Issue
I recently came across a file with the extension .pid and looked inside it but didn't find much. The href="https://web.archive.org/web/20170216075004/daemons.rubyforge.org/classes/Daemons/PidFile.html" rel="noreferrer">documentation says:
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.
Can anyone shed more light on this or guide me to details of what's contained in the pid file?
Solution
The pid files contains the process id (a number) of a given program. For example, Apache HTTPD may write its main process number to a pid file - which is a regular text file, nothing more than that - and later use the information there contained to stop itself. You can also use that information to kill the process yourself, using cat filename.pid | xargs kill
Answered By - Rafael Steil Answer Checked By - Mary Flores (WPSolving Volunteer)