---
name: "File::Pid"
section: "3pm"
platform: "linux"
package: "libfile-pid-perl"
version: "1.01-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/File::Pid"
---

# File::Pid(3pm)

Pid File Manipulation

## NAME

File::Pid - Pid File Manipulation

## SYNOPSIS

```
  use File::Pid;

  my $pidfile = File::Pid->new({
    file => '/some/file.pid',
  });

  $pidfile->write;

  if ( my $num = $pidfile->running ) {
      die "Already running: $num\n";
  }
  $pidfile->remove;
```

## DESCRIPTION

This software manages a pid file for you. It will create a pid file, query the process within to discover if it's still running, and remove the pid file.

### new

```
  my $pidfile = File::Pid->new;
  my $thisfile = File::Pid->new({
    file => '/var/run/daemon.pid',
  });
  my $thisfileandpid = File::Pid->new({
    file => '/var/run/daemon.pid',
    pid  => '145',
  });
```

This constructor takes two optional parameters.

`"file"` - The name of the pid file to work on. If not specified, a pid file located in `"File::Spec->tmpdir()"` will be created that matches `"(File::Basename::basename($0))[0] . '.pid'"`. So, for example, if `$0` is *~/bin/sig.pl*, the pid file will be */tmp/sig.pl.pid*.

`"pid"` - The pid to write to a new pidfile. If not specified, `$$` is used when the pid file doesn't exist. When the pid file does exist, the pid inside it is used.

### file

```
  my $pidfile = $pidfile->file;
```

Accessor/mutator for the filename used as the pid file.

### pid

```
  my $pid = $pidfile->pid;
```

Accessor/mutator for the pid being saved to the pid file.

### write

```
  my $pid = $pidfile->write;
```

Writes the pid file to disk, inserting the pid inside the file. On success, the pid written is returned. On failure, `"undef"` is returned.

### running

```
  my $pid = $pidfile->running;
  die "Service already running: $pid\n" if $pid;
```

Checks to see if the pricess identified in the pid file is still running. If the process is still running, the pid is returned. Otherwise `"undef"` is returned.

### remove

```
  $pidfile->remove or warn "Couldn't unlink pid file\n";
```

Removes the pid file from disk. Returns true on success, false on failure.

### program\_name

This is a utility method that allows you to determine what `"File::Pid"` thinks the program name is. Internally this is used when no pid file is specified.

## SEE ALSO

perl.

## AUTHOR

Casey West, \<*casey@geeknest.com*\>.

## COPYRIGHT

```
  Copyright (c) 2005 Casey West.  All rights reserved.
  This module is free software; you can redistribute it and/or modify it
  under the same terms as Perl itself.
```