linux键盘操作技巧
光标移动：
Ctrl-a Move cursor to the beginning of the line.
Ctrl-e Move cursor to the end of the line.
Ctrl-f Move cursor forward one character; same as the right arrow key.
Ctrl-b Move cursor backward one character; same as the left arrow key.
Alt-f Move cursor forward one word.
Alt-b Move cursor backward one word.
Ctrl-l Clear the screen and move the cursor to the top left corner. The
clear command does the same thing.
修改命令行文本：
Ctrl-d Delete the character at the cursor location
Ctrl-t Transpose (exchange) the character at the cursor location with the
one preceding it.
Alt-t Transpose the word at the cursor location with the one preceding it.
Alt-l Convert the characters from the cursor location to the end of the
word to lowercase.
Alt-u Convert the characters from the cursor location to the end of the
word to uppercase.
命令行中剪切与复制：
Ctrl-k Kill text from the cursor location to the end of line.
Ctrl-u Kill text from the cursor location to the beginning of the line.
Alt-d Kill text from the cursor location to the end of the current word.
Alt-Backspace
Kill text from the cursor location to the beginning of the current
word. If the cursor is at the beginning of a word, kill the previous
word.
Ctrl-y Yank（复制） text from the kill-ring and insert it at the cursor location.
命令行history：
!! 重复上一条命令，相当于副键盘的向上键；
!number 执行history中第number条的命令行；
!string 执行history中以string开始的命令行；
!?string 执行上一条history中包含string的命令行；