用Shell写一个递归列出某目录下所有文件的脚本

#! /bin/bash
function read_dir(){
    for file in `ls $1`
    do
        if [ -d $1"/"$file ]
        then
            read_dir $1"/"$file
        else
            echo $1"/"$file
        fi
    done
}

read_dir a