mirror of https://github.com/mikefarah/yq.git
76 lines
873 B
Markdown
76 lines
873 B
Markdown
# Alternative (Default value)
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This operator is used to provide alternative (or default) values when a particular expression is either null or false.
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## LHS is defined
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Given a sample.yml file of:
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```yaml
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a: bridge
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```
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then
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```bash
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yq '.a // "hello"' sample.yml
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```
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will output
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```yaml
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bridge
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```
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## LHS is not defined
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Given a sample.yml file of:
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```yaml
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{}
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```
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then
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```bash
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yq '.a // "hello"' sample.yml
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```
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will output
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```yaml
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hello
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```
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## LHS is null
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Given a sample.yml file of:
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```yaml
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a: ~
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```
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then
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```bash
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yq '.a // "hello"' sample.yml
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```
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will output
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```yaml
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hello
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```
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## LHS is false
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Given a sample.yml file of:
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```yaml
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a: false
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```
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then
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```bash
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yq '.a // "hello"' sample.yml
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```
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will output
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```yaml
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hello
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```
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## RHS is an expression
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Given a sample.yml file of:
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```yaml
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a: false
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b: cat
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```
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then
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```bash
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yq '.a // .b' sample.yml
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```
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will output
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```yaml
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cat
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```
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