shell 提示符

 

rivsidn@rivsidn:~$ echo ${PS1}
\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$

 

 

The default $PS1 in Ubuntu consists of three parts:

  • \[\e]0;\u@\h: \w\a\]

    This is an escape sequence which will set the terminal title text to $USER@$HOST: $PWD.

    \[ and \] indicate the beginning and end of a sequence of non-printing characters.

    \e is an ASCII escape character.

    ]0; is the specific escape sequence to set the terminal icon and title in xterm compatible terminals

    \u expands to the username of the current user.

    @ is a literal @.

    \h expands to the hostname.

    : is a literal colon character.

    \w expands to the current working directory.

    \a is an ASCII bell character.

  • ${debian_chroot:+($debian_chroot)}

    If you're in a chroot environment, this will expand to the name of the chroot in parentheses.

    ${var:+OTHER} evaluates to $OTHER if var is set, otherwise as null string. $debian_chrootis a variable initalized in /etc/bash.bashrc to the contents of the file /etc/debian_chroot. Thus if your chroot environment includes this file, the prompt will include the contents of that file as an indication for which chroot the shell currently operates in.

  • \u@\h:\w\$

    This is the actual prompt you typically see.

    \u, @, \h, :, \w are as above.

    \$ expands to a number sign # if the effective uid is zero (i.e. user is root), otherwise it expands to a dollar sign $.

Resources

 

 

参考资料：

 

posted on 2019-07-15 22:30  rivsidn  阅读(147)  评论(0)  编辑  收藏  举报

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