什么是＆QUOT; =〜＆QUOT;运营商在shell脚本呢？ [英] What does the "=~" operator do in shell scripts?

问题描述

这似乎是那种比较运算，但正是它在如确实以下code（从<一所href=\"https://github.com/lvv/git-prompt/blob/master/git-prompt.sh#L154\">https://github.com/lvv/git-prompt/blob/master/git-prompt.sh#L154)?

It seems that it is sort of comparison operator, but what exactly it does in e.g. the following code (taken from https://github.com/lvv/git-prompt/blob/master/git-prompt.sh#L154)?

    if [[ $LC_CTYPE =~ "UTF" && $TERM != "linux" ]];  then
            elipses_marker="…"
    else
            elipses_marker="..."
    fi

我目前正在试图使混帐提示的MinGW下工作，并与MinGW的提供的外壳似乎并不支持这个操作：

I'm currently trying to make git-prompt to work under MinGW, and the shell supplied with MinGW doesn't seem to support this operator:

conditional binary operator expected
syntax error near `=~'
`        if [[ $LC_CTYPE =~ "UTF" && $TERM != "linux" ]];  then'

在这个特定的情况下，我可以只用 elipses_marker =更换整个块...（因为我知道我的终端支持UNI code），但究竟是什么这个 =〜呢？

In this specific case I can just replace the entire block with elipses_marker="…" (as I know my terminal supports unicode), but what exactly this =~ does?

推荐答案

这是一个唯一的庆典，除了内置的 [命令，执行的正则表达式（模糊）匹配。

It's a bash-only addition to the built-in [[ command, performing regexp (fuzzy) matching.

在此情况下，如果 $ LC_CTYPE 的包含的字符串UTF。

In this case, if $LC_CTYPE CONTAINS the string "UTF".

更多携带版：

if test `echo $LC_CTYPE | grep -c UTF` -ne 0 -a "$TERM" != "linux"
then
  ...
else
  ...
fi

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