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libite

    1: /*	$OpenBSD: pidfile.c,v 1.11 2015/06/03 02:24:36 millert Exp $	*/
    2: /*	$NetBSD: pidfile.c,v 1.4 2001/02/19 22:43:42 cgd Exp $	*/
    3: 
    4: /*-
    5:  * Copyright (c) 1999 The NetBSD Foundation, Inc.
    6:  * All rights reserved.
    7:  *
    8:  * This code is derived from software contributed to The NetBSD Foundation
    9:  * by Jason R. Thorpe.
   10:  *
   11:  * Redistribution and use in source and binary forms, with or without
   12:  * modification, are permitted provided that the following conditions
   13:  * are met:
   14:  * 1. Redistributions of source code must retain the above copyright
   15:  *    notice, this list of conditions and the following disclaimer.
   16:  * 2. Redistributions in binary form must reproduce the above copyright
   17:  *    notice, this list of conditions and the following disclaimer in the
   18:  *    documentation and/or other materials provided with the distribution.
   19:  *
   20:  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   21:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   22:  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   23:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   24:  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   25:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   26:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   27:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   28:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   29:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   30:  * POSSIBILITY OF SUCH DAMAGE.
   31:  */
   32: 
   33: #include <sys/types.h>
   34: #include <errno.h>
   35: #include <paths.h>
   36: #include <stdio.h>
   37: #include <stdlib.h>
   38: #include <unistd.h>
   39: 
   40: #ifndef pidfile
   41: static char *pidfile_path = NULL;
   42: static pid_t pidfile_pid;
   43: 
   44: static void pidfile_cleanup(void);
   45: 
   46: const  char *__pidfile_name = NULL;
   47: extern char *__progname;
   48: 
   49: int
   50: pidfile(const char *basename)
   51: {
   52: 	int save_errno;
   53: 	pid_t pid;
   54: 	FILE *f;
   55: 
   56: 	if (basename == NULL)
   57: 		basename = __progname;
   58: 
   59: 	if (pidfile_path != NULL) {
   60: 		free(pidfile_path);
   61: 		pidfile_path = NULL;
   62: 		__pidfile_name = NULL;
   63: 	}
   64: 
   65: 	/* _PATH_VARRUN includes trailing / */
   66: 	if (asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename) == -1)
   67: 		return (-1);
   68: 
   69: 	if ((f = fopen(pidfile_path, "w")) == NULL) {
   70: 		save_errno = errno;
   71: 		free(pidfile_path);
   72: 		pidfile_path = NULL;
   73: 		errno = save_errno;
   74: 		return (-1);
   75: 	}
   76: 
   77: 	pid = getpid();
   78: 	if (fprintf(f, "%ld\n", (long)pid) <= 0 || fflush(f) != 0) {
   79: 		save_errno = errno;
   80: 		(void) fclose(f);
   81: 		(void) unlink(pidfile_path);
   82: 		free(pidfile_path);
   83: 		pidfile_path = NULL;
   84: 		errno = save_errno;
   85: 		return (-1);
   86: 	}
   87: 	(void) fclose(f);
   88: 
   89: 	/*
   90: 	 * LITE extension, no need to set up another atexit() handler
   91: 	 * if user only called us to update the mtime of the PID file
   92: 	 */
   93: 	if (pidfile_pid == pid)
   94: 		return (0);
   95: 
   96: 	pidfile_pid = pid;
   97: 	if (atexit(pidfile_cleanup) < 0) {
   98: 		save_errno = errno;
   99: 		(void) unlink(pidfile_path);
  100: 		free(pidfile_path);
  101: 		pidfile_path = NULL;
  102: 		pidfile_pid = 0;
  103: 		errno = save_errno;
  104: 		return (-1);
  105: 	}
  106: 	__pidfile_name = pidfile_path;
  107: 
  108: 	return (0);
  109: }
  110: 
  111: static void
  112: pidfile_cleanup(void)
  113: {
  114: 
  115: 	if (pidfile_path != NULL && pidfile_pid == getpid())
  116: 		(void) unlink(pidfile_path);
  117: }
  118: #endif