#!/bin/perl

local $^I = "sub/.bak";
local @ARGV = ('/home/antony/perl/l.pl');

while ( <> ) {
        s/instance/NEW_PATTERN/;
        print;
}


##</code><code>##

Error:
Can't rename /home/antony/perl/l.pl to /home/antony/perl/l.plsub/.bak: No such file or directory, skipping file at l line 6.