LinuxQuestions.org - /etc/passwd & /etc/shadow

I found this shell script:

Code:

#!/bin/bash

# Script to add a user to Linux system

# -------------------------------------------------------------------------

# Copyright (c) 2007 nixCraft project <http://bash.cyberciti.biz/>

# This script is licensed under GNU GPL version 2.0 or above

# Comment/suggestion: <vivek at nixCraft DOT com>

# -------------------------------------------------------------------------

# See url for more info:

# http://www.cyberciti.biz/tips/howto-write-shell-script-to-add-user.html

# -------------------------------------------------------------------------

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

                [ $? -eq 0 ] && echo "User has been added to system!" || echo "Failed to add a user!"

        fi

else

        echo "Only root may add a user to the system"

        exit 2

fi

can I execute this script with a shell_exec() php fuction, and I want to pass $pass and $username from a HTML textfields. if I can, HOW?