Your sample data seems inconsistent and the code is therefore confusing (update: to me :).

Firstly, it seems as if the name of the sample data file is being passed to load_sketch() as the $sketch_file string. Is this true?

Secondly, most lines of the sample data are in the format
    sgw sketch sgwpts1 format EMS,SGW1,%date%,%time%,%sgw-vpnname%,%sgw-vpnid%,%sgw-servname%,%sgw-servid%
whereas line 4 is
    sgw sketch,sgwptsH,format EMS,SGWH,%date%,%time%,%sgw-vpnname%,%sgw-vpnid%,%sgw-servname%,%sgw-servid%
(commas are in different columns). Executing the statement
    my @all_columns = split(',', $_);
on the sample data will produce substrings with very different formats in $all_columns[1].

Please add an update (see How do I change/delete my post?) to either confirm that the originally posted sample data is in fact correct, or else fix the sample data. (Of course, please cite any updates/changes/additions/corrections; please see How do I change/delete my post?)