Shell function to check if website has changed

function webch(){

    f1=/tmp/.`mcookie`          #File to save webpage in the first time
    f2=/tmp/.`mcookie`          #File to save webpage in to compare to first download
    url=$1                  #Passing the first argument to the variable url
    wget -q -O $f1 $url         #Fetching the page for the first time
    tmp=0                   #Setting tmp to 1
    if [ -z $2 ];               #Checking if time to wait has been supplied (in seconds)
    then
        time=30             #Default if not supplied
        else
        time=$2             #Setting time to what was passed
    fi

    while [ $tmp -eq 0 ] ; do
        sleep $time         #Waiting before fetching the page
        wget -q -O $f2 $url     #Fetching page
        cmp $f1 $f2         #Checking first fetch vs last. cmp exits with 0 if files are the same, 1 if they are different
        tmp=$?              #Setting what cmp exited with to tmp
    done
    rm $f1 $f2              #removing files that are nolonger needed

    if [ $tmp -gt 1 ]           #Checks if cmp gave an error
    then
        echo "An error occured"
        exit 127
    fi

    if [ -z $3 ];               #Checks if an action has been supplied
    then
        echo "It changed!"      #Default output if no action has been supplied
        echo -en "\007"         #Beeps once to notify that a change has occured
    else
        ${@:3}              #Completes supplied command(s)
    fi
    return 0
}