Add help command and modify README

README.md

@@ -12,14 +12,13 @@ You can drill down JSON interactively by using filtering queries like [jq](https
 
 ## Installation
 
-* [With homebrew taps (for Mac)](#with-homebrew-taps-for-mac)  
+* [With homebrew (for Mac)](#with-homebrew-for-mac)  
 * [Simply use "jid" command](#simply-use-jid-command)  
 * [Build](#build)  
 
-### With homebrew taps (for Mac)
+### With homebrew (for Mac)
 
 ```
-brew tap simeji/jid
 brew install jid
 ```
 
@@ -75,7 +74,7 @@ This json is used by [demo section](https://github.com/simeji/jid#demo).
 echo '{"info":{"date":"2016-10-23","version":1.0},"users":[{"name":"simeji","uri":"https://github.com/simeji","id":1},{"name":"simeji2","uri":"https://example.com/simeji","id":2},{"name":"simeji3","uri":"https://example.com/simeji3","id":3}],"userCount":3}}'|jid
 ```
 
-#### With initial query
+#### With a initial query
 
 First argument of `jid` is initial query.
 (Use JSON same as [Demo](#demo))
@@ -90,14 +89,20 @@ Sample for using [RDAP](https://datatracker.ietf.org/wg/weirds/documents/) data.
 curl -s http://rdg.afilias.info/rdap/domain/example.info | jid
 ```
 
+#### Load JSON from a file
+
+```
+jid < file.json
+```
+
 ## Keymaps
 
 |key|description|
 |:-----------|:----------|
 |`TAB` / `CTRL` + `I` |Show available items and choice them|
 |`CTRL` + `W` |Delete from the cursor to the start of the word|
-|`CTRL` + `F` / Right Arrow (:arrow_right:)|To the first character of the 'Filter'|
-|`CTRL` + `B` / Left Arrow (:arrow_left:)|To the end of the 'Filter'|
+|`CTRL` + `F` / Right Arrow (:arrow_right:)|Move cursor a character to the right|
+|`CTRL` + `B` / Left Arrow (:arrow_left:)|Move cursor a character to the left|
 |`CTRL` + `A`|To the first character of the 'Filter'|
 |`CTRL` + `E`|To the end of the 'Filter'|
 |`CTRL` + `J`|Scroll json buffer 1 line downwards|

cmd/jid/jid.go

@@ -14,13 +14,21 @@ func main() {
 	content := os.Stdin
 
 	var qm bool
+	var help bool
 	var version bool
 	qs := "."
 
 	flag.BoolVar(&qm, "q", false, "Output query mode")
+	flag.BoolVar(&help, "h", false, "print a help")
+	flag.BoolVar(&help, "help", false, "print a help")
 	flag.BoolVar(&version, "version", false, "print the version and exit")
 	flag.Parse()
 
+	if help {
+		fmt.Println(getHelpString())
+		os.Exit(0)
+	}
+
 	if version {
 		fmt.Println(fmt.Sprintf("jid version v%s", VERSION))
 		os.Exit(0)
@@ -52,3 +60,42 @@ func run(e jid.EngineInterface, qm bool) int {
 	}
 	return 0
 }
+
+func getHelpString() string {
+	return `
+
+============ Load JSON from a file ==============
+
+$ jid < file.json
+
+============ With a JSON filter mode =============
+
+TAB / CTRL-I
+  Show available items and choice them
+
+CTRL-W 
+  Delete from the cursor to the start of the word
+
+CTRL-F / Right Arrow
+  Move cursor a character to the right
+
+CTRL-B / Left Arrow
+  Move cursor a character to the left
+
+CTRL-A
+  To the first character of the 'Filter'
+
+CTRL-E
+  To the end of the 'Filter'
+
+CTRL-J
+  Scroll json buffer 1 line downwards
+
+CTRL-K
+  Scroll json buffer 1 line upwards
+
+CTRL-L
+  Change view mode whole json or keys (only object)
+
+`
+}