##acl MoinPagesEditorGroup:read,write,delete,revert All:read Join two files on a common field and re-arrange the output: {{{ $ cat a.txt cust1, ac1, 100 cust2, ac2, 200 $ cat b.txt 100000, cust1, 100 2000000, cust2, 200 $ join -a 1 -a 2 -1 3 -2 3 -t"," -o 1.1 1.2 1.3 2.1 a.txt b.txt cust1, ac1, 100,100000 cust2, ac2, 200,2000000 }}} the input files need to be sorted based on the comparison key Using awk in a shell script {{{ File1 = chr locations File2 = GFF file awk ' NR==FNR{ a[NR]=$0 next } { for(i=1;i $4 && a[i] < $5) print $2,$3, "falls between", $4 "and", $5 "at location", a[i] } ' File1 File2 > Outfile_Chr1 & }}}