1#ifndef foodaemonforkhfoo 2#define foodaemonforkhfoo 3 4/*** 5 This file is part of libdaemon. 6 7 Copyright 2003-2008 Lennart Poettering 8 9 libdaemon is free software; you can redistribute it and/or modify 10 it under the terms of the GNU Lesser General Public License as 11 published by the Free Software Foundation, either version 2.1 of the 12 License, or (at your option) any later version. 13 14 libdaemon is distributed in the hope that it will be useful, but 15 WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 Lesser General Public License for more details. 18 19 You should have received a copy of the GNU Lesser General Public 20 License along with libdaemon. If not, see 21 <http://www.gnu.org/licenses/>. 22***/ 23 24#include <sys/types.h> 25 26#ifdef __cplusplus 27extern "C" { 28#endif 29 30/** \mainpage libdaemon 31 * 32 * libdaemon 33 * 34 * For a brief explanation of libdaemons's purpose, have a look on the 35 * README file. Thank you! 36 * 37 */ 38 39/** \example testd.c 40 * This is an example for the usage of libdaemon 41 */ 42 43/** \file 44 * 45 * Contains an API for doing a daemonizing fork(). 46 * 47 * You may daemonize by calling daemon_fork(), a function similar to 48 * the plain fork(). If you want to return a return value of the 49 * initialization procedure of the child from the parent, you may use 50 * the daemon_retval_xxx() functions. 51 */ 52 53/** Does a daemonizing fork(). For the new daemon process STDIN, 54 * STDOUT, STDERR are connected to /dev/null, the process is a session 55 * leader, the current directory is changed to /, the umask is set to 56 * 777. 57 * @return On success, the PID of the child process is returned in the 58 * parent's thread of execution, and a 0 is returned in the child's 59 * thread of execution. On failure, -1 will be returned in the 60 * parent's context, no child process will be created, and errno will 61 * be set appropriately. 62 */ 63pid_t daemon_fork(void); 64 65/** Allocate and initialize resources required by the 66 * daemon_retval_xxx() functions. These functions allow the child to 67 * send a value to the parent after completing its initialisation. 68 * Call this in the parent before forking. 69 * @return zero on success, nonzero on failure. 70 */ 71int daemon_retval_init(void); 72 73/** Frees the resources allocated by daemon_retval_init(). This should 74 * be called if neither daemon_retval_wait() nor daemon_retval_send() 75 * is called in the current process. The resources allocated by 76 * daemon_retval_init() should be freed in both parent and daemon 77 * process. This may be achieved by using daemon_retval_wait() 78 * resp. daemon_retval_send(), or by using daemon_retval_done(). 79 */ 80void daemon_retval_done(void); 81 82/** Return the value sent by the child via the daemon_retval_send() 83 * function, but wait only the specified number of seconds before 84 * timing out and returning a negative number. Should be called just 85 * once from the parent process only. A subsequent call to 86 * daemon_retval_done() in the parent is ignored. 87 * 88 * @param timeout Thetimeout in seconds 89 * @return The integer passed daemon_retval_send() in the daemon process, or -1 on failure. 90 */ 91int daemon_retval_wait(int timeout); 92 93/** Send the specified integer to the parent process. Do not send -1 94 * because this signifies a library error. Should be called just once 95 * from the daemon process only. A subsequent call to 96 * daemon_retval_done() in the daemon is ignored. @param s The 97 * integer to pass to daemon_retval_wait() in the parent process 98 * @return Zero on success, nonzero on failure. 99 */ 100int daemon_retval_send(int s); 101 102/** This variable is defined to 1 iff daemon_close_all() and 103 * daemon_close_allv() are supported. 104 * @since 0.11 105 * @see daemon_close_all(), daemon_close_allv() */ 106#define DAEMON_CLOSE_ALL_AVAILABLE 1 107 108/** Close all file descriptors except those passed. List needs to be 109 * terminated by -1. FDs 0, 1, 2 will be kept open anyway. 110 * @since 0.11 111 * @see DAEMON_CLOSE_ALL_AVAILABLE */ 112int daemon_close_all(int except_fd, ...); 113 114/** Same as daemon_close_all but takes an array of fds, terminated by 115 * -1 116 * @since 0.11 117 * @see DAEMON_CLOSE_ALL_AVAILABLE */ 118int daemon_close_allv(const int except_fds[]); 119 120/** This variable is defined to 1 iff daemon_unblock_sigs() and 121 * daemon_unblock_sigsv() are supported. 122 * @since 0.13 123 * @see daemon_unblock_sigs(), daemon_unblock_sigsv()*/ 124#define DAEMON_UNBLOCK_SIGS_AVAILABLE 1 125 126/** Unblock all signals except those passed. List needs to be 127 * terminated by -1. 128 * @since 0.13 129 * @see DAEMON_UNBLOCK_SIGS_AVAILABLE */ 130int daemon_unblock_sigs(int except, ...); 131 132/** Same as daemon_unblock_sigs() but takes an array of signals, 133 * terminated by -1 134 * @since 0.13 135 * @see DAEMON_UNBLOCK_SIGS_AVAILABLE */ 136int daemon_unblock_sigsv(const int except[]); 137 138/** This variable is defined to 1 iff daemon_reset_sigs() and 139 * daemon_reset_sigsv() are supported. 140 * @since 0.13 141 * @see daemon_reset_sigs(), daemon_reset_sigsv() */ 142#define DAEMON_RESET_SIGS_AVAILABLE 1 143 144/** Reset all signal handlers except those passed. List needs to be 145 * terminated by -1. 146 * @since 0.13 147 * @see DAEMON_RESET_SIGS_AVAILABLE */ 148int daemon_reset_sigs(int except, ...); 149 150/** Same as daemon_reset_sigs() but takes an array of signals, 151 * terminated by -1 152 * @since 0.13 153 * @see DAEMON_RESET_SIGS_AVAILABLE */ 154int daemon_reset_sigsv(const int except[]); 155 156#ifdef __cplusplus 157} 158#endif 159 160#endif 161