C Error Log Writing

场景记录

Catch mistakes and output > testlog

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


int write_log (FILE* pFile, const char *format, ...) {

    va_list arg;
    int done;

    va_start (arg, format);

    time_t time_log = time(NULL);
    struct tm* tm_log = localtime(&time_log);
    fprintf(pFile, "%04d-%02d-%02d %02d:%02d:%02d ", tm_log->tm_year + 1900, tm_log->tm_mon + 1, tm_log->tm_mday, tm_log->tm_hour, tm_log->tm_min, tm_log->tm_sec);

    done = vfprintf (pFile, format, arg);
    va_end (arg);

    fflush(pFile);
    return done;
}

int main() {

    FILE* pFile = fopen("testlog", "a");  // append or write
    write_log(pFile, "%s %d %f\n", "found err", 10, 55.55);
    fclose(pFile);

    return 0;
}

output:

2021-03-09 17:28:25 is running 10 55.550000