如何从shell使用fnmatch? [英] How to use fnmatch from a shell?

问题描述

在通用的shell脚本中，我想使用shell模式匹配来过滤文本文件的行.

In a generic shell script, I would like to use shell pattern matching to filter the lines of a text file.

我在files.txt中有一个文件名列表:

I have a list of file names in files.txt:

file1.txt
file2.sh
file3.png

我在patterns.txt中有一个模式列表:

And I have a list of patterns in patterns.txt:

other_file.txt
file2.*

如果我在patterns.txt中有正则表达式，我可以这样做:

If I would have regular expressions in patterns.txt, I could do this:

$ grep -v -f patterns.txt files.txt

但是我想使用Shell Globing模式.我找到了C函数fnmatch，但没有使用它的shell/unix命令.

But I would like to use shell globbing patterns. I found the C function fnmatch but no shell/unix command to use it.

推荐答案

好的，这真的很糟糕，因为POSIX sh甚至没有数组(我本该用于缓存模式):

OK, this is going to be really unperformant, as POSIX sh does not even have arrays (which I would have used for caching the patterns):

while IFS= read -r filename; do
    hasmatch=0
    while IFS= read -r pattern; do
        case $filename in ($pattern) hasmatch=1; break ;; esac
    done <patterns.txt
    test $hasmatch = 1 || printf '%s\n' "$filename"
done <files.txt

如果不需要位置参数($1，$2，...)，则可以通过以下方式将其用于模式缓存:

If you don’t need the positional arguments ($1, $2, …) you can abuse those for pattern caching though:

saveIFS=$IFS; IFS='
'; set -o noglob
set -- $(cat patterns.txt)
IFS=$saveIFS; set +o noglob
while IFS= read -r filename; do
    hasmatch=0
    for pattern in "$@"; do
        case $filename in ($pattern) hasmatch=1; break ;; esac
    done
    test $hasmatch = 1 || printf '%s\n' "$filename"
done <files.txt

但是请注意其中的空白:我们将IFS设置为文字换行符，而没有其他设置，即IFS=' Enter '.

Be careful about whitespace there though: we set IFS to a literal newline character and nothing else, i.e. IFS='Enter'.

我已经使用您的数据集对它进行了测试，并添加了一些附加内容(例如a b*模式，以测试空白行为)，并且根据OP中的规范，它似乎对我有用.

I’ve tested this with your dataset plus a few additions (like a a b* pattern, to test whitespace behaviour), and it seems to work for me according to the spec in the OP.

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