shell 遞歸調用自己

#!/bin/sh
if test "$2" = ""; then
	echo "Usage: $0 basedir depth"
	exit 1
fi

if test "$2" = "0"; then
	exit 0
fi

for i in a b c d e f ; do
	path="$1/$i"
	mkdir $path || exit 1
	sh $0 $path `expr $2 - 1`   #這裏:)
done