为什么模式*([[^ \/])在我的交互式外壳程序中有效但在脚本中无效? [英] Why does the pattern *([^\/]) work in my interactive shell but not a script?

问题描述

我正在编写一个脚本，使用bash参数替换将工作目录剥离到有限的长度.它可以在命令行上运行，但是相同的替换在脚本中什么也没做.

I'm writing a script to strip a working directory to a limited length using bash parameter substitution. It works on the command line, but the same substitution does nothing in the script.

代码:

#!/bin/bash

# Limit of working directory length
LIMIT=10

dir=${1/#$HOME/\~}

# If it's too long, normalize it by stripping ~ and adding ...
if [ ${#dir} -gt $LIMIT ]; then
  dir=${dir/#\~/"..."}
fi

echo $dir

# Strip levels until short enough or can't strip anymore.
while [[ ( ${#dir} -gt $LIMIT ) && ( "$dir" != "$last_dir" ) ]]; do
  last_dir="$dir"
  # Strip a level off.
  dir=${dir/#...\/*([^\/])/"..."} <- broken line
  echo $dir
done

echo $dir

如果我愿意

test=".../School/CS352/Project1"
text=${test/#...\/*([^\/])/"..."}

我得到了.../CS352/Project1，这就是我想要的.但是同一个sub在我的脚本中什么也没做.

I get .../CS352/Project1, which is what I want. But the same sub does nothing in my script.

问题:如何使代码中的标记行表现得像上面的示例一样?

推荐答案

运行:

shopt -s extglob

...打开此支持.

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