#!/bin/bash
LOCATION=$1
KEYWORD=$2
OPTION=$3
COMPARE=$4
CONDITION=$5

#Example:
#LOCATION="/etc/pam.d/common-password"  
        #For debian is common-password ,for Gentoo and Red hat the file is system-auth
#KEYWORD="pam_cracklib.so"
#OPTION="ocredit"
#COMPARE="gt"
#CONDITION="-1"

if [ -f "$LOCATION" ];then

        RESULT=$(sed -e '/^#/d' -e '/^[ \t][ \t]*#/d' -e 's/#.*$//' -e '/^$/d' $LOCATION | grep "$KEYWORD.*$OPTION")
	#above line is remove any comment in the configuration file and use grep to output a exit status
	#if matched both $KEYWORD and $OPTION there is a success exit status: 0

        if [ $? -eq 0 ];then
	        if [ "$(echo $RESULT | tr "\t" "\n" | tr " " "\n" | sed -n "/$OPTION/p"| awk -F "=" '{printf $2}')" -$(echo $COMPARE) "$CONDITION" ];then
                        exit 1
	        fi
        else
                exit 1
	fi

fi