__DATA__ <script type="java/js"> foobie bletch </script> <%-- <script> zelgo mer </script> --> input is same as temporal used.but when i'm executing this code it's not able to make changes in file.i'm using .txt file

temporal used the __DATA__ segment to avoid the need for an external file. You will need to learn how to open a file for reading and then read it in like temporal's code does. The code does not modify a file but it creates output that could be written to a new file. You will have to learn how to open a file for writing, too.

As Corion stated, you need to learn how to open a file for both reading and writing. In this post I personally went as far as to write my code to give an example of each.

i made some modification in reg exp in the code written by stevieb and it's working fine for this type of data data --- <script type="java/js"> foobie bletch </script> <%-- <script> zelgo mer </script> --> but problem is if i write endi script tag </script> not in the first column,it's not commenting or uncommenting that.

#!/usr/bin/perl

use warnings;
use strict;

open my $fh, '<', 'hii.txt' or die "Can't open the damn file for readi
+ng!: $!";

my @file_content;

while ( my $line = <$fh> ){
    chomp $line;

    if ( $line =~ /^<script(.*)>/ ){
        $line = "<%-- $line";
        push @file_content, "$line\n";
        next;
    }
    elsif ( $line =~ /^<\/script>$/ ){
        $line .= " -->";
        push @file_content, "$line\n";
        next;
   }
    elsif ( $line =~ /^<%--\s+<script(.*)>/ ){
        $line =~ s/^<%--\s+//;
        push @file_content, "$line\n";
        next;
    }
    elsif ( $line =~ /^<\/script>\s+-->/ ){
        $line =~ s/\s+-->//;
        push @file_content, "$line\n";
        next;
  }
    push @file_content, "$line\n";
}

close $fh;

open $fh, '>', 'hii.txt' or die "Can't open the damned file for writin
+g: $!";
print $fh @file_content;
close $fh;
[download]

<anyone plss write full working code as per my requirement.i need it urgently.thogh i'm going through docs of perl to learn some basic. the code should work on this type of data data -- <script type="main> </script> <script> </script>