A simple C function to print time

time.c

#include <string.h>
#include <stdio.h>
#include <time.h>
#include <sys/time.h>

#define LENGTH 256

void print_time(char *buf)
{
    time_t t;
    struct timeval tv;
    gettimeofday(&tv, NULL); 
    time(&t);
    sprintf(buf, 256 ,"%f", tv.tv_sec + (tv.tv_usec * 0.000001)); 
    return buf;
}

int main() {
    char *buf;
    buf = (char*)malloc(LENGTH);
    if(buf==NULL) {
      fprintf(stderr, "Unable to alocate %d bytes", LENGTH)
      return -1;
    }
    memset(buf,'\0', LENGTH);
    print_time(buf);
    fprintf(stdout, "time=%s", buf);
    return 0;
}