在 bash 中检查文件扩展名的最简单方法？
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Easiest way to check for file extension in bash?
提问by Liam
I have a shell script where I need to do one command if a file is zipped (ends in .gz) and another if it is not. I'm not really sure how to approach this, here's an outline of what I'm looking for:
我有一个 shell 脚本，如果文件被压缩（以 .gz 结尾），我需要在其中执行一个命令，如果不是，则需要执行另一个命令。我不太确定如何解决这个问题，以下是我正在寻找的内容的概述：
file=/path/name*
if [ CHECK FOR .gz ]
then echo "this file is zipped"
else echo "this file is not zipped"
fi
回答by rici
You can do this with a simple regex, using the =~operator inside a [[...]]test:
你可以用一个简单的正则表达式来做到这一点，=~在[[...]]测试中使用运算符：
if [[ $file =~ \.gz$ ]];
This won't give you the right answer if the extension is .tgz, if you care about that. But it's easy to fix:
如果扩展名是.tgz，这不会给你正确的答案，如果你关心的话。但它很容易修复：
if [[ $file =~ \.t?gz$ ]];
The absence of quotes around the regex is necessary and important. You could quote $filebut there is no point.
正则表达式周围没有引号是必要且重要的。你可以引用，$file但没有意义。
It would probably be better to use the fileutility:
使用该file实用程序可能会更好：
$ file --mime-type something.gz
something.gz: application/x-gzip
Something like:
就像是：
if file --mime-type "$file" | grep -q gzip$; then
echo "$file is gzipped"
else
echo "$file is not gzipped"
fi
回答by jthill
Really, the clearest and often easiest way to match patterns like this in a shell script is with case
实际上，在 shell 脚本中匹配这样的模式的最清晰且通常最简单的方法是使用 case
case "$f" in
*.gz | *.tgz )
# it's gzipped
;;
*)
# it's not
;;
esac
回答by Rahul Tripathi
You can try something like this:-
你可以尝试这样的事情：-
if [[ ${file: -3} == ".gz" ]]
