Readline

Readline 是來自 GNU Project 的庫，Bash 和其他命令行界面的程序使用它在命令行編輯和交互。詳情請參閱 readline(3)。

安裝

readline^包 包很可能已作為 Bash 的依賴安裝。

編輯模式

Readline 默認使用 Emacs 風格的快捷鍵與命令行交互。不過，vi 風格的編輯界面也受支持，但需要將以下內容添加到 ~/.inputrc：

~/.inputrc

set editing-mode vi

或者，要只為 Bash 設置，你可將以下內容添加到 ~/.bashrc：

~/.bashrc

set -o vi

提示中的模式指示符

Vi 風格的編輯有兩種模式：命令模式和插入模式。你可通過添加以下命令顯示當前的模式：

~/.inputrc

set show-mode-in-prompt on

這將在你的提示中顯示模式（默認是 (cmd)/(ins)），顯示的內容可通過 vi-ins-mode-string 和 vi-cmd-mode-string 變量自定義。

為每個模式指定不同的光標樣式

你可以使用"\1 .. \2" 轉義符為每個模式指定不同的光標樣式：

~/.inputrc

set vi-ins-mode-string \1\e[6 q\2
set vi-cmd-mode-string \1\e[2 q\2

這將在命令模式中顯示方塊形狀的光標，在插入模式中顯示豎線形狀的光標。注意，你必須先啟用模式指示符（見#提示中的模式指示符）。

Virtual Console 使用不同的轉義代碼，因此你應先檢查使用的是哪種終端：

~/.inputrc

$if term=linux
	set vi-ins-mode-string \1\e[?0c\2
	set vi-cmd-mode-string \1\e[?8c\2
$else
	set vi-ins-mode-string \1\e[6 q\2
	set vi-cmd-mode-string \1\e[2 q\2
$endif

詳情請參閱 software cursor for VGA。

Fast word movement

Xterm 默認支持使用 Ctrl+Left 和 Ctrl+Right 在單詞間移動。要在其他終端模擬器中實現這一效果，先找到正確的終端代碼，然後在 ~/.inputrc 中綁定到 backward-word 和 forward-word。

例如，對於 urxvt：

~/.inputrc

"\e[1;5D": backward-word
"\e[1;5C": forward-word

歷史

通常，無論你輸入了什麼，按向上箭頭都會出現上一次輸入的命令。然而，用戶可能會覺得只顯示匹配剛剛輸入的內容的命令更實用。

例如，假設輸入了以下命令：

• ls /usr/src/linux-2.6.15-ARCH/kernel/power/Kconfig
• who
• mount
• man mount

此時，當輸入 ls 並按向上箭頭，輸入將會被替換為 man mount。如果你使用了歷史搜索功能，那麼只有過去以 ls（當前的輸入）開頭的命令會被顯示，在這裡就是 ls /usr/src/linux-2.6.15-ARCH/kernel/power/Kconfig。

要啟用歷史搜索功能，只需把以下內容加入到 /etc/inputrc 或者 ~/.inputrc：

"\e[A": history-search-backward
"\e[B": history-search-forward

如果你使用 vi 模式，添加以下內容到 ~/.inputrc（來自這個帖子）：

set editing-mode vi
$if mode=vi
set keymap vi-command
# these are for vi-command mode
"\e[A": history-search-backward
"\e[B": history-search-forward
j: history-search-forward
k: history-search-backward
set keymap vi-insert
# these are for vi-insert mode
"\e[A": history-search-backward
"\e[B": history-search-forward
$endif

如果你選擇將這些內容添加到 ~/.inputrc，那建議你同時在文件的開始添加以下內容，以避免像這樣的怪事：

$include /etc/inputrc

Alternatively, one can use reverse-search-history (incremental search) by pressing Ctrl+R, which does not search based on previous input but instead jumps backwards in the history buffer as commands are typed in a search term. Pressing Ctrl+R again during this mode will display the previous line in the buffer that matches the current search term, while pressing Ctrl+G (abort) will cancel the search and restore the current input line. So in order to search through all previous mount commands, press Ctrl+R, type 'mount' and keep pressing Ctrl+R until the desired line is found.

The forward equivalent to this mode is called forward-search-history and is bound to Ctrl+S by default. Beware that most terminals override Ctrl+S to suspend execution until Ctrl+Q is entered. (This is called XON/XOFF flow control). For activating forward-search-history, either disable flow control by issuing:

$ stty -ixon

或者在 inputrc 中使用不同的鍵。例如，要使用默認未綁定的 Alt+S：

"\es": forward-search-history

Faster completion

When performing tab completion, a single tab attempts to partially complete the current word. If no partial completions are possible, a double tab shows all possible completions.

The double tab can be changed to a single tab by setting:

~/.inputrc

set show-all-if-unmodified on

Or you can set it such that a single tab will perform both steps: partially complete the word and show all possible completions if it is still ambiguous:

~/.inputrc

set show-all-if-ambiguous on

Colorized completion

You can enable coloring of completion of filenames with the colored-stats option. You can also color the identical prefix of completion-lists with colored-completion-prefix. For example:

~/.inputrc

# Color files by types
# Note that this may cause completion text blink in some terminals (e.g. xterm).
set colored-stats On
# Append char to indicate type
set visible-stats On
# Mark symlinked directories
set mark-symlinked-directories On
# Color the common prefix
set colored-completion-prefix On
# Color the common prefix in menu-complete
set menu-complete-display-prefix On

宏

Readline also supports binding keys to keyboard macros. For simple example, run this command in Bash:

bind '"\ew": "\C-e # macro"'

or add the part within single quotes to inputrc:

"\ew": "\C-e # macro"

Now type a line and press Alt+W. Readline will act as though Ctrl+E (end-of-line) had been pressed, appended with ' # macro'.

Use any of the existing keybindings within a readline macro, which can be quite useful to automate frequently used idioms. For example, this one makes Ctrl+Alt+L append "| less" to the line and run it (Ctrl+M is equivalent to Enter):

"\e\C-l": "\C-e | less\C-m"

The next one prefixes the line with 'yes |' when pressing Ctrl+Alt+Y, confirming any yes/no question the command might ask:

"\e\C-y": "\C-ayes | \C-m"

This example wraps the line in su -c '', if Alt+S is pressed:

"\es": "\C-a su -c '\C-e'\C-m"

This example prefixes the line with sudo , if Alt+S is pressed. It is safer because it will not input the Enter key.

"\es": "\C-asudo \C-e"

As a last example, quickly send a command in the background with Ctrl+Alt+B, discarding all of its output:

"\e\C-b": "\C-e > /dev/null 2>&1 &\C-m"

禁用 control 回顯

Readline 使得終端在按下 Ctrl+C 後回顯 ^C。要禁用，只需將以下內容添加到 ~/.inputrc：

set echo-control-characters off

參閱

• vi readline 編輯速查表
• emacs readline 編輯速查表