Question

我想在变量中存储bash字符串比较的结果，效果等同于：

if [[ $a == $b ]]; then
    res=1
else
    res=0
fi

我希望能够写一些更简洁的东西，比如：

res2=$('$a'=='$b') #Not valid bash

有没有办法实现我想要的，而不是推迟if构造？

Answer 1

我建议：

res=0; [ "$a" == "$b" ] && res=1

或

res=1; [ "$a" == "$b" ] || res=0

并不像您希望的那样简单，但确实避免使用if ... else ... fi。

Answer 2

您还可以使用包含上一个命令的返回值的$?变量：

res="$( [[ $a == $b ]]; echo $? )"

虽然这会反转你给出的数字。最终结果将与：

相同

if [[ $a == $b ]]; then
  res=0
else
  res=1
fi

这是因为shell将0的返回值解释为true，将1解释为false。

不是说我完全提倡这个解决方案。这是hackish，有点不清楚。但是你要求的是简洁和简洁。

Answer 3

这是另一种选择。

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在变量中存储bash字符串比较

3 个答案: