sekib

#!/bin/bash

while :
do
    if [ $(ls *.pdf | wc -l) -eq 1 ]
    then
        file_name=$(ls *.pdf)
        mv $file_name 1.pdf
    else
        the_biggest=$(ls *.pdf | gawk -F\. '{ if(match($1,/^[0-9]*$/,m)) if ( m[0] > max ) max = m[0] } END { print max }')
        for file in $(ls *.pdf)
        do
            numbers='0-9'
            filename=$(cut -d "." -f1 <<< $file)
            if [[ ! $filename =~ [$numbers] ]]
            then
                new_name=$(expr $the_biggest + 1)
                mv $file $new_name.pdf
            fi
        done
    fi
    sleep 60
done