#!/usr/bin/perl -w      

  

use strict;


my $SCU='C:/Users/name/Desktop/a.txt';


open(FILE, "<$SCU") || die "File not found";

my @lines = <FILE>;

close(FILE);


my @newlines;

foreach(@lines) {
 
  $_ =~ s/<ABCD>/xyz/g;
 
  push(@newlines,$_);
}


open(FILE, "$SCU") || die "File not found";

print FILE @newlines;

close(FILE);