shell_checkdir

#!/bin/bash
FILE_THIS="/home/Test/this.txt"
FILE_LAST="/home/Test/last.txt"
FOLDER="/home/Test/" #被检测的文件夹
while :;do #死循环
	if [ -e "$FILE_THIS" ]; then 
		mv "$FILE_THIS" "$FILE_LAST"
		ls "$FOLDER" > "$FILE_THIS" 
		diff "$FILE_THIS" "$FILE_LAST"
		if [ $? == 0 ]; then
			echo Not change
		else
			php change.php
	fi
	else
		ls "$FOLDER" > "$FILE_THIS"
	fi
	sleep 1
done

if [ -e filename ] #只要 filename 存在，则为真

diff "$FILE_THIS" "$FILE_LAST" #比较两个文件的差异