your code is working when the user inputs the name correctly the first time , but if he gives a wrong name the first time , so i am doing this

while (!-e $filename)
     { 
          print "-*-*--*-*--*-*--*-*--*-*--*-*--*-*--*-*--*-*--*-*--*-
+*--*-*--*-*--*-*--*-*--*-*--*-*--*-*-\n";
          print STDERR "\n$filename not found. \n Ensure that you have
+ given the correct file name\n and the file exists in the working dir
+ectory \n.";
          print "Re-enter filename, or q to quit: ";
          $filename = <STDIN>;
          chomp $filename;
         # my @filenam = split ('\.', $filename);
          exit() if $filename eq "q";
     }
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the line commented out by me is what I did so everytime user inputs the file name it should get updated but its not happening , can you tell me why

Is this what you mean?

#!/usr/bin/perl 
use strict;
use warnings;

my $ending = "txt";

print STDERR "Enter filename: ";
my $fileName = <STDIN>;
chomp $fileName;

while (!-e "$fileName")

    {
        print STDERR "$fileName not found. Try again, or quit (q): ";
        $fileName = <STDIN>;
        chomp $fileName;
        exit () if $fileName eq "q";
    }

my @name = split ('\.', $fileName);
$name[$#name] = $ending if @name >= 2;
push(@name, $ending) if @name == 1;
my $newFileName = join(".", @name);

print STDERR "\nOLD: $fileName\nNEW: $newFileName\n\n";

open (IN, "<", $fileName);
open (OUT, ">", $newFileName);

while (<IN>)
    {
        #do stuff...
        #print OUT "output";
    }
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-Michael