Knife.pm

package Proc::Knife;

use strict;
use warnings;
use v5.36;
use Exporter 'import';
use POSIX ":sys_wait_h";

our @EXPORT_OK = qw(knife);

sub knife {
    my @cmd = @{shift()};
    my %opts = @_;
    my $pid = fork // die "A: Can't fork child: $!";
    if ($pid == 0) {
        $pid = fork // die "B: Can't fork grandchild: $!";
        if ($pid == 0) {
            exec @cmd;
            die "C: Can't exec \@cmd: $!";
        }
        exit;
    }
    waitpid $pid, 0;
}

1;

=head1 NAME

Proc::Knife - Spawn and free child processes by double-forking

=head1 SYNOPSIS

  use Proc::Knife;
  knife(["somecommand", "somearg"]);

=head1 DESCRIPTION

The C<knife> function double forks and cleans up (waitpid) the first child, so the grandchild is free 
(severed at its umbilical cord) from the parent. This allows the grandchild process to run independently 
without becoming a zombie. This module does not manage stdin/out/err.

See L<Proc::Daemon> if you require more control over the process handling.

=head1 FUNCTIONS

=head2 knife

  knife($command_array_ref);

Executes the commands specified in C<$command_array_ref>. This function will double fork to ensure that 
the grandchild process is entirely detached from the parent process.

=head1 SEE ALSO

L<Proc::Daemon>

=head1 AUTHOR

Jaggz H. <jaggz.h {over at} gmail.com>

=cut