一个不错的记录Log的程序

 转自：http://topic.csdn.net/u/20111213/09/03262588-49b4-44ef-b6aa-6f15a5efb4ac.html

由zhao4zhong1提供：

 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef WIN32
#include <windows.h>
#include <io.h>
#else
#include <unistd.h>
#include <sys/time.h>
#include <pthread.h>
#define  CRITICAL_SECTION   pthread_mutex_t
#define  _vsnprintf         vsnprintf
#endif
//Log{
#define MAXLOGSIZE 100000000
#define ARRSIZE(x) (sizeof(x)/sizeof(x[0]))
#include <time.h>
#include <stdarg.h>
char logfilename1[]="MyLog1.log";
char logfilename2[]="MyLog2.log";
char logstr[16000];
char datestr[16];
char timestr[16];
char ms10[3];
CRITICAL_SECTION cs_log;
FILE *flog;
int centisec() {
#ifdef WIN32
 return ((GetTickCount()%1000L)/10)%100;
#else
 struct timeval tv;

 if (!gettimeofday(&tv,NULL)) {
  return ((tv.tv_usec%1000000L)/10000)%100;
 } else {
  return 0;
 }
#endif
}
#ifdef WIN32
void Lock(CRITICAL_SECTION *l) {
 EnterCriticalSection(l);
}
void Unlock(CRITICAL_SECTION *l) {
 LeaveCriticalSection(l);
}
#else
void Lock(CRITICAL_SECTION *l) {
 pthread_mutex_lock(l);
}
void Unlock(CRITICAL_SECTION *l) {
 pthread_mutex_unlock(l);
}
#endif
void LogV(const char *pszFmt,va_list argp) {
 struct tm *now;
 time_t aclock;

 if (NULL==pszFmt||0==pszFmt[0]) return;
 if (-1==_vsnprintf(logstr,ARRSIZE(logstr),pszFmt,argp)) logstr[ARRSIZE(logstr)-1]=0;
 time(&aclock);
 now=localtime(&aclock);
 sprintf(datestr,"%04d-%02d-%02d",now->tm_year+1900,now->tm_mon+1,now->tm_mday);
 sprintf(timestr,"%02d:%02d:%02d",now->tm_hour     ,now->tm_min  ,now->tm_sec );
 sprintf(ms10,"%02d",centisec());
 printf("%s %s.%s %s",datestr,timestr,ms10,logstr);
 flog=fopen(logfilename1,"a");
 if (NULL!=flog) {
  fprintf(flog,"%s %s.%s %s",datestr,timestr,ms10,logstr);
  if (ftell(flog)>MAXLOGSIZE) {
   fclose(flog);
   if (rename(logfilename1,logfilename2)) {
    remove(logfilename2);
    rename(logfilename1,logfilename2);
   }
   flog=fopen(logfilename1,"a");
   if (NULL==flog) return;
  }
  fclose(flog);
 }
}
void Log(const char *pszFmt,...) {
 va_list argp;

 Lock(&cs_log);
 va_start(argp,pszFmt);
 LogV(pszFmt,argp);
 va_end(argp);
 Unlock(&cs_log);
}
//Log}
int main(int argc,char * argv[]) {
 int i;
#ifdef WIN32
 InitializeCriticalSection(&cs_log);
#else
 pthread_mutex_init(&cs_log,NULL);
#endif
 for (i=0;i<10000;i++) {
  Log("This is a Log %04d from FILE:%s LINE:%d\n",i, __FILE__, __LINE__);
 }
#ifdef WIN32
 DeleteCriticalSection(&cs_log);
#else
 pthread_mutex_destroy(&cs_log);
#endif
 return 0;
}