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dfork.h

dfork.h

Section: libdaemon (3) Updated: 2 Feb 2010
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NAME

dfork.h -

Contains an API for doing a daemonizing fork().

 

SYNOPSIS


#include <sys/types.h>

 

Defines


#define DAEMON_CLOSE_ALL_AVAILABLE 1
This variable is defined to 1 iff daemon_close_all() and daemon_close_allv() are supported.
#define DAEMON_UNBLOCK_SIGS_AVAILABLE 1
This variable is defined to 1 iff daemon_unblock_sigs() and daemon_unblock_sigsv() are supported.
#define DAEMON_RESET_SIGS_AVAILABLE 1
This variable is defined to 1 iff daemon_reset_sigs() and daemon_reset_sigsv() are supported.  

Functions


pid_t daemon_fork (void)
Does a daemonizing fork().
int daemon_retval_init (void)
Allocate and initialize resources required by the daemon_retval_xxx() functions.
void daemon_retval_done (void)
Frees the resources allocated by daemon_retval_init().
int daemon_retval_wait (int timeout)
Return the value sent by the child via the daemon_retval_send() function, but wait only the specified number of seconds before timing out and returning a negative number.
int daemon_retval_send (int s)
Send the specified integer to the parent process.
int daemon_close_all (int except_fd,...)
Close all file descriptors except those passed.
int daemon_close_allv (const int except_fds[])
Same as daemon_close_all but takes an array of fds, terminated by -1.
int daemon_unblock_sigs (int except,...)
Unblock all signals except those passed.
int daemon_unblock_sigsv (const int except[])
Same as daemon_unblock_sigs() but takes an array of signals, terminated by -1.
int daemon_reset_sigs (int except,...)
Reset all signal handlers except those passed.
int daemon_reset_sigsv (const int except[])
Same as daemon_reset_sigs() but takes an array of signals, terminated by -1.  

Detailed Description

Contains an API for doing a daemonizing fork().

You may daemonize by calling daemon_fork(), a function similar to the plain fork(). If you want to return a return value of the initialization procedure of the child from the parent, you may use the daemon_retval_xxx() functions.

Definition in file dfork.h.  

Define Documentation

 

#define DAEMON_CLOSE_ALL_AVAILABLE 1

This variable is defined to 1 iff daemon_close_all() and daemon_close_allv() are supported. Since:

0.11

See also:

daemon_close_all(), daemon_close_allv()

Definition at line 106 of file dfork.h.  

#define DAEMON_RESET_SIGS_AVAILABLE 1

This variable is defined to 1 iff daemon_reset_sigs() and daemon_reset_sigsv() are supported. Since:

0.13

See also:

daemon_reset_sigs(), daemon_reset_sigsv()

Definition at line 142 of file dfork.h.  

#define DAEMON_UNBLOCK_SIGS_AVAILABLE 1

This variable is defined to 1 iff daemon_unblock_sigs() and daemon_unblock_sigsv() are supported. Since:

0.13

See also:

daemon_unblock_sigs(), daemon_unblock_sigsv()

Definition at line 124 of file dfork.h.  

Function Documentation

 

int daemon_close_all (int except_fd, ...)

Close all file descriptors except those passed. List needs to be terminated by -1. FDs 0, 1, 2 will be kept open anyway.

Since:

0.11

See also:

DAEMON_CLOSE_ALL_AVAILABLE

Examples: testd.c.  

int daemon_close_allv (const int except_fds[])

Same as daemon_close_all but takes an array of fds, terminated by -1. Since:

0.11

See also:

DAEMON_CLOSE_ALL_AVAILABLE

 

pid_t daemon_fork (void)

Does a daemonizing fork(). For the new daemon process STDIN, STDOUT, STDERR are connected to /dev/null, the process is a session leader, the current directory is changed to /, the umask is set to 777.

Returns:

On success, the PID of the child process is returned in the parent's thread of execution, and a 0 is returned in the child's thread of execution. On failure, -1 will be returned in the parent's context, no child process will be created, and errno will be set appropriately.

Examples: testd.c.  

int daemon_reset_sigs (int except, ...)

Reset all signal handlers except those passed. List needs to be terminated by -1.

Since:

0.13

See also:

DAEMON_RESET_SIGS_AVAILABLE

Examples: testd.c.  

int daemon_reset_sigsv (const int except[])

Same as daemon_reset_sigs() but takes an array of signals, terminated by -1. Since:

0.13

See also:

DAEMON_RESET_SIGS_AVAILABLE

 

void daemon_retval_done (void)

Frees the resources allocated by daemon_retval_init(). This should be called if neither daemon_retval_wait() nor daemon_retval_send() is called in the current process. The resources allocated by daemon_retval_init() should be freed in both parent and daemon process. This may be achieved by using daemon_retval_wait() resp. daemon_retval_send(), or by using daemon_retval_done().

Examples: testd.c.  

int daemon_retval_init (void)

Allocate and initialize resources required by the daemon_retval_xxx() functions. These functions allow the child to send a value to the parent after completing its initialisation. Call this in the parent before forking.

Returns:

zero on success, nonzero on failure.

Examples: testd.c.  

int daemon_retval_send (int s)

Send the specified integer to the parent process. Do not send -1 because this signifies a library error. Should be called just once from the daemon process only. A subsequent call to daemon_retval_done() in the daemon is ignored.

Parameters:

s The integer to pass to daemon_retval_wait() in the parent process

Returns:

Zero on success, nonzero on failure.

Examples: testd.c.  

int daemon_retval_wait (int timeout)

Return the value sent by the child via the daemon_retval_send() function, but wait only the specified number of seconds before timing out and returning a negative number. Should be called just once from the parent process only. A subsequent call to daemon_retval_done() in the parent is ignored.

Parameters:

timeout Thetimeout in seconds

Returns:

The integer passed daemon_retval_send() in the daemon process, or -1 on failure.

Examples: testd.c.  

int daemon_unblock_sigs (int except, ...)

Unblock all signals except those passed. List needs to be terminated by -1.

Since:

0.13

See also:

DAEMON_UNBLOCK_SIGS_AVAILABLE

Examples: testd.c.  

int daemon_unblock_sigsv (const int except[])

Same as daemon_unblock_sigs() but takes an array of signals, terminated by -1. Since:

0.13

See also:

DAEMON_UNBLOCK_SIGS_AVAILABLE

 

Author

Generated automatically by Doxygen for libdaemon from the source code.


 

Index

NAME
SYNOPSIS
Defines
Functions
Detailed Description
Define Documentation
#define DAEMON_CLOSE_ALL_AVAILABLE 1
#define DAEMON_RESET_SIGS_AVAILABLE 1
#define DAEMON_UNBLOCK_SIGS_AVAILABLE 1
Function Documentation
int daemon_close_all (int except_fd, ...)
int daemon_close_allv (const int except_fds[])
pid_t daemon_fork (void)
int daemon_reset_sigs (int except, ...)
int daemon_reset_sigsv (const int except[])
void daemon_retval_done (void)
int daemon_retval_init (void)
int daemon_retval_send (int s)
int daemon_retval_wait (int timeout)
int daemon_unblock_sigs (int except, ...)
int daemon_unblock_sigsv (const int except[])
Author

This document was created by man2html, using the manual pages.
Time: 21:44:57 GMT, April 16, 2011