pryのhelpでpryの概要を知る

#前置き
Ruby の REPL ではもう irb じゃなく pry を使うのがフツーになってると思います。
ただ、非常に多機能なため、ほとんどの機能を使わずに利用していることが多いと思います。

pry の機能をくわしく紹介してくださってるのが

- [Ruby の 定番対話ツール pry 徹底攻略 #pry #ruby - Qiita](http://qiita.com/tbpgr/items/12a60f2f9e3de61517b5)

なのですが、やはり多機能すぎて、あまり良く見渡せない。
もっと簡単な地図は無いのか。

#本編
すごく単純な事なのですが、やはり `help` にはそのコマンドの簡単な内容が載ってますよね。
私自身が今まで見たことが無かったのに、今回見てみたら簡潔に纏まっていたので、ご紹介したいと思ったわけです（といってもやはり多いですねw）。
以下のメッセージは

```rb
[1]pry(main)> help
```
で返ってくるものを若干編集したものです。

###1. Help
```rb
help               Show a list of commands or information about a specific command.
```
###2. Context
```rb
cd                 Move into a new context (object or scope).
find-method        Recursively search for a method within a class/module or the current namespace.
ls                 Show the list of vars and methods in the current scope.
pry-backtrace      Show the backtrace for the pry session.
raise-up           Raise an exception out of the current pry instance.
reset              Reset the repl to a clean state.
watch              Watch the value of an expression and print a notification whenever it changes.
whereami           Show code surrounding the current context.      (Alias: @)
wtf?               Show the backtrace of the most recent exception.
```
###3. Editing
```rb
/^\s*!\s*$/        Clear the input buffer.
amend-line         Amend a line of input in multi-line mode.
edit               Invoke the default editor on a file.
hist               Show and replay readline history.        (Alias: history)
play               Playback a string variable, method, line, or file as input.
show-input         Show the contents of the input buffer for the current multi-line expression.
```
###4. Introspection
```rb
ri                 View ri documentation.
show-doc           Show the documentation for a method or class. (Alias: ?)
show-source        Show the source for a method or class.        (Alias: $, show-method)
stat               View method information and set _file_ and _dir_ locals.
```
###5. Gems
```rb
gem-cd             Change working directory to specified gem's directory.
gem-install        Install a gem and refresh the gem cache.
gem-list           List and search installed gems.
gem-open           Opens the working directory of the gem in your editor.
```
###6. Commands
```rb
import-set         Import a pry command set.
install-command    Install a disabled command.
```
###7. Input and output
```rb
.<shell command>   All text following a '.' is forwarded to the shell.
cat                Show code from a file, pry's input buffer, or the last exception.
change-inspector   Change the current inspector proc.
change-prompt      Change the current prompt.
fix-indent         Correct the indentation for contents of the input buffer
list-inspectors    List the inspector procs available for use.
list-prompts       List the prompts available for use.
save-file          Export to a file using content from the repl.
shell-mode         Toggle shell mode. bring in pwd prompt and file completion. (Alias: file-mode)
```
###8. Misc
```rb
gist               Upload code, docs, history to https://gist.github.com/.
clipit             Alias for `gist --clip`
pry-version        Show pry version.
reload-code        Reload the source file that contains the specified code object. (Alias: reload-method)
toggle-color       Toggle syntax highlighting.
```
###9. Navigating pry
```rb
!pry               Start a pry session on current self.
disable-pry        Stops all future calls to pry and exits the current session.
exit               Pop the previous binding.    (Alias: quit)
exit-all           End the current pry session. (Alias: !!@)
exit-program       End the current program.     (Alias: !!!, quit-program)
jump-to            Jump to a binding further up the stack.
nesting            Show nesting information.
switch-to          Start a new subsession on a binding in the current stack.
```
###10. Prompts
```rb
simple-prompt      Toggle the simple prompt.
```

`gist` コマンドなんて初めて見ました。