pidfilefn.c File Reference

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>

Include dependency graph for pidfilefn.c:

Functions
char *	chomp (char *str)
	Perl like chomp function, chop off last char(s) if newline. More...
pid_t	pidfile_read (const char *pidfile)
	Reads a PID value from a pidfile. More...
pid_t	pidfile_poll (const char *pidfile)
	Poll for the existence of a pidfile and return PID. More...
int	pidfile_signal (const char *pidfile, int signal)
	Send signal to a PID and cleanup pidfile afterwards. More...

Detailed Description

Author

Joachim Wiberg

Date

2009-2021

Copyright

ISC License

Function Documentation

chomp()

char* chomp

(

char *

str

)

Perl like chomp function, chop off last char(s) if newline.

Parameters

str	String to chomp

This function is like Perl chomp, but it's set to chop of all trailing newlines. Useful in combination with fgets().

Returns

str, or NULL with errno set, if str is not a valid pointer.

Exceptions

EINVAL

if the input argument is not a valid pointer.

pidfile_poll()

pid_t pidfile_poll

(

const char *

pidfile

)

Poll for the existence of a pidfile and return PID.

Parameters

pidfile

Path to pidfile to poll for

This function polls for the pidfile at pidfile for at most 5 seconds before timing out. If the file is created within that time span the file is read and its PID contents returned.

Returns

The PID read from pidfile, or zero on timeout.

pidfile_read()

pid_t pidfile_read

(

const char *

pidfile

)

Reads a PID value from a pidfile.

Parameters

pidfile

File containing PID, usually in /var/run/PROCNAME.pid

This function takes a pidfile and returns the PID found therein.

Returns

On invalid pidfile, -1 with errno set. If the pidfile is empty, or when its contents cannot be translated, this function returns zero (0), on success this function returns a PID value greater than one.

Note

PID 1 is reserved for the system init process.

Exceptions

EINVAL	on invalid pidfile, or
ENOENT	when pidfile does not exist.

pidfile_signal()

int pidfile_signal	(	const char *	pidfile,
		int	signal
	)

Send signal to a PID and cleanup pidfile afterwards.

Parameters

pidfile	File containing PID, usually in /var/run/PROCNAME.pid
signal	Signal to send to PID found in pidfile.

If signal is any of SIGTERM or SIGKILL, or if kill(2) returns -1, the pidfile is removed.

Returns

POSIX OK(0) on success, non-zero otherwise.