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#ifndef foodaemonforkhfoo
#define foodaemonforkhfoo
/* $Id$ */
/*
* This file is part of libdaemon.
*
* libdaemon is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* libdaemon is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with libdaemon; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <sys/types.h>
#ifdef __cplusplus
extern "C" {
#endif
/** \mainpage libdaemon
*
* libdaemon
*
* For a brief explanation of libdaemons's purpose, have a look on the
* README file. Thank you!
*
*/
/** \example testd.c
* This is an example for the usage of libdaemon
*/
/** \file
*
* 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.
*/
/** 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.
* @return 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.
*/
pid_t daemon_fork(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.
* @return zero on success, nonzero on failure.
*/
int daemon_retval_init(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().
*/
void daemon_retval_done(void);
/** 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.
*
* @param timeout Thetimeout in seconds
* @return The integer passed daemon_retval_send() in the daemon process, or -1 on failure.
*/
int daemon_retval_wait(int timeout);
/** 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. @param s The
* integer to pass to daemon_retval_wait() in the parent process
* @return Zero on success, nonzero on failure.
*/
int daemon_retval_send(int s);
#ifdef __cplusplus
}
#endif
#endif
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