This script performs common user management tasks:

#!/bin/bash 
#Filename: user_adm.sh 
#Description: A user administration tool 

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 existing 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 

case $1 in 

  -adduser) [ $# -ne 3 ] && usage ; useradd $2 -p $3 -m ;;  
  -deluser) [ $# -ne 2 ] && usage ; deluser $2 --remove-all-files;; 
  -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 ;; 
  *) usage ;; 
esac 

A sample output resembles the following:

# ./user_adm.sh -details test
Login: test                 Name: 
Directory: /home/test                 Shell: /bin/sh
Last login Tue Dec 21 00:07 (IST) on pts/1 from localhost
No mail.
No Plan.
Last password change          : Dec 20, 2010
Password expires          : never
Password inactive         : never
Account expires             : Oct 10, 2010
Minimum number of days between password change    : 0
Maximum number of days between password change    : 99999
Number of days of warning before password expires  : 7