Shell Programming and Scripting

bart simpson , andHisPassword
maggy simpson , andHisPassword

#!/bin/bash # Script to add a user to Linux system 
if [ $(id -u) -eq 0 ]; then 	
read -p "Enter username : " username 	
read -s -p "Enter password : " password 	
egrep "^$username" /etc/passwd >/dev/null 	
if [ $? -eq 0 ]; then 		
   echo "$username exists!" 		
   exit 1 	
else 		
  pass=$(perl -e 'print crypt($ARGV[0], "password")' $password) 		
  useradd -m -p $pass $username 		
  if  [ $? -eq 0 ]; then  
     echo "User has been added to system!" 
  else
     echo "Failed to add a user!" 	
  fi 
  else 	
      echo "Only root may add a user to the system" 	
      exit 2 
fi

root@nio:/tmp# cat file
bart_simpson,andHisPassword
maggy_simpson,andHisPassword

root@nio:/tmp# cat adduser.sh
#!/bin/bash

if [ $# -lt 1 ]
  then
    echo "Usage : $0 userfile"
    exit
fi

if [ $(id -u) -eq 0 ]; then 	
	

while IFS=, read username password; do

	if egrep "^$username" /etc/passwd >/dev/null;  then 		
   		echo "$username exists!" 			
	else 		
  		password=$(perl -e 'print crypt($ARGV[0], "password")' $password) 		
  		
		if  useradd -m -p "$password" "$username" >/dev/null; then  
     			echo "User '$username' has been added to system!" 
  		else
     			echo "Failed to add  user '$username'!" 	
  		fi 
	fi
done <"$@"

else 	
      echo "Only root may add a user to the system" 	
      exit 
fi

root@nio:/tmp# sh adduser.sh file
User 'bart_simpson' has been added to system!
User 'maggy_simpson' has been added to system!

root@nio:/tmp# tail -2 /etc/passwd
bart_simpson:x:1001:1002::/home/bart_simpson:/bin/sh
maggy_simpson:x:1002:1003::/home/maggy_simpson:/bin/sh

akshay@nio:/tmp$ su bart_simpson
Password: andHisPassword
$ whoami
bart_simpson

while IFS=, read username password; do
..
..
done <"$@"