Class Daemons::PidFile
In: lib/daemons/pidfile.rb
Parent: Pid

What is a Pid-File?

A Pid-File is a file containing the process identification number (pid) that is stored in a well-defined location of the filesystem thus allowing other programs to find out the pid of a running script.

Daemons needs the pid of the scripts that are currently running in the background to send them so called signals. Daemons uses the TERM signal to tell the script to exit when you issue a stop command.

How does a Pid-File look like?

Pid-Files generated by Daemons have to following format:

  <scriptname>.rb<number>.pid

(Note that <number> is omitted if only one instance of the script can run at any time)

Each file just contains one line with the pid as string (for example 6432).

Where are the Pid-Files stored?

Daemons is configurable to store the Pid-Files relative to three different locations:

  1. in a directory relative to the directory where the script (the one that is supposed to run as a daemon) resides (:script option for :dir_mode)
  2. in a directory given by :dir (:normal option for :dir_mode)
  3. in the preconfigured directory /var/run (:system option for :dir_mode)

Methods

cleanup   exist?   existing   filename   find_files   new   pid   pid=  

Attributes

dir  [R] 
multiple  [R] 
number  [R] 
progname  [R] 

Public Class methods

Public Instance methods

[Validate]