Here's a demo program showing how to write a cross-platform Windows/Linux background process spawner
#!/usr/bin/perl
use warnings;
use strict;
use Carp;
use Time::HiRes;
use POSIX 'setsid';
my $child_pid;
my $child_proc;
my $cmd = "./aprogram.exe";
my $debug = 1;
start_child();
sleep(5.0);
stop_child();
sub start_child
{
die "cannot execute cmd: $cmd" unless -x $cmd;
if ($^O eq 'MSWin32') # Windows
{
require Win32::Process;
Win32::Process::Create($child_proc, $cmd, $cmd, 0, 0, ".") || confess "Could not spawn child: $!";
$child_pid = $child_proc->GetProcessID();
}
else # Unix
{
$SIG{CHLD} = 'IGNORE';
$child_pid = fork();
unless (defined $child_pid)
{
confess "Could not spawn child (Unix): $!";
}
if ($child_pid == 0 ) # child
{
unless ($debug)
{
open STDIN, "<", "/dev/null" or die "Can't read /dev/null: $!";
open STDOUT, ">", "/dev/null" or die "Can't write /dev/null: $!";
}
setsid or warn "setsid cannot start a new session: $!";
unless ($debug)
{
open STDERR, '>&STDOUT' or die "Can't dup stdout: $!";
}
local $| = 1;
unless (exec($cmd))
{
confess "Could not start child: $cmd: $!";
CORE::exit(0);
}
}
# parent
$SIG{CHLD} = 'DEFAULT';
}
# catch early child exit, e.g. if program path is incorrect
sleep(1.0);
POSIX::waitpid(-1, POSIX::WNOHANG()); # clean up any defunct child process
if (kill(0,$child_pid))
{
print "Started child process id $child_pid\n";
}
else
{
warn "Child process exited quickly: $cmd: process $child_pid";
}
}
sub stop_child
{
if ($^O eq 'MSWin32') # Windows
{
Win32::Process::KillProcess($child_pid,0);
}
else # Unix
{
kill 9, $child_pid || warn "could not kill process $child_pid: $!";
}
print "Stopped child process id $child_pid\n";
}
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