用户管理的shell script

#!/bin/bash
#Shell name: user_adm.sh
#Program:
# A user administration tool
#
#Author:pero
#Email: [email protected]
#History:
# 2012/7/22
#Usage: vi user_adm.sh :set ff=unix
#
#If you have any opinion please contact me

PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:.
export PATH

function usage()
{
 echo Usage:
 echo Add a new user
 echo $0 --adduser username password
 echo
 echo Remove an existing user
 echo $0 --deluser username
 echo
 echo Set the default shell for the user
 echo $0 --shell username SHELL_PATH
 echo
 echo Suspend a user account
 echo $0 --disable username
 echo
 echo Enable a suspended user account
 echo $0 --enable username
 echo
 echo Set expiry date for user account
 echo $0 --expiry DATE
 echo
 echo Change password for user account
 echo $0 --passwd username
 echo
 echo Create a new user group
 echo $0 --newgroup groupname
 echo
 echo Remove an exisitng user group
 echo $0 --delgroup groupname
 echo
 echo Add a user to a group
 echo $0 --addgroup username groupname
 echo
 echo Show details about a user
 echo $0 --details username
 echo
 echo Show usage
 echo $0 --usage
 echo
 exit
}

if [ $UID -ne 0 ];
then
 echo Run $0 as root.
 exit 2
fi

if [ $# -eq 0 ]
then
 echo Show usage
 echo $0 --usage
 echo
fi

case $1 in

 --adduser)  [ $# -ne 3 ] && usage ; useradd $2 -p $3 ;;
 --deluser)  [ $# -ne 2 ] && usage ; deluser $2 ;;
 --shell)    [ $# -ne 3 ] && usage ; chsh $2 -s $3 ;;
 --disable)  [ $# -ne 2 ] && usage ; usermod -L $2 ;;
 --enable)   [ $# -ne 2 ] && usage ; usermod -U $2  ;;
 --expiry)   [ $# -ne 3 ] && usage ; chage $2 -E $3 ;;
 --passwd)   [ $# -ne 2 ] && usage ; passwd $2 ;;
 --newgroup) [ $# -ne 2 ] && usage ; addgroup $2 ;;
 --delgroup) [ $# -ne 2 ] && usage ; delgroup $2 ;;
 --addgroup) [ $# -ne 3 ] && usage ; addgroup $2 $3 ;;
 --details)  [ $# -ne 2 ] && usage ; finger $2 ; chage -l $2 ;;
 --usage) usage ;;
 *) echo "$0 --usage to help";
esac