add help description

README.md

@@ -1,4 +1,4 @@
-# yq 
+# yq
 
 [![Build Status](https://travis-ci.org/mikefarah/yq.svg?branch=master)](https://travis-ci.org/mikefarah/yq)  ![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)
 
@@ -82,6 +82,8 @@ docker run -it -v ${PWD}:/workdir mikefarah/yq sh
 Check out the [documentation](http://mikefarah.github.io/yq/) for more detailed and advanced usage.
 
 ```
+yq is a lightweight and portable command-line YAML processor. It aims to be the jq or sed of yaml files.
+
 Usage:
   yq [flags]
   yq [command]
@@ -91,9 +93,9 @@ Available Commands:
   help        Help about any command
   merge       yq m [--inplace/-i] [--doc/-d index] [--overwrite/-x] [--append/-a] sample.yaml sample2.yaml
   new         yq n [--script/-s script_file] a.b.c newValue
+  prefix      yq p [--inplace/-i] [--doc/-d index] sample.yaml a.b.c
   read        yq r [--doc/-d index] sample.yaml a.b.c
   write       yq w [--inplace/-i] [--script/-s script_file] [--doc/-d index] sample.yaml a.b.c newValue
-  prefix      yq p [--inplace/-i] [--doc/-d index] sample.yaml a.b.c
 
 Flags:
   -h, --help      help for yq
@@ -110,8 +112,8 @@ Use "yq [command] --help" for more information about a command.
 3. add unit tests
 4. apply changes (use govendor with a preference to [gopkg](https://gopkg.in/) for package dependencies)
 5. `make [local] build`
-6. If required, update the user documentation 
+6. If required, update the user documentation
     - Update README.md and/or documentation under the mkdocs folder
     - `make [local] build-docs`
-    - browse to docs/index.html and check your changes 
+    - browse to docs/index.html and check your changes
 7. profit

commands_test.go

@@ -24,7 +24,18 @@ func TestRootCmd(t *testing.T) {
 	if !strings.Contains(result.Output, "Usage:") {
 		t.Error("Expected usage message to be printed out, but the usage message was not found.")
 	}
+}
 
+func TestRootCmd_Help(t *testing.T) {
+	cmd := getRootCommand()
+	result := runCmd(cmd, "--help")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	if !strings.Contains(result.Output, "yq is a lightweight and portable command-line YAML processor. It aims to be the jq or sed of yaml files.") {
+		t.Error("Expected usage message to be printed out, but the usage message was not found.")
+	}
 }
 
 func TestRootCmd_VerboseLong(t *testing.T) {
@@ -906,9 +917,9 @@ func TestDeleteSplatArrayYaml(t *testing.T) {
 	content := `a: 2
 b:
  hi:
-  - thing: item1 
+  - thing: item1
     name: fred
-  - thing: item2 
+  - thing: item2
     name: sam
 `
 	filename := writeTempYamlFile(content)

docs/sitemap.xml

@@ -2,42 +2,42 @@
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
     <url>
      <loc>None</loc>
-     <lastmod>2019-04-29</lastmod>
+     <lastmod>2019-05-14</lastmod>
      <changefreq>daily</changefreq>
     </url>
 </urlset>

yq.go

@@ -40,7 +40,9 @@ func main() {
 func newCommandCLI() *cobra.Command {
 	yaml.DefaultMapType = reflect.TypeOf(yaml.MapSlice{})
 	var rootCmd = &cobra.Command{
-		Use: "yq",
+		Use:   "yq",
+		Short: "yq is a lightweight and portable command-line YAML processor.",
+		Long:  `yq is a lightweight and portable command-line YAML processor. It aims to be the jq or sed of yaml files.`,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			if version {
 				cmd.Print(GetVersionDisplay())