I tried this with constraints: I didn't want to use -i nor $^I.

Requirements:

File::Inplace
File::Flock.

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]

abc.txt:

hello
[download]

adc.txt:

jello
[download]

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