使用bash可以简化以下操作:

With bash this can be done simplier like:

for f in *;do
echo "$f" "${f%.*}hallo.${f##*.}"
done

示例:

$ ls -all
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file1.txt
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file2.txt
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file3.txt
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file4.txt
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file5.txt 

$ for f in *;do mv -v "$f" "${f%.*}hallo.${f##*.}";done
'file1.txt' -> 'file1hallo.txt'
'file2.txt' -> 'file2hallo.txt'
'file3.txt' -> 'file3hallo.txt'

$ ls -all
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file1hallo.txt
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file2hallo.txt
-rw-r--r-- 1 29847 29847    0 Aug 21 14:33 file3hallo.txt

之所以有效，是因为 $ {f％.*} 返回不带扩展名的文件名-从末尾(向后)删除所有(*)直到找到的第一个/最短点.

This works because ${f%.*} returns filename without extension - deletes everything (*) from the end (backwards) up to first/shortest found dot.

另一方面，这个 $ {f ## *.} 删除从开始到找到的最长点的所有内容，仅返回扩展名.

On the other hand this one ${f##*.} deletes everything from the beginning up to the longest found dot, returning only the extension.

要克服注释中指出的无扩展名文件问题，您可以执行以下操作:

To overcome the extensionless files problem as pointed out in comments you can do something like this:

$ for f in *;do [[ "${f%.*}" != "${f}" ]] && echo "$f" "${f%.*}hallo.${f##*.}" || echo "$f" "${f%.*}hallo"; done
file1.txt file1hallo.txt
file2.txt file2hallo.txt
file3.txt file3hallo.txt
file4 file4hallo
file5 file5hallo

如果文件没有扩展名，则将产生正确的"$ {f％.*}" =="$ {f}"

If the file has not an extension then this will yeld true "${f%.*}" == "${f}"