syslog.c
上传用户:tsgydb
上传日期:2007-04-14
资源大小:10674k
文件大小:5k
- /*
- * Copyright (c) 1983, 1988 Regents of the University of California.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms are permitted
- * provided that this notice is preserved and that due credit is given
- * to the University of California at Berkeley. The name of the University
- * may not be used to endorse or promote products derived from this
- * software without specific prior written permission. This software
- * is provided ``as is'' without express or implied warranty.
- */
- #if defined(LIBC_SCCS) && !defined(lint)
- static char sccsid[] = "@(#)syslog.c 5.14 (Berkeley) 5/20/88";
- #endif /* LIBC_SCCS and not lint */
- /*
- * SYSLOG -- print message on log file
- *
- * This routine looks a lot like printf, except that it
- * outputs to the log file instead of the standard output.
- * Also:
- * adds a timestamp,
- * prints the module name in front of the message,
- * has some other formatting types (or will sometime),
- * adds a newline on the end of the message.
- *
- * The output of this routine is intended to be read by /etc/syslogd.
- *
- * Author: Eric Allman
- * Modified to use UNIX domain IPC by Ralph Campbell
- * Modified for pthreads and made more POSIX-compliant by Greg Hudson
- */
- #include <pthread.h>
- #include <sys/types.h>
- #include <sys/socket.h>
- #include <signal.h>
- #include <stdio.h>
- #include <stdarg.h>
- #include <string.h>
- #include <fcntl.h>
- #include <netdb.h>
- #include <unistd.h>
- #include <errno.h>
- #include <syslog.h>
- int socket();
- char *strerror(int); /* For systems that don't prototype it */
- #define MAXLINE 1024 /* max message size */
- #define PRIFAC(p) (((p) & LOG_FACMASK) >> 3)
- /* XXX should be in <syslog.h> */
- #define IMPORTANT LOG_ERR
- static void basic_init(void);
- static char _log_name[] = "/dev/log";
- static char ctty[] = "/dev/console";
- static int LogFile = -1; /* fd for log */
- static int LogStat = 0; /* status bits, set by openlog() */
- static char *LogTag = "syslog"; /* string to tag the entry with */
- static int LogMask = 0xff; /* mask of priorities to be logged */
- static int LogFacility = LOG_USER; /* default facility code */
- static pthread_mutex_t basic_init_lock = PTHREAD_MUTEX_INITIALIZER;
- static struct sockaddr SyslogAddr; /* AF_UNIX address of local logger */
- static void basic_init()
- {
- pthread_mutex_lock(&basic_init_lock);
- if (LogFile < 0)
- openlog(LogTag, LogStat | LOG_NDELAY, 0);
- pthread_mutex_unlock(&basic_init_lock);
- }
- void syslog(int pri, char *fmt, ...)
- {
- va_list args;
- va_start(args, fmt);
- vsyslog(pri, fmt, args);
- va_end(args);
- }
- void vsyslog(int pri, char *fmt, va_list args)
- {
- char buf[MAXLINE + 1], outline[MAXLINE + 1];
- register char *b, *f, *o;
- register int c;
- time_t now;
- int olderrno = errno, fd;
- /* Do a basic initialization if user didn't call openlog(). */
- if (LogFile < 0)
- basic_init();
- /* see if we should just throw out this message */
- if ((unsigned) PRIFAC(pri) >= LOG_NFACILITIES ||
- (LOG_MASK(pri & LOG_PRIMASK) & LogMask) == 0 ||
- (pri &~ (LOG_PRIMASK|LOG_FACMASK)) != 0)
- return;
- /* set default facility if none specified */
- if ((pri & LOG_FACMASK) == 0)
- pri |= LogFacility;
- /* build the message */
- o = outline;
- (void)sprintf(o, "<%d>", pri);
- o += strlen(o);
- time(&now);
- (void)sprintf(o, "%.15s ", ctime(&now) + 4);
- o += strlen(o);
- if (LogTag) {
- strcpy(o, LogTag);
- o += strlen(o);
- }
- if (LogStat & LOG_PID) {
- (void)sprintf(o, "[%d]", getpid());
- o += strlen(o);
- }
- if (LogTag) {
- strcpy(o, ": ");
- o += 2;
- }
- b = buf;
- f = fmt;
- while ((c = *f++) != ' ' && c != 'n' && b < &buf[MAXLINE]) {
- char *strerror();
- if (c != '%') {
- *b++ = c;
- continue;
- }
- if ((c = *f++) != 'm') {
- *b++ = '%';
- *b++ = c;
- continue;
- }
- strcpy(b, strerror(olderrno));
- b += strlen(b);
- }
- *b++ = 'n';
- *b = ' ';
- vsprintf(o, buf, args);
- c = strlen(outline);
- if (c > MAXLINE)
- c = MAXLINE;
- /* output the message to the local logger */
- if (sendto(LogFile, outline, c, 0, &SyslogAddr, sizeof SyslogAddr) >= 0)
- return;
- if (!(LogStat & LOG_CONS))
- return;
- /* output the message to the console */
- fd = open(ctty, O_WRONLY);
- alarm(0);
- strcat(o, "r");
- o = strchr(outline, '>') + 1;
- write(fd, o, c + 1 - (o - outline));
- close(fd);
- }
- /*
- * OPENLOG -- open system log
- */
- void openlog(char *ident, int logstat, int logfac)
- {
- int flags;
- if (ident != NULL)
- LogTag = ident;
- LogStat = logstat;
- if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
- LogFacility = logfac;
- if (LogFile >= 0)
- return;
- SyslogAddr.sa_family = AF_UNIX;
- strncpy(SyslogAddr.sa_data, _log_name, sizeof SyslogAddr.sa_data);
- if (LogStat & LOG_NDELAY) {
- LogFile = socket(AF_UNIX, SOCK_DGRAM, 0);
- flags = fcntl(LogFile, F_GETFD);
- fcntl(LogFile, F_SETFD, flags & O_NONBLOCK);
- }
- }
- /*
- * CLOSELOG -- close the system log
- */
- void closelog()
- {
- (void) close(LogFile);
- LogFile = -1;
- }
- /*
- * SETLOGMASK -- set the log mask level
- */
- int setlogmask(int pmask)
- {
- int omask;
- omask = LogMask;
- if (pmask != 0)
- LogMask = pmask;
- return (omask);
- }