我应该如何让 bash 3.2 找到通配符之间的模式

发布于 2025-01-08 04:01:07 字数 266 浏览 2 评论 0原文

尝试将输入与包含警报词的文件进行比较，

read MYINPUT
alertWords=( `cat "AlertWordList" `)
for X in "${alertWords[@]}"
do
# the wildcards in my expression do not work
if [[ $MYINPUT =~ *$X* ]] 
then
    echo  "#1 matched"
else
    echo  "#1 nope"
fi
done

原文

Trying to compare input to a file containing alert words,

read MYINPUT
alertWords=( `cat "AlertWordList" `)
for X in "${alertWords[@]}"
do
# the wildcards in my expression do not work
if [[ $MYINPUT =~ *$X* ]] 
then
    echo  "#1 matched"
else
    echo  "#1 nope"
fi
done

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糖果控 2025-01-15 04:01:07

=~ 运算符处理正则表达式，因此要像您想要的那样进行通配符匹配，语法如下所示：

if [[ $MYINPUT =~ .*$X.* ]]

但是，由于这是正则表达式，因此不需要这样做，因为它暗示它可以位于字符串中的任何位置（除非它使用 ^ 和/或 $ 锚定，所以这应该足够了：

if [[ $MYINPUT =~ $X ]]

请注意，如果您的“单词”碰巧包含正则表达式元字符，那么这可能会做奇怪的事情。

The =~ operator deals with regular expressions, and so to do a wildcard match like you wanted, the syntax would look like:

if [[ $MYINPUT =~ .*$X.* ]]

However, since this is regex, that's not needed, as it's implied that it could be anywhere in the string (unless it's anchored using ^ and/or $, so this should suffice:

if [[ $MYINPUT =~ $X ]]

Be mindful that if your "words" happen to contain regex metacharacters, then this might do strange things.

回复收藏 0 原文

彡翼 2025-01-15 04:01:07

我会在这里避免 =~ 因为正如 FatalError 指出的那样，它将把 $X 解释为正则表达式，这可能会导致令人惊讶的错误（特别是因为它是一个扩展的正则表达式）表达式，因此它比标准 grep 语法有更多的特殊字符）。

相反，您可以只使用 == 因为 bash 将 == 的 RHS 视为通配模式：

read MYINPUT
alertWords=($(<"AlertWordList"))
for X in "${alertWords[@]}"
do
# the wildcards in my expression do work :-)
if [[ $MYINPUT == *"$X"* ]] 
then
    echo  "#1 matched"
else
    echo  "#1 nope"
fi
done

我还在您的 alertWords 中删除了 cat 的使用 赋值，因为它使文件在 shell 内读取，而不是生成另一个进程来执行此操作。

I'd avoid =~ here because as FatalError points out, it will interpret $X as a regular expression and this can lead to surprising bugs (especially since it's an extended regular expression, so it has more special characters than standard grep syntax).

Instead, you can just use == because bash treats the RHS of == as a globbing pattern:

read MYINPUT
alertWords=($(<"AlertWordList"))
for X in "${alertWords[@]}"
do
# the wildcards in my expression do work :-)
if [[ $MYINPUT == *"$X"* ]] 
then
    echo  "#1 matched"
else
    echo  "#1 nope"
fi
done

I've also removed a use of cat in your alertWords assignment, as it keeps the file reading inside the shell instead of spawning another process to do it.

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帅哥哥的热头脑 2025-01-15 04:01:07

如果您想使用模式而不是正则表达式进行匹配，可以使用 case：

read MYINPUT
alertWords=( `cat "AlertWordList" `)
for X in "${alertWords[@]}"
do
  # the wildcards in my expression do not work
  case "$MYINPUT" in
    *$X* ) echo "#1 matched" ;;
    * ) echo  "#1 nope" ;;
  esac
done

If you want to use patterns, not regexes for matching, you can use case:

read MYINPUT
alertWords=( `cat "AlertWordList" `)
for X in "${alertWords[@]}"
do
  # the wildcards in my expression do not work
  case "$MYINPUT" in
    *$X* ) echo "#1 matched" ;;
    * ) echo  "#1 nope" ;;
  esac
done

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