adadaadaddq

#!/bin/bash


#This function tests if a line is empty or a comment
#returns:(0 if line is not empty/comment)&&(1 if the line is a comment or empty)
function line_is_valid () {
    if [[ $1 == \#* ]] ||  [[ -z $1 ]]
    then
        return 1
    else
        return 0
    fi
}


#This function is used to initialize a url inside source.If the url doesnt exist in source.txt ,it is added
# and the appropriate stdout is printed
#returns:(0 if the url was initialized)&&(1 if the url has already been initialized)
function init () {
    if ! grep -q "$1" source.txt
    then
        if curl -s "$1" > temp.txt
        then
            md5="$(md5sum temp.txt | awk '{ print $1 }')"
            echo $md5 $1 >> source.txt
            echo "$1 INIT"
            return 0;
        else
            echo "$1 FAILED"

        fi
    fi
    return 1;
}





function search_update() {

    if ! grep -q "$1" source.txt
    then
        if curl -s "$1" > temp.txt
        then
            less temp.txt
            md5="$(md5sum temp.txt | awk '{ print $1 }')"
            echo "HASH: $md5 URL:$1 ">> errorlog.txt
            echo $md5 $1 >> source.txt
            echo "$1 INIT"
        else
            echo "$1 FAILED"
        fi

    else

        if curl -s "$1" > temp.txt
        then
            less temp.txt
            newHash="$(md5sum temp.txt | awk '{ print $1 }')"
            prevHash="$(grep "$1" source.txt | awk '{ print $1 }')"
            echo "New=$newHash prev=$prevHash Url = $1" >> errorlog.txt
            if ! [ "$newHash" = "$prevHash" ]
            then
                echo $1
                sed -i "s/$prevHash/$newHash/" source.txt
            fi
        else
            echo "$1 FAILED"
        fi
    fi
}







#Making sure that source.txt exists
if ! [[ -r source.txt ]]
then
    touch source.txt
fi
#fetching all urls
while read row
do
    if  line_is_valid $row
    then
    urls="$urls $row "
    fi
done < $1



for url in $urls
do
    search_update $url &
done
wait