/* $Id: pid.c,v 1.10 2005/05/08 04:32:44 reinelt Exp $ * * PID file handling * * Copyright (C) 1999, 2000 Michael Reinelt * * This file is part of LCD4Linux. * * LCD4Linux is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * LCD4Linux 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * * $Log: pid.c,v $ * Revision 1.10 2005/05/08 04:32:44 reinelt * CodingStyle added and applied * * Revision 1.9 2005/01/18 06:30:23 reinelt * added (C) to all copyright statements * * Revision 1.8 2004/06/26 12:04:59 reinelt * * uh-oh... the last CVS log message messed up things a lot... * * Revision 1.7 2004/06/26 09:27:21 reinelt * * added '-W' to CFLAGS * changed all C++ comments to C ones * cleaned up a lot of signed/unsigned mistakes * * Revision 1.6 2004/03/19 06:37:47 reinelt * asynchronous thread handling started * * Revision 1.5 2004/03/03 04:44:16 reinelt * changes (cosmetics?) to the big patch from Martin * hash patch un-applied * * Revision 1.4 2004/03/03 03:47:04 reinelt * big patch from Martin Hejl: * - use qprintf() where appropriate * - save CPU cycles on gettimeofday() * - add quit() functions to free allocated memory * - fixed lots of memory leaks * * Revision 1.3 2004/01/29 04:40:02 reinelt * every .c file includes "config.h" now * * Revision 1.2 2003/10/05 17:58:50 reinelt * libtool junk; copyright messages cleaned up * * Revision 1.1 2003/08/08 08:05:23 reinelt * added PID file handling * */ /* * exported functions: * * int pid_init (const char *pidfile) * returns 0 if PID file could be successfully created * returns PID of an already running process * returns -1 in case of an error * int pid_exit (const char *pidfile) * returns 0 if PID file could be successfully deleted * otherwise returns error from unlink() call * */ #include "config.h" #include #include #include #include #include #include #include #include #include #include "debug.h" #include "pid.h" #include "qprintf.h" #ifdef WITH_DMALLOC #include #endif int pid_init(const char *pidfile) { char tmpfile[256]; char buffer[16]; int fd, len, pid; qprintf(tmpfile, sizeof(tmpfile), "%s.%s", pidfile, "XXXXXX"); if ((fd = mkstemp(tmpfile)) == -1) { error("mkstemp(%s) failed: %s", tmpfile, strerror(errno)); return -1; } if (fchmod(fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) == -1) { error("fchmod(%s) failed: %s", tmpfile, strerror(errno)); close(fd); unlink(tmpfile); return -1; } qprintf(buffer, sizeof(buffer), "%d\n", (int) getpid()); len = strlen(buffer); if (write(fd, buffer, len) != len) { error("write(%s) failed: %s", tmpfile, strerror(errno)); close(fd); unlink(tmpfile); return -1; } close(fd); while (link(tmpfile, pidfile) == -1) { if (errno != EEXIST) { error("link(%s, %s) failed: %s", tmpfile, pidfile, strerror(errno)); unlink(tmpfile); return -1; } if ((fd = open(pidfile, O_RDONLY)) == -1) { if (errno == ENOENT) continue; /* pidfile disappared */ error("open(%s) failed: %s", pidfile, strerror(errno)); unlink(tmpfile); return -1; } len = read(fd, buffer, sizeof(buffer) - 1); if (len < 0) { error("read(%s) failed: %s", pidfile, strerror(errno)); unlink(tmpfile); return -1; } buffer[len] = '\0'; if (sscanf(buffer, "%d", &pid) != 1 || pid == 0) { error("scan(%s) failed.", pidfile); unlink(tmpfile); return -1; } if (pid == getpid()) { error("%s already locked by us. uh-oh...", pidfile); unlink(tmpfile); return 0; } if ((kill(pid, 0) == -1) && errno == ESRCH) { error("removing stale PID file %s", pidfile); if (unlink(pidfile) == -1 && errno != ENOENT) { error("unlink(%s) failed: %s", pidfile, strerror(errno)); unlink(tmpfile); return pid; } continue; } unlink(tmpfile); return pid; } unlink(tmpfile); return 0; } int pid_exit(const char *pidfile) { return unlink(pidfile); } ='n63' href='#n63'>63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144