I'm not able to change that at present for reasons I can't go into.

How do I survive jumping out of a highflying aircraft without using a free, easily available parachute? Sigh. Sounds more like a political problem than a perl problem.

Anyway. Look in "perldoc perlrun" under -i to see the demo equivalent of inplace editing, then reimplement including the desired changes. You're stuffing the filename into @ARGV not passing it in from the command line, and there's only one at a time, so those aren't a problem. I don't really see why you are so tied to the default implicit behaviors.

Requirements:

A dir "in_place"
A file "abc.txt".
A file "adc.txt".
Both files should be in the dir "in_place".

#!/usr/bin/perl

use strict;
use warnings;
use File::Copy;
use File::Inplace;
use File::Spec;
use File::Flock;

my $dir = '/root/Desktop/in_place';
my $data_dir = sub { File::Spec->catfile($dir, shift); };
my $abc_file = "/root/Desktop/in_place/abc.txt";
my $adc_file = "/root/Desktop/in_place/adc.txt";

lock($abc_file, 'shared', 'nonblocking');
lock($adc_file, 'shared', 'nonblocking');

my $edit = new File::Inplace(file => $data_dir->("abc.txt"), suffix =>
+ ".log");
quick_change($edit, hello => 'jello');
$edit->commit;

my $lock = File::Flock->new($edit);
lock($lock, 'abc.txt.log');
lock_rename($lock, 'abc.txt.log');
unlock('abc.txt.log');

sub quick_change {
    my $edit = shift;
    my $from = shift;
    my $to   = shift; 
    
    while ($edit->has_lines) {
        my $line = $edit->next_line;
        if ($line eq $from) {
            $edit->replace_line($to);
        }
     }
}
[download]

hello
[download]

jello
[download]

I had a go at doing it this way using a semaphore file. But I'm running into problems and can't figure out what is wrong.

sub filelock;

filelock "lockit";

Do the inplace edit stuff here

filelock "unlock";

sub filelock {

 if ( @_ eq "lockit" ) {
         open(LCK,">abc.lock") or die "Can't open abc.lock: $! \n";
         unless (flock LCK, LOCK_EX) {
                warn "Waiting to obtain lock on LCK ....\n";
                flock(LCK, LOCK_EX) or die "Cannot lock semaphore file
+ - $!\n";
         }
 }

 if ( @_ eq "unlock" ) {
        close(LCK)
 }

}
[download]

The problem is that it's not recognising "lockit" or "unlock" when the filelock subroutine is called. Even though when I print out @_ it displays "lockit" or "unlock" accordingly. What am I doing wrong ?

fixed by adding this

my $lockopt = shift;

if ( $lockopt eq "unlock") {
do stuff...
}
[download]

Being new to perl there's undoubtedly a better way of doing this !