使用以下的热键可以有效地在命令行下敲命令：
To effectively construct commands on the command line make use of the following hotkeys:
ctrl-w 删除最后一个单词to delete the last word;
ctrl-u 删除光标之前的所有内容to delete all the way back to the start of the line;
ctrl-k 删除光标之后的所有内容to delete up to the end of the line;
alt-f 光标向后移动到下一个单词to move forward by one word;
alt-b 光标向前移动到上一个单词to move backwards by one word
ctrl-a 光标移动到行首to move to the beginning of the line;
ctrl-e 光标移动到行尾to move to the end of the line;
