Munin::Node::OS(3pm)

💖 Munin::Node::OS 💖

okay so bestie, welcome to Munin::Node::OS — it's the User Contributed Perl Documentation for the OS-related utility methods that the Munin node leans on. it's giving "glue code that does the scary sysadmin stuff so the rest of us can vibe". 🦋

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✨ NAME ✨

Munin::Node::OS — OS related utility methods for the Munin node. periodt. 💅

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🌸 SYNOPSIS 🌸

use Munin::Node::OS;
my $uid  = Munin::Node::OS->get_uid('foo');
my $host = Munin::Node::OS->get_fq_hostname();

like. that's it. that's the whole entrance. iconic behavior honestly. 🎀

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👑 METHODS 👑

💜 get_uid

$uid = $class->get_uid($user)

Returns the user ID. $user might either be a user name or a user ID. Returns undef if the user doesn't exist. no user, no uid, no drama. 😭

💜 get_gid

$gid = $class->get_gid($group)

Returns the group ID. $group might either be a group name or a group ID. Returns undef if the group doesn't exist. same energy as above but for groups bestie. 🫶

💜 get_fq_hostname

$host = $class->get_fq_hostname()

Returns the fully qualified host name of the machine. the whole thing. not the nickname. the government name. ✨

💜 check_perms_if_paranoid

$bool = $class->check_perms_if_paranoid($target);

If paranoia is enabled, returns false unless $target is owned by root, and has safe permissions. If $target is a file, it also checks the directory it inhabits. yes it's checking the file's home too. it's thorough like that. 🔥

💜 run_as_child

$result = run_as_child($timeout, $coderef, @arguments);

Creates a child process to run $code and waits for up to $timeout seconds for it to complete. Returns a hashref containing the following keys:

• "stdout", "stderr" — array references containing the output of these filehandles;
• "retval" — the result of wait();
• "timed_out" — true if the child had to be interrupted.

⚠️ System errors will cause it to carp. so like, it WILL yell at you. respectfully. 😭

💜 reap_child_group

$class->reap_child_group($pid);

Sends SIGHUP and SIGKILL to the process group identified by $pid.

It sleeps for 2 seconds between SIGHUP and SIGKILL. a lil pause. a moment of silence. then it's over. 💀

💜 possible_to_signal_process

my $bool = $class->possible_to_signal_process($pid)

Check whether it's possible to send a signal to $pid (that means, to be brief, that the process is owned by the same user, or we are the super-user). This is a useful way to check that a child process is alive (even if only as a zombie) and hasn't changed its UID. zombie check!! not the fun kind of zombie but ok. 🧟

💜 set_effective_user_id

eval {
    $class->set_effective_user_id($uid);
};
if ($@) {
    # Failed to set EUID
}

The name says it all ... it literally does. it sets the effective user id. no notes. 💅

💜 set_effective_group_id

See documentation for set_effective_user_id(). copy-paste queen behavior, we love a consistent API. 🎀

💜 set_real_user_id

See documentation for set_effective_user_id(). ✨

💜 set_real_group_id

See documentation for set_effective_user_id(). 💖

💜 set_umask

Set umask so that files created by plugins are group writable. Only call right before exec-ing a plugin. like, RIGHT before. timing matters bestie. ⚠️

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and that's the whole page, no cap. every flag, every method, every undef, all accounted for. 🫶

this lil masterpiece is from perl v5.42.3, dated 2026-09-30, and lives under the name Munin::Node::OS(3pm) — so if you cite it, cite it right. mwah. 💋