func search(path string, matchingChars []uint8, skipNext bool) (pathElement string, remaining string) {
-	for i := 0; i < len(path); i++ {
-		var char = path[i]
-		if contains(matchingChars, char) {
-			var remainingStart = i + 1
-			if skipNext {
-				remainingStart = remainingStart + 1
-			} else if !skipNext && char != '.' {
-				remainingStart = i
-			}
-			if remainingStart > len(path) {
-				remainingStart = len(path)
-			}
-			return path[0:i], path[remainingStart:len(path)]
-		}
-	}
-	return path, ""
-}
-
-func contains(matchingChars []uint8, candidate uint8) bool {
-	for _, a := range matchingChars {
-		if a == candidate {
-			return true
-		}
-	}
-	return false
-}

path_parser_test.go

@@ -1,42 +0,0 @@
-package main
-
-import (
-	"testing"
-)
-
-var parsePathsTests = []struct {
-	path          string
-	expectedPaths []string
-}{
-	{"a.b", []string{"a", "b"}},
-	{"a.b[0]", []string{"a", "b", "0"}},
-}
-
-func testParsePath(t *testing.T) {
-	for _, tt := range parsePathsTests {
-		assertResultWithContext(t, tt.expectedPaths, parsePath(tt.path), tt)
-	}
-}
-
-var nextYamlPathTests = []struct {
-	path              string
-	expectedElement   string
-	expectedRemaining string
-}{
-	{"a.b", "a", "b"},
-	{"a", "a", ""},
-	{"a.b.c", "a", "b.c"},
-	{"\"a.b\".c", "a.b", "c"},
-	{"a.\"b.c\".d", "a", "\"b.c\".d"},
-	{"[1].a.d", "1", "a.d"},
-	{"a[0].c", "a", "[0].c"},
-	{"[0]", "0", ""},
-}
-
-func TestNextYamlPath(t *testing.T) {
-	for _, tt := range nextYamlPathTests {
-		var element, remaining = nextYamlPath(tt.path)
-		assertResultWithContext(t, tt.expectedElement, element, tt)
-		assertResultWithContext(t, tt.expectedRemaining, remaining, tt)
-	}
-}

pkg/yqlib/all_at_once_evaluator.go

@@ -0,0 +1,90 @@
+package yqlib
+
+import (
+	"container/list"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+// A yaml expression evaluator that runs the expression once against all files/nodes in memory.
+type Evaluator interface {
+	EvaluateFiles(expression string, filenames []string, printer Printer, leadingContentPreProcessing bool, decoder Decoder) error
+
+	// EvaluateNodes takes an expression and one or more yaml nodes, returning a list of matching candidate nodes
+	EvaluateNodes(expression string, nodes ...*yaml.Node) (*list.List, error)
+
+	// EvaluateCandidateNodes takes an expression and list of candidate nodes, returning a list of matching candidate nodes
+	EvaluateCandidateNodes(expression string, inputCandidateNodes *list.List) (*list.List, error)
+}
+
+type allAtOnceEvaluator struct {
+	treeNavigator DataTreeNavigator
+}
+
+func NewAllAtOnceEvaluator() Evaluator {
+	InitExpressionParser()
+	return &allAtOnceEvaluator{treeNavigator: NewDataTreeNavigator()}
+}
+
+func (e *allAtOnceEvaluator) EvaluateNodes(expression string, nodes ...*yaml.Node) (*list.List, error) {
+	inputCandidates := list.New()
+	for _, node := range nodes {
+		inputCandidates.PushBack(&CandidateNode{Node: node})
+	}
+	return e.EvaluateCandidateNodes(expression, inputCandidates)
+}
+
+func (e *allAtOnceEvaluator) EvaluateCandidateNodes(expression string, inputCandidates *list.List) (*list.List, error) {
+	node, err := ExpressionParser.ParseExpression(expression)
+	if err != nil {
+		return nil, err
+	}
+	context, err := e.treeNavigator.GetMatchingNodes(Context{MatchingNodes: inputCandidates}, node)
+	if err != nil {
+		return nil, err
+	}
+	return context.MatchingNodes, nil
+}
+
+func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string, printer Printer, leadingContentPreProcessing bool, decoder Decoder) error {
+	fileIndex := 0
+	firstFileLeadingContent := ""
+
+	var allDocuments = list.New()
+	for _, filename := range filenames {
+		reader, leadingContent, err := readStream(filename, fileIndex == 0 && leadingContentPreProcessing)
+		if err != nil {
+			return err
+		}
+
+		if fileIndex == 0 {
+			firstFileLeadingContent = leadingContent
+		}
+
+		fileDocuments, err := readDocuments(reader, filename, fileIndex, decoder)
+		if err != nil {
+			return err
+		}
+		allDocuments.PushBackList(fileDocuments)
+		fileIndex = fileIndex + 1
+	}
+
+	if allDocuments.Len() == 0 {
+		candidateNode := &CandidateNode{
+			Document:       0,
+			Filename:       "",
+			Node:           &yaml.Node{Kind: yaml.DocumentNode, Content: []*yaml.Node{{Tag: "!!null", Kind: yaml.ScalarNode}}},
+			FileIndex:      0,
+			LeadingContent: firstFileLeadingContent,
+		}
+		allDocuments.PushBack(candidateNode)
+	} else {
+		allDocuments.Front().Value.(*CandidateNode).LeadingContent = firstFileLeadingContent
+	}
+
+	matches, err := e.EvaluateCandidateNodes(expression, allDocuments)
+	if err != nil {
+		return err
+	}
+	return printer.PrintResults(matches)
+}

pkg/yqlib/all_at_once_evaluator_test.go

@@ -0,0 +1,40 @@
+package yqlib
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+var evaluateNodesScenario = []expressionScenario{
+	{
+		document:   `a: hello`,
+		expression: `.a`,
+		expected: []string{
+			"D0, P[a], (!!str)::hello\n",
+		},
+	},
+	{
+		document:   `a: hello`,
+		expression: `.`,
+		expected: []string{
+			"D0, P[], (doc)::a: hello\n",
+		},
+	},
+	{
+		document:   `- a: "yes"`,
+		expression: `.[] | has("a")`,
+		expected: []string{
+			"D0, P[0], (!!bool)::true\n",
+		},
+	},
+}
+
+func TestAllAtOnceEvaluateNodes(t *testing.T) {
+	var evaluator = NewAllAtOnceEvaluator()
+	for _, tt := range evaluateNodesScenario {
+		node := test.ParseData(tt.document)
+		list, _ := evaluator.EvaluateNodes(tt.expression, &node)
+		test.AssertResultComplex(t, tt.expected, resultsToString(t, list))
+	}
+}

pkg/yqlib/candidate_node.go

@@ -0,0 +1,189 @@
+package yqlib
+
+import (
+	"container/list"
+	"fmt"
+	"strings"
+
+	"github.com/jinzhu/copier"
+	yaml "gopkg.in/yaml.v3"
+)
+
+type CandidateNode struct {
+	Node   *yaml.Node     // the actual node
+	Parent *CandidateNode // parent node
+	Key    *yaml.Node     // node key, if this is a value from a map (or index in an array)
+
+	LeadingContent  string
+	TrailingContent string
+
+	Path      []interface{} /// the path we took to get to this node
+	Document  uint          // the document index of this node
+	Filename  string
+	FileIndex int
+	// when performing op against all nodes given, this will treat all the nodes as one
+	// (e.g. top level cross document merge). This property does not propagate to child nodes.
+	EvaluateTogether bool
+	IsMapKey         bool
+}
+
+func (n *CandidateNode) GetKey() string {
+	keyPrefix := ""
+	if n.IsMapKey {
+		keyPrefix = "key-"
+	}
+	return fmt.Sprintf("%v%v - %v", keyPrefix, n.Document, n.Path)
+}
+
+func (n *CandidateNode) GetNiceTag() string {
+	return unwrapDoc(n.Node).Tag
+}
+
+func (n *CandidateNode) GetNicePath() string {
+	if n.Path != nil && len(n.Path) >= 0 {
+		pathStr := make([]string, len(n.Path))
+		for i, v := range n.Path {
+			pathStr[i] = fmt.Sprintf("%v", v)
+		}
+		return strings.Join(pathStr, ".")
+	}
+	return ""
+}
+
+func (n *CandidateNode) AsList() *list.List {
+	elMap := list.New()
+	elMap.PushBack(n)
+	return elMap
+}
+
+func (n *CandidateNode) CreateChildInMap(key *yaml.Node, node *yaml.Node) *CandidateNode {
+	var value interface{}
+	if key != nil {
+		value = key.Value
+	}
+	return &CandidateNode{
+		Node:      node,
+		Path:      n.createChildPath(value),
+		Parent:    n,
+		Key:       key,
+		Document:  n.Document,
+		Filename:  n.Filename,
+		FileIndex: n.FileIndex,
+	}
+}
+
+func (n *CandidateNode) CreateChildInArray(index int, node *yaml.Node) *CandidateNode {
+	return &CandidateNode{
+		Node:      node,
+		Path:      n.createChildPath(index),
+		Parent:    n,
+		Key:       &yaml.Node{Kind: yaml.ScalarNode, Value: fmt.Sprintf("%v", index), Tag: "!!int"},
+		Document:  n.Document,
+		Filename:  n.Filename,
+		FileIndex: n.FileIndex,
+	}
+}
+
+func (n *CandidateNode) CreateReplacement(node *yaml.Node) *CandidateNode {
+	return &CandidateNode{
+		Node:      node,
+		Path:      n.createChildPath(nil),
+		Parent:    n.Parent,
+		Key:       n.Key,
+		IsMapKey:  n.IsMapKey,
+		Document:  n.Document,
+		Filename:  n.Filename,
+		FileIndex: n.FileIndex,
+	}
+}
+
+func (n *CandidateNode) CreateReplacementWithDocWrappers(node *yaml.Node) *CandidateNode {
+	replacement := n.CreateReplacement(node)
+	replacement.LeadingContent = n.LeadingContent
+	replacement.TrailingContent = n.TrailingContent
+	return replacement
+}
+
+func (n *CandidateNode) createChildPath(path interface{}) []interface{} {
+	if path == nil {
+		newPath := make([]interface{}, len(n.Path))
+		copy(newPath, n.Path)
+		return newPath
+	}
+
+	//don't use append as they may actually modify the path of the orignal node!
+	newPath := make([]interface{}, len(n.Path)+1)
+	copy(newPath, n.Path)
+	newPath[len(n.Path)] = path
+	return newPath
+}
+
+func (n *CandidateNode) Copy() (*CandidateNode, error) {
+	clone := &CandidateNode{}
+	err := copier.Copy(clone, n)
+	if err != nil {
+		return nil, err
+	}
+	clone.Node = deepClone(n.Node)
+	return clone, nil
+}
+
+// updates this candidate from the given candidate node
+func (n *CandidateNode) UpdateFrom(other *CandidateNode, prefs assignPreferences) {
+
+	// if this is an empty map or empty array, use the style of other node.
+	if (n.Node.Kind != yaml.ScalarNode && len(n.Node.Content) == 0) ||
+		// if the tag has changed (e.g. from str to bool)
+		(guessTagFromCustomType(n.Node) != guessTagFromCustomType(other.Node)) {
+		n.Node.Style = other.Node.Style
+	}
+
+	n.Node.Content = deepCloneContent(other.Node.Content)
+	n.Node.Kind = other.Node.Kind
+	n.Node.Value = other.Node.Value
+
+	n.UpdateAttributesFrom(other, prefs)
+
+}
+
+func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode, prefs assignPreferences) {
+	log.Debug("UpdateAttributesFrom: n: %v other: %v", n.GetKey(), other.GetKey())
+	if n.Node.Kind != other.Node.Kind {
+		// clear out the contents when switching to a different type
+		// e.g. map to array
+		n.Node.Content = make([]*yaml.Node, 0)
+		n.Node.Value = ""
+	}
+	n.Node.Kind = other.Node.Kind
+
+	// don't clobber custom tags...
+	if strings.HasPrefix(n.Node.Tag, "!!") || n.Node.Tag == "" {
+		n.Node.Tag = other.Node.Tag
+	}
+
+	n.Node.Alias = other.Node.Alias
+
+	if !prefs.DontOverWriteAnchor {
+		n.Node.Anchor = other.Node.Anchor
+	}
+
+	// merge will pickup the style of the new thing
+	// when autocreating nodes
+
+	if n.Node.Style == 0 {
+		n.Node.Style = other.Node.Style
+	}
+
+	if other.Node.FootComment != "" {
+		n.Node.FootComment = other.Node.FootComment
+	}
+	if other.TrailingContent != "" {
+		n.TrailingContent = other.TrailingContent
+	}
+	if other.Node.HeadComment != "" {
+		n.Node.HeadComment = other.Node.HeadComment
+	}
+	if other.Node.LineComment != "" {
+		n.Node.LineComment = other.Node.LineComment
+	}
+}

pkg/yqlib/color_print.go

@@ -0,0 +1,61 @@
+package yqlib
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/fatih/color"
+	"github.com/goccy/go-yaml/lexer"
+	"github.com/goccy/go-yaml/printer"
+)
+
+// Thanks @risentveber!
+
+const escape = "\x1b"
+
+func format(attr color.Attribute) string {
+	return fmt.Sprintf("%s[%dm", escape, attr)
+}
+
+func colorizeAndPrint(yamlBytes []byte, writer io.Writer) error {
+	tokens := lexer.Tokenize(string(yamlBytes))
+	var p printer.Printer
+	p.Bool = func() *printer.Property {
+		return &printer.Property{
+			Prefix: format(color.FgHiMagenta),
+			Suffix: format(color.Reset),
+		}
+	}
+	p.Number = func() *printer.Property {
+		return &printer.Property{
+			Prefix: format(color.FgHiMagenta),
+			Suffix: format(color.Reset),
+		}
+	}
+	p.MapKey = func() *printer.Property {
+		return &printer.Property{
+			Prefix: format(color.FgCyan),
+			Suffix: format(color.Reset),
+		}
+	}
+	p.Anchor = func() *printer.Property {
+		return &printer.Property{
+			Prefix: format(color.FgHiYellow),
+			Suffix: format(color.Reset),
+		}
+	}
+	p.Alias = func() *printer.Property {
+		return &printer.Property{
+			Prefix: format(color.FgHiYellow),
+			Suffix: format(color.Reset),
+		}
+	}
+	p.String = func() *printer.Property {
+		return &printer.Property{
+			Prefix: format(color.FgGreen),
+			Suffix: format(color.Reset),
+		}
+	}
+	_, err := writer.Write([]byte(p.PrintTokens(tokens) + "\n"))
+	return err
+}

pkg/yqlib/compare_operators.go

@@ -0,0 +1,133 @@
+package yqlib
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+type compareTypePref struct {
+	OrEqual bool
+	Greater bool
+}
+
+func compareOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
+	log.Debugf("-- compareOperator")
+	prefs := expressionNode.Operation.Preferences.(compareTypePref)
+	return crossFunction(d, context.ReadOnlyClone(), expressionNode, compare(prefs), true)
+}
+
+func compare(prefs compareTypePref) func(d *dataTreeNavigator, context Context, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
+	return func(d *dataTreeNavigator, context Context, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
+		log.Debugf("-- compare cross function")
+		if lhs == nil && rhs == nil {
+			owner := &CandidateNode{}
+			return createBooleanCandidate(owner, prefs.OrEqual), nil
+		} else if lhs == nil {
+			log.Debugf("lhs nil, but rhs is not")
+			return createBooleanCandidate(rhs, false), nil
+		} else if rhs == nil {
+			log.Debugf("rhs nil, but rhs is not")
+			return createBooleanCandidate(lhs, false), nil
+		}
+
+		lhs.Node = unwrapDoc(lhs.Node)
+		rhs.Node = unwrapDoc(rhs.Node)
+
+		switch lhs.Node.Kind {
+		case yaml.MappingNode:
+			return nil, fmt.Errorf("maps not yet supported for comparison")
+		case yaml.SequenceNode:
+			return nil, fmt.Errorf("arrays not yet supported for comparison")
+		default:
+			if rhs.Node.Kind != yaml.ScalarNode {
+				return nil, fmt.Errorf("%v (%v) cannot be subtracted from %v", rhs.Node.Tag, rhs.Path, lhs.Node.Tag)
+			}
+			target := lhs.CreateReplacement(&yaml.Node{})
+			boolV, err := compareScalars(context, prefs, lhs.Node, rhs.Node)
+
+			return createBooleanCandidate(target, boolV), err
+		}
+	}
+}
+
+func compareDateTime(layout string, prefs compareTypePref, lhs *yaml.Node, rhs *yaml.Node) (bool, error) {
+	lhsTime, err := time.Parse(layout, lhs.Value)
+	if err != nil {
+		return false, err
+	}
+
+	rhsTime, err := time.Parse(layout, rhs.Value)
+	if err != nil {
+		return false, err
+	}
+
+	if prefs.OrEqual && lhsTime.Equal(rhsTime) {
+		return true, nil
+	}
+	if prefs.Greater {
+		return lhsTime.After(rhsTime), nil
+	}
+	return lhsTime.Before(rhsTime), nil
+
+}
+
+func compareScalars(context Context, prefs compareTypePref, lhs *yaml.Node, rhs *yaml.Node) (bool, error) {
+	lhsTag := guessTagFromCustomType(lhs)
+	rhsTag := guessTagFromCustomType(rhs)
+
+	isDateTime := lhs.Tag == "!!timestamp"
+	// if the lhs is a string, it might be a timestamp in a custom format.
+	if lhsTag == "!!str" && context.GetDateTimeLayout() != time.RFC3339 {
+		_, err := time.Parse(context.GetDateTimeLayout(), lhs.Value)
+		isDateTime = err == nil
+	}
+	if isDateTime {
+		return compareDateTime(context.GetDateTimeLayout(), prefs, lhs, rhs)
+	} else if lhsTag == "!!int" && rhsTag == "!!int" {
+		_, lhsNum, err := parseInt64(lhs.Value)
+		if err != nil {
+			return false, err
+		}
+		_, rhsNum, err := parseInt64(rhs.Value)
+		if err != nil {
+			return false, err
+		}
+
+		if prefs.OrEqual && lhsNum == rhsNum {
+			return true, nil
+		}
+		if prefs.Greater {
+			return lhsNum > rhsNum, nil
+		}
+		return lhsNum < rhsNum, nil
+	} else if (lhsTag == "!!int" || lhsTag == "!!float") && (rhsTag == "!!int" || rhsTag == "!!float") {
+		lhsNum, err := strconv.ParseFloat(lhs.Value, 64)
+		if err != nil {
+			return false, err
+		}
+		rhsNum, err := strconv.ParseFloat(rhs.Value, 64)
+		if err != nil {
+			return false, err
+		}
+		if prefs.OrEqual && lhsNum == rhsNum {
+			return true, nil
+		}
+		if prefs.Greater {
+			return lhsNum > rhsNum, nil
+		}
+		return lhsNum < rhsNum, nil
+	} else if lhsTag == "!!str" && rhsTag == "!!str" {
+		if prefs.OrEqual && lhs.Value == rhs.Value {
+			return true, nil
+		}
+		if prefs.Greater {
+			return lhs.Value > rhs.Value, nil
+		}
+		return lhs.Value < rhs.Value, nil
+	}
+
+	return false, fmt.Errorf("%v not yet supported for comparison", lhs.Tag)
+}

pkg/yqlib/compare_operators_test.go

@@ -0,0 +1,371 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var compareOperatorScenarios = []expressionScenario{
+	// ints, not equal
+	{
+		description: "Compare numbers (>)",
+		document:    "a: 5\nb: 4",
+		expression:  ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5\nb: 4",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:     true,
+		description: "Compare integers (>=)",
+		document:    "a: 5\nb: 4",
+		expression:  ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5\nb: 4",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+
+	// ints, equal
+	{
+		skipDoc:     true,
+		description: "Compare equal numbers (>)",
+		document:    "a: 5\nb: 5",
+		expression:  ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5\nb: 5",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		description: "Compare equal numbers (>=)",
+		document:    "a: 5\nb: 5",
+		expression:  ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5\nb: 5",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+
+	// floats, not equal
+	{
+		skipDoc:    true,
+		document:   "a: 5.2\nb: 4.1",
+		expression: ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5.2\nb: 4.1",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5.2\nb: 4.1",
+		expression: ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5.5\nb: 4.1",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+
+	// floats, equal
+	{
+		skipDoc:    true,
+		document:   "a: 5.5\nb: 5.5",
+		expression: ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5.5\nb: 5.5",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5.1\nb: 5.1",
+		expression: ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 5.1\nb: 5.1",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+
+	// strings, not equal
+	{
+		description:    "Compare strings",
+		subdescription: "Compares strings by their bytecode.",
+		document:       "a: zoo\nb: apple",
+		expression:     ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: zoo\nb: apple",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: zoo\nb: apple",
+		expression: ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: zoo\nb: apple",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+
+	// strings, equal
+	{
+		skipDoc:    true,
+		document:   "a: cat\nb: cat",
+		expression: ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: cat\nb: cat",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: cat\nb: cat",
+		expression: ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: cat\nb: cat",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+
+	// datetime, not equal
+	{
+		description:    "Compare date times",
+		subdescription: "You can compare date times. Assumes RFC3339 date time format, see [date-time operators](https://mikefarah.gitbook.io/yq/operators/date-time-operators) for more information.",
+		document:       "a: 2021-01-01T03:10:00Z\nb: 2020-01-01T03:10:00Z",
+		expression:     ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2020-01-01T03:10:00Z",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2020-01-01T03:10:00Z",
+		expression: ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2020-01-01T03:10:00Z",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+
+	// datetime, equal
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2021-01-01T03:10:00Z",
+		expression: ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2021-01-01T03:10:00Z",
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2021-01-01T03:10:00Z",
+		expression: ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: 2021-01-01T03:10:00Z\nb: 2021-01-01T03:10:00Z",
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::true\n",
+		},
+	},
+	// both null
+	{
+		description: "Both sides are null: > is false",
+		expression:  ".a > .b",
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		description: "Both sides are null: >= is true",
+		expression:  ".a >= .b",
+		expected: []string{
+			"D0, P[], (!!bool)::true\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[], (!!bool)::true\n",
+		},
+	},
+
+	// one null
+	{
+		skipDoc:     true,
+		description: "One side is null: > is false",
+		document:    `a: 5`,
+		expression:  ".a > .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `a: 5`,
+		expression: ".a < .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:     true,
+		description: "One side is null: >= is false",
+		document:    `a: 5`,
+		expression:  ".a >= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `a: 5`,
+		expression: ".a <= .b",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `a: 5`,
+		expression: ".b <= .a",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `a: 5`,
+		expression: ".b < .a",
+		expected: []string{
+			"D0, P[a], (!!bool)::false\n",
+		},
+	},
+}
+
+func TestCompareOperatorScenarios(t *testing.T) {
+	for _, tt := range compareOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentOperatorScenarios(t, "compare", compareOperatorScenarios)
+}

pkg/yqlib/context.go

@@ -0,0 +1,122 @@
+package yqlib
+
+import (
+	"container/list"
+	"fmt"
+	"time"
+
+	"github.com/jinzhu/copier"
+	logging "gopkg.in/op/go-logging.v1"
+)
+
+type Context struct {
+	MatchingNodes  *list.List
+	Variables      map[string]*list.List
+	DontAutoCreate bool
+	datetimeLayout string
+}
+
+func (n *Context) SingleReadonlyChildContext(candidate *CandidateNode) Context {
+	list := list.New()
+	list.PushBack(candidate)
+	newContext := n.ChildContext(list)
+	newContext.DontAutoCreate = true
+	return newContext
+}
+
+func (n *Context) SingleChildContext(candidate *CandidateNode) Context {
+	list := list.New()
+	list.PushBack(candidate)
+	return n.ChildContext(list)
+}
+
+func (n *Context) SetDateTimeLayout(newDateTimeLayout string) {
+	n.datetimeLayout = newDateTimeLayout
+}
+
+func (n *Context) GetDateTimeLayout() string {
+	if n.datetimeLayout != "" {
+		return n.datetimeLayout
+	}
+	return time.RFC3339
+}
+
+func (n *Context) GetVariable(name string) *list.List {
+	if n.Variables == nil {
+		return nil
+	}
+	return n.Variables[name]
+}
+
+func (n *Context) SetVariable(name string, value *list.List) {
+	if n.Variables == nil {
+		n.Variables = make(map[string]*list.List)
+	}
+	n.Variables[name] = value
+}
+
+func (n *Context) ChildContext(results *list.List) Context {
+	clone := Context{DontAutoCreate: n.DontAutoCreate, datetimeLayout: n.datetimeLayout}
+	clone.Variables = make(map[string]*list.List)
+	if len(n.Variables) > 0 {
+		err := copier.Copy(&clone.Variables, n.Variables)
+		if err != nil {
+			log.Error("Error cloning context :(")
+			panic(err)
+		}
+	}
+	clone.MatchingNodes = results
+	return clone
+}
+
+func (n *Context) ToString() string {
+	if !log.IsEnabledFor(logging.DEBUG) {
+		return ""
+	}
+	result := fmt.Sprintf("Context\nDontAutoCreate: %v\n", n.DontAutoCreate)
+	return result + NodesToString(n.MatchingNodes)
+}
+
+func (n *Context) DeepClone() Context {
+	clone := Context{}
+	err := copier.Copy(&clone, n)
+	// copier doesn't do lists properly for some reason
+	clone.MatchingNodes = list.New()
+	for el := n.MatchingNodes.Front(); el != nil; el = el.Next() {
+		clonedNode, err := el.Value.(*CandidateNode).Copy()
+		if err != nil {
+			log.Error("Error cloning context :(")
+			panic(err)
+		}
+		clone.MatchingNodes.PushBack(clonedNode)
+	}
+
+	if err != nil {
+		log.Error("Error cloning context :(")
+		panic(err)
+	}
+	return clone
+}
+
+func (n *Context) Clone() Context {
+	clone := Context{}
+	err := copier.Copy(&clone, n)
+
+	if err != nil {
+		log.Error("Error cloning context :(")
+		panic(err)
+	}
+	return clone
+}
+
+func (n *Context) ReadOnlyClone() Context {
+	clone := n.Clone()
+	clone.DontAutoCreate = true
+	return clone
+}
+
+func (n *Context) WritableClone() Context {
+	clone := n.Clone()
+	clone.DontAutoCreate = false
+	return clone
+}

pkg/yqlib/csv_test.go

@@ -0,0 +1,273 @@
+package yqlib
+
+import (
+	"bufio"
+	"fmt"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+const csvSimple = `name,numberOfCats,likesApples,height
+Gary,1,true,168.8
+Samantha's Rabbit,2,false,-188.8
+`
+
+const expectedUpdatedSimpleCsv = `name,numberOfCats,likesApples,height
+Gary,3,true,168.8
+Samantha's Rabbit,2,false,-188.8
+`
+
+const csvSimpleShort = `Name,Number of Cats
+Gary,1
+Samantha's Rabbit,2
+`
+
+const tsvSimple = `name	numberOfCats	likesApples	height
+Gary	1	true	168.8
+Samantha's Rabbit	2	false	-188.8
+`
+
+const expectedYamlFromCSV = `- name: Gary
+  numberOfCats: 1
+  likesApples: true
+  height: 168.8
+- name: Samantha's Rabbit
+  numberOfCats: 2
+  likesApples: false
+  height: -188.8
+`
+
+const expectedYamlFromCSVMissingData = `- name: Gary
+  numberOfCats: 1
+  height: 168.8
+- name: Samantha's Rabbit
+  height: -188.8
+  likesApples: false
+`
+
+const csvSimpleMissingData = `name,numberOfCats,height
+Gary,1,168.8
+Samantha's Rabbit,,-188.8
+`
+
+const csvTestSimpleYaml = `- [i, like, csv]
+- [because, excel, is, cool]`
+
+const expectedSimpleCsv = `i,like,csv
+because,excel,is,cool
+`
+
+const tsvTestExpectedSimpleCsv = `i	like	csv
+because	excel	is	cool
+`
+
+var csvScenarios = []formatScenario{
+	{
+		description:  "Encode CSV simple",
+		input:        csvTestSimpleYaml,
+		expected:     expectedSimpleCsv,
+		scenarioType: "encode-csv",
+	},
+	{
+		description:  "Encode TSV simple",
+		input:        csvTestSimpleYaml,
+		expected:     tsvTestExpectedSimpleCsv,
+		scenarioType: "encode-tsv",
+	},
+	{
+		description:  "Encode Empty",
+		skipDoc:      true,
+		input:        `[]`,
+		expected:     "",
+		scenarioType: "encode-csv",
+	},
+	{
+		description:  "Comma in value",
+		skipDoc:      true,
+		input:        `["comma, in, value", things]`,
+		expected:     "\"comma, in, value\",things\n",
+		scenarioType: "encode-csv",
+	},
+	{
+		description:  "Encode array of objects to csv",
+		input:        expectedYamlFromCSV,
+		expected:     csvSimple,
+		scenarioType: "encode-csv",
+	},
+	{
+		description:    "Encode array of objects to custom csv format",
+		subdescription: "Add the header row manually, then the we convert each object into an array of values - resulting in an array of arrays. Pick the columns and call the header whatever you like.",
+		input:          expectedYamlFromCSV,
+		expected:       csvSimpleShort,
+		expression:     `[["Name", "Number of Cats"]] +  [.[] | [.name, .numberOfCats ]]`,
+		scenarioType:   "encode-csv",
+	},
+	{
+		description:    "Encode array of objects to csv - missing fields behaviour",
+		subdescription: "First entry is used to determine the headers, and it is missing 'likesApples', so it is not included in the csv. Second entry does not have 'numberOfCats' so that is blank",
+		input:          expectedYamlFromCSVMissingData,
+		expected:       csvSimpleMissingData,
+		scenarioType:   "encode-csv",
+	},
+	{
+		description:    "Parse CSV into an array of objects",
+		subdescription: "First row is assumed to be the header row.",
+		input:          csvSimple,
+		expected:       expectedYamlFromCSV,
+		scenarioType:   "decode-csv-object",
+	},
+	{
+		description:    "Parse TSV into an array of objects",
+		subdescription: "First row is assumed to be the header row.",
+		input:          tsvSimple,
+		expected:       expectedYamlFromCSV,
+		scenarioType:   "decode-tsv-object",
+	},
+	{
+		description:  "Round trip",
+		input:        csvSimple,
+		expected:     expectedUpdatedSimpleCsv,
+		expression:   `(.[] | select(.name == "Gary") | .numberOfCats) = 3`,
+		scenarioType: "roundtrip-csv",
+	},
+}
+
+func testCSVScenario(t *testing.T, s formatScenario) {
+	switch s.scenarioType {
+	case "encode-csv":
+		test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewYamlDecoder(), NewCsvEncoder(',')), s.description)
+	case "encode-tsv":
+		test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewYamlDecoder(), NewCsvEncoder('\t')), s.description)
+	case "decode-csv-object":
+		test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewCSVObjectDecoder(','), NewYamlEncoder(2, false, true, true)), s.description)
+	case "decode-tsv-object":
+		test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewCSVObjectDecoder('\t'), NewYamlEncoder(2, false, true, true)), s.description)
+	case "roundtrip-csv":
+		test.AssertResultWithContext(t, s.expected, processFormatScenario(s, NewCSVObjectDecoder(','), NewCsvEncoder(',')), s.description)
+	default:
+		panic(fmt.Sprintf("unhandled scenario type %q", s.scenarioType))
+	}
+}
+
+func documentCSVDecodeObjectScenario(t *testing.T, w *bufio.Writer, s formatScenario, formatType string) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, fmt.Sprintf("Given a sample.%v file of:\n", formatType))
+	writeOrPanic(w, fmt.Sprintf("```%v\n%v\n```\n", formatType, s.input))
+
+	writeOrPanic(w, "then\n")
+	writeOrPanic(w, fmt.Sprintf("```bash\nyq -p=%v sample.%v\n```\n", formatType, formatType))
+	writeOrPanic(w, "will output\n")
+
+	separator := ','
+	if formatType == "tsv" {
+		separator = '\t'
+	}
+
+	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n",
+		processFormatScenario(s, NewCSVObjectDecoder(separator), NewYamlEncoder(s.indent, false, true, true))),
+	)
+}
+
+func documentCSVEncodeScenario(w *bufio.Writer, s formatScenario, formatType string) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, "Given a sample.yml file of:\n")
+	writeOrPanic(w, fmt.Sprintf("```yaml\n%v\n```\n", s.input))
+
+	writeOrPanic(w, "then\n")
+
+	expression := s.expression
+
+	if expression != "" {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -o=%v '%v' sample.yml\n```\n", formatType, expression))
+	} else {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -o=%v sample.yml\n```\n", formatType))
+	}
+	writeOrPanic(w, "will output\n")
+
+	separator := ','
+	if formatType == "tsv" {
+		separator = '\t'
+	}
+
+	writeOrPanic(w, fmt.Sprintf("```%v\n%v```\n\n", formatType,
+		processFormatScenario(s, NewYamlDecoder(), NewCsvEncoder(separator))),
+	)
+}
+
+func documentCSVRoundTripScenario(w *bufio.Writer, s formatScenario, formatType string) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, fmt.Sprintf("Given a sample.%v file of:\n", formatType))
+	writeOrPanic(w, fmt.Sprintf("```%v\n%v\n```\n", formatType, s.input))
+
+	writeOrPanic(w, "then\n")
+
+	expression := s.expression
+
+	if expression != "" {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -p=%v -o=%v '%v' sample.%v\n```\n", formatType, formatType, expression, formatType))
+	} else {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -p=%v -o=%v sample.%v\n```\n", formatType, formatType, formatType))
+	}
+	writeOrPanic(w, "will output\n")
+
+	separator := ','
+	if formatType == "tsv" {
+		separator = '\t'
+	}
+
+	writeOrPanic(w, fmt.Sprintf("```%v\n%v```\n\n", formatType,
+		processFormatScenario(s, NewCSVObjectDecoder(separator), NewCsvEncoder(separator))),
+	)
+}
+
+func documentCSVScenario(t *testing.T, w *bufio.Writer, i interface{}) {
+	s := i.(formatScenario)
+	if s.skipDoc {
+		return
+	}
+	switch s.scenarioType {
+	case "encode-csv":
+		documentCSVEncodeScenario(w, s, "csv")
+	case "encode-tsv":
+		documentCSVEncodeScenario(w, s, "tsv")
+	case "decode-csv-object":
+		documentCSVDecodeObjectScenario(t, w, s, "csv")
+	case "decode-tsv-object":
+		documentCSVDecodeObjectScenario(t, w, s, "tsv")
+	case "roundtrip-csv":
+		documentCSVRoundTripScenario(w, s, "csv")
+
+	default:
+		panic(fmt.Sprintf("unhandled scenario type %q", s.scenarioType))
+	}
+}
+
+func TestCSVScenarios(t *testing.T) {
+	for _, tt := range csvScenarios {
+		testCSVScenario(t, tt)
+	}
+	genericScenarios := make([]interface{}, len(csvScenarios))
+	for i, s := range csvScenarios {
+		genericScenarios[i] = s
+	}
+	documentScenarios(t, "usage", "csv-tsv", genericScenarios, documentCSVScenario)
+}