1/* Copyright (C) 1996 N.M. Maclaren 2 Copyright (C) 1996 The University of Cambridge 3 4This includes code that really should have been part of ANSI/ISO C, but was 5left out for historical reasons (despite requests to define ftty), plus 6the get_lock() and log_message() functions. 7*/ 8 9#include "header.h" 10 11#include <sys/types.h> 12#include <unistd.h> 13#include <syslog.h> 14#include <signal.h> 15 16#define UNIX 17#include "kludges.h" 18#undef UNIX 19 20 21void do_nothing (int seconds) { 22 23/* Wait for a fixed period, possibly uninterruptibly. This should not wait 24for less than the specified period, if that can be avoided. */ 25 26 sleep((unsigned int)(seconds+2)); /* +2 is enough for POSIX */ 27} 28 29 30 31int ftty (FILE *file) { 32 33/* Return whether the file is attached to an interactive device. */ 34 35 return isatty(fileno(file)); 36} 37 38 39 40void set_lock (int lock) { 41 42/* Check that we have enough privileges to reset the time and that no other 43updating msntp process is running, but don't bother with fancy interlocking. 44This function is really only to permit the daemon mode to be restarted in a 45cron job and improve the diagnostics; it can be replaced by a 'return' 46statement if it causes implementation difficulties. Note that there is little 47point in clearing the lock under Unix, but do so anyway. */ 48 49 FILE *file; 50 long pid; 51 52 if (lockname == NULL || lockname[0] == '\0') return; 53 if (lock) { 54 errno = 0; 55 if ((file = fopen(lockname,"r")) != NULL && 56 fscanf(file,"%ld",&pid) == 1 && kill(pid,0) == 0) { 57 if (verbose || isatty(STDIN_FILENO) || isatty(STDOUT_FILENO)) 58 fatal(0,"another msntp process is currently running",NULL); 59 else 60 fatal(0,NULL,NULL); 61 } 62 if (file != NULL) fclose(file); 63 errno = 0; 64 if ((file = fopen(lockname,"w")) == NULL || 65 fprintf(file,"%ld\n",(long)getpid()) <= 0 || 66 ferror(file) || fclose(file) != 0) 67 fatal(1,"unable to write PID to %s",lockname); 68 adjust_time(0.0,1,0.0); 69 } else { 70 errno = 0; 71 if (remove(lockname) != 0) 72 fatal(1,"unable to remove the msntp lockname %s",lockname); 73 } 74} 75 76 77 78/* 79 * Log a message, crudely. 80 * This is used in only one place, but could be used more widely. 81 */ 82 83void 84log_message (const char *message) 85{ 86 87 syslog( 88#ifdef LOG_DAEMON 89 LOG_DAEMON | 90#endif 91 LOG_WARNING, "%s", message); 92} 93