shell初级编程

功能：判断输入的用户名是否存在与/etc/passwd中

#!/bin/bash

if [ $# -le 0 ];then
	echo "Please input the right arg"
else
	i=`cat /etc/passwd | cut -f1 -d':' | grep -w "$1" -c `
	if [ $i -le 0 ];then
		echo "User $1 is not in the passwd"
	else
		echo "User $1 is in the passwd"
		fi
fi