在c中为日期和时间添加文件名

Question

我正在寻找一种方法将当前日期和时间添加到我现在打开的日志文件中使用:

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

如何制作它

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

很多(在c)

Answer 1

strftime 可用于格式化日期的时间:

#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");

根据strftime手册,您可以根据需要更改日期时间格式.

您可以将时间戳用作"紧凑格式",time仅显示结果.

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;
}

输出是

/var/log/SA_TEST_Wed_Jul_30_12:17:19_2014