>>228
シェルスクリプトのスレで聞いたほうがいいんじゃないか?

$ cat for-loop.sh
#! /usr/bin/env bash

for file in "$@"; do
echo "-----"
echo "input : $file"
echo "output: ${file%.*}.m4a"
done

$ ls *.aac
bar.aac foo.aac

$ ./for-loop.sh *.aac
-----
input : bar.aac
output: bar.m4a
-----
input : foo.aac
output: foo.m4a