daemonize.c File Reference

Daemonize the program. More...

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include "defaults.h"
#include "log.h"

Include dependency graph for daemonize.c:

Functions
static void	check_pidfile (const char *pidfile)
	Exit if the process referenced by pidfile is running. More...
static char *	getpwd (void)
	Get the current working directory. More...
static pid_t	write_pidfile (const char *pidfile, pid_t pid)
	Write a PID file. More...
void	daemonize (const char *pidfile)
	Daemonize the program. More...

Variables
char **	environ

Detailed Description

Daemonize the program.

Function Documentation

static void check_pidfile ( const char *  pidfile )

static

Exit if the process referenced by pidfile is running.

Parameters

pidfile

Path to PID file

static char * getpwd ( void  )

static

Get the current working directory.

Returns

Absolute path to the current working directory if successful, or NULL if unsuccessful

Note

Like get_current_dir_name(3)

If successful, caller is responsible for free(3)ing the result

See also

get_current_dir_name(3)

static pid_t write_pidfile ( const char *  pidfile, pid_t  pid  )

static

Write a PID file.

Attempts to do so "atomically" as per daemon(7). Does not write PID file if the file referenced by pidfile already exists, or the process ID referenced by the file is in use by a running process.

Parameters

pidfile	Path to PID file
pid	A PID

Returns

The PID actually written to the PID file

Note

Result should be equal to

Exits if unsuccessful

void daemonize

(

const char *

pidfile

)

Daemonize the program.

Attempts to do so in the manner described in daemon(7) - forks twice, with the parent writing the PID of the second child to a PID file before exiting. The daemon child also adds $PWD to its environment, in case any scripts it executes require it.

Parameters

pidfile

Path to PID file

Note

Exits if unsuccessful

Variable Documentation

char** environ