/ 
Sys-Cmd-v0.986.3
River stage one • 2 direct dependents • 2 total dependents
/ Sys::Cmd::Process

NAME

Sys::Cmd::Process - process interaction object for Sys::Cmd

VERSION

v0.986.3 (2025-12-11)

SYNOPSIS

use Sys::Cmd qw[spawn];

my $proc = spawn(
    '/usr/bin/cat', '--number',
    {
        dir   => '/',
        input => "x\ny\nz\n",
    }
);

while ( my $line = $proc->stdout->getline ) {
    print $line;
}

my @errors = $proc->stderr->getlines;
$proc->wait_child() or warn $proc->status;

# Or manually read process termination information
$proc->exit();          # exit status
$proc->signal();        # signal
$proc->core();          # core dumped? (boolean)

DESCRIPTION

The Sys::Cmd::Process class is used by Sys::Cmd to represent a running process. It holds Input/Output file handles and a few methods for finalising the process and obtaining exit information.

Process objects come with the following read-only attributes:

cmdline() -> @list | $string

In array context returns a list of the command and its arguments. In scalar context returns a string of the command and its arguments joined together by spaces.

pid() -> $int

The command's process ID.

stdin() -> IO::Handle

The command's STDIN file handle, based on IO::Handle so you can call print() etc methods on it. Autoflush is automatically enabled on this handle.

stdout() -> IO::Handle

The command's STDOUT file handle, based on IO::Handle so you can call getline() etc methods on it.

stderr() -> IO::Handle

The command's STDERR file handle, based on IO::Handle so you can call getline() etc methods on it.

When no more interaction with the process is required, the following methods are used for cleanup:

close()

Close the remaining open filehandles to the child process.

wait_child() -> $bool

Wait for the child process to finish using waitpid and collect the exit status. Returns true if the child terminated normally.

After wait_child has been called the following attributes are also valid:

core() -> $bool

A boolean indicating if the process core was dumped.

exit() -> $int

The command's exit value.

signal() -> $int

The signal number (if any) that terminated the command.

status() -> $str

A description of the process state. Sys::Cmd::Process sets it to a string starting with one of the following:

  • Running - set at creation time

  • Terminated - normal process exit

  • Non-zero exit - unusual process exit

  • Killed - termination via signal

This attribute can be set by the caller if desired, but note that wait_child() overwrites it.

AUTHOR

Mark Lawrence <mark@rekudos.net>

COPYRIGHT AND LICENSE

Copyright 2011-2025 Mark Lawrence <mark@rekudos.net>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.