Question

我正在寻找一种方法将当前日期和时间添加到我打开的日志文件中现在我正在使用：

fopen("/var/log/SA_TEST","w");

如何制作

fopen("/var/log/SA_TEST_DATE_AND_TIME","w");

很多（在c）

Answer 1

strftime可用于格式化日期：

#include <time.h>

char filename[40];
struct tm *timenow;

time_t now = time(NULL);
timenow = gmtime(&now);

strftime(filename, sizeof(filename), "/var/log/SA_TEST_%Y-%m-%d_%H:%M:%S", timenow);

fopen(filename,"w");

您可以根据strftime manual更改日期的时间格式。

您可以将时间戳用作紧凑格式＆＃39;结果只有time。

sprintf(filename, "/var/log/SA_TEST_%d", (int)now);

Answer 2

/* ctime example */
#include <stdio.h>      /* printf */
#include <time.h>       /* time_t, time, ctime */

int main ()
{
  time_t rawtime;
  char buffer [255];

  time (&rawtime);
  sprintf(buffer,"/var/log/SA_TEST_%s",ctime(&rawtime) );
// Lets convert space to _ in

char *p = buffer;
for (; *p; ++p)
{
    if (*p == ' ')
          *p = '_';
}



  printf("%s",buffer);
  fopen(buffer,"w");

  return 0;
}

输出

/var/log/SA_TEST_Wed_Jul_30_12:17:19_2014

Answer 3

  time_t rawtime;
  struct tm * timeinfo;
  char buffer [64];

  time (&rawtime);
  timeinfo = localtime (&rawtime);

  strftime (buffer,64,"/var/log/SA_TEST_%x_%X",timeinfo);//generate string SA_TEST_DATE_TIME
  fopen(buffer, "w");

参见： man strftime 对于格式，您可以获得时间和日期。

Answer 4

以下列方式使用sprintf

char date_time[30];   //Collect system date and time in this character array
char filename[40]
sprintf(filename, "/var/log/SA_TEST_%s", date_time);
fopen(filename,"w");

Answer 5

#include <stdio.h>
#include <time.h>
#include <stdlib.h>

int main(int argc, char* argv[]) {

    printf("Runfile: %s Date: %s Time : %s \n", __FILE__, __DATE__, __TIME__ );

    FILE     *fptr;
    char     *fmode, filename[255], strtime_sec[20], strtime_nsec[20];
    struct   tm* tm;            
    struct   timespec ts;
    time_t   now;

    now = time(NULL);          // get current time
    tm  = localtime(&now);     // get time structure

    // Get current time from system clock    
    clock_gettime(CLOCK_REALTIME, &ts);

    // Convert integer times to strings using snprintf()
    snprintf(strtime_sec,  20, "%d",  ts.tv_sec);
    snprintf(strtime_nsec, 20, "%ld", ts.tv_nsec);

    // Generate dynamic filename and set filemode
    sprintf(filename, "file_%04d%02d%02d_%s.txt", tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday, strtime_sec);
    fmode = "a";       

    // Open file and write some text into the file
    fptr = fopen(filename, fmode);
    if (fptr == NULL) { 
        printf("Cannot open filename \n"); 
        exit(0); 
    } 

    // Test by writing text into the file stream using fprintf()
    fprintf(fptr, "# Runfile: %s Date: %s Time : %s \n", __FILE__, __DATE__, __TIME__ );

    int i; double value, result;
    value = 0.5; 
    for(i = 0; i < 10; i++) {
       result = value/5.5;
       fprintf(fptr, "%d \t %f \t %f \n", i, value, result);
       value = value * 2.5;
    }
    fclose(fptr);

return(0);
}

在c中为日期和时间添加文件名

5 个答案: