lib/util/pidfile.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright (C) Jeremy Allison 2012.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #ifndef _SAMBA_PIDFILE_H_
  21 #define _SAMBA_PIDFILE_H_
  22
  23 /**
  24  * @file pidfile.h
  25  *
  26  * @brief PID file handling
  27  */
  28
  29 /**
  30  * @brief Create a PID file
  31  *
  32  * Opens file, locks it, and writes PID.  Returns EAGAIN if another
  33  * process has the PID file locked.  Use unlink(2) and
  34  * pidfile_fd_close() to remove the PID file.
  35  *
  36  * @param[in] path PID file name
  37  * @param[out] outfd File descriptor of open/locked PID file
  38  * @param[out] existing_pid Return existing PID on EAGAIN
  39  * @return 0 on success, errno on failure
  40  */
  41 int pidfile_path_create(
  42         const char *path, int *outfd, pid_t *existing_pid);
  43
  44 /**
  45  * @brief Unlock and close a PID file
  46  *
  47  * @param[in] fd File descriptor of open/locked PID file
  48  */
  49 void pidfile_fd_close(int fd);
  50
  51 /**
  52  * @brief Check a PID file
  53  *
  54  * PID file name is <piddir>/<name>.pid
  55  *
  56  * @param[in] piddir Directory for PID file
  57  * @param[in] name PID file process name
  58  * @return PID of active process, 0 if PID file missing/stale/error
  59  */
  60 pid_t pidfile_pid(const char *piddir, const char *name);
  61
  62 /**
  63  * @brief Create a PID file
  64  *
  65  * Leave PID file open/locked on success, exit on failure.  On
  66  * success, use pidfile_unlink() to remove PID file before exiting.
  67  *
  68  * PID file name is <piddir>/<name>.pid
  69  *
  70  * @param[in] piddir Directory for PID file
  71  * @param[in] name PID file process name
  72  */
  73 void pidfile_create(const char *piddir, const char *name);
  74
  75 /**
  76  * @brief Remove a PID file
  77  *
  78  * PID file name is <piddir>/<name>.pid
  79  *
  80  * @param[in] piddir Directory for PID file
  81  * @param[in] name PID file process name
  82  */
  83 void pidfile_unlink(const char *piddir, const char *name);
  84
  85 #endif