I actually did consider the use of anchors. I thought that narrowing the focus to the field of interest would be "good enough". We don't know where this csv data comes from. I suppose that this could potentially come from some spreadsheet or other program which might add "" marks even where not required (but allowed). In that case, something like /^SMS/ would fail.

I think it is highly likely that this data comes from another program rather than from user input. In cases like that, I often write regex'es that allow more matches than a very rigid interpretation because the computer won't "fumble finger" in an extraneous character. All of these types of decisions come down to the exact application which we just don't know.

Overall I think this is a good thread. Although I do wish that the OP had provided more code to put his problem into a wider context. The Monks demonstrated some new points for the OP to consider along with adequate explanations. I hope that the OP reads all this stuff and decides what is right for his application.

Thank you very much for all the replies.To be more clear, now i am working on the below line of code to get the output.I am trying to write some if condition here so that SGWa-i is renamed to SGWa-i_LOWCASE and SGWA-I is renamed to SGWA-I_UPCASE.Sample data is provided below,Earlier i provided the data file with values but here i am providing the basic sketch file which is supposed to be referred

Sample data

sgw sketch sgwpts1 format EMS,SGW1,%date%,%time%,%sgw-vpnname%,%sgw-vp
+nid%,%sgw-servname%,%sgw-servid%
sgw sketch sgwptsh format EMS,SGWh,%date%,%time%,%sgw-vpnname%,%sgw-vp
+nid%,%sgw-servname%,%sgw-servid%
sgw sketch sgwptsi format EMS,SGWi,%date%,%time%,%sgw-vpnname%,%sgw-vp
+nid%,%sgw-servname%,%sgw-servid%
sgw sketch, sgwptsH format, EMS,SGWH,%date%,%time%,%sgw-vpnname%,%sgw-
+vpnid%,%sgw-servname%,%sgw-servid%
sgw sketch sgwptsI format EMS,SGWI,%date%,%time%,%sgw-vpnname%,%sgw-vp
+nid%,%sgw-servname%,%sgw-servid%
[download]

Lines of code i am writing

    sub load_sketch {
    my ($sketch_file) = @_;
    my %all_sketches = ();
    open(DAT, $sketch_file) || die("Could not open file $sketch_file!"
+);
    my @lines = <DAT>;
    close(DAT);
    foreach (@lines) {   
        s/[\r\n\s%]+//g;
        my @all_columns = split(',', $_);
        
        $all_sketches{ uc($all_columns[1]).'STAT' } = [ @all_columns ]
+; # Output file will have SGWSTAT in its name
    }
    return %all_sketches;
}
1;    # tells perl that the package is ready to run
[download]

Please help me in the above code on how to rename or please suggest if there are better ways to handle it here

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?)

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