Thread: Random Sequence + Time ?

Hi everyone,
I got a piece of C code to "evolve"(Text wants me to create another file with the same structure but it's another thing)-in reality it's the past "went-bad" exam.-
I can't figure out how "srand" works with time in this code?
I repeat that I got a book where I study,but I already tried once this exam and everytime new functions appears.
I go up looking in the book and with ctrl+f = srand appears only 1 time near to int rand(void).
This is the code:

Code:

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

#define ARRLEN 30
#define MAXREC 300
#define STRINGLEN 20

typedef
  struct
  {
    int numbers[ARRLEN];
    char name1[STRINGLEN+1];
    char name2[STRINGLEN+1];
  }
  t_datum;


int main()
{
  FILE *f;
  t_datum x;
  int i,k,n,temp;
  srand(time(0));                            //   <-- WHAT'S THIS?
  n = MAXREC + rand() % MAXREC;
  if ((f = fopen("archive","wb")))
  {    
    for (k = 0; k < n; k++)
    {
      for (i=0; i<ARRLEN; i++)
        x.numbers[i]=rand()%10000;
      for (i=0;i < STRINGLEN; i++)
      {
        temp=rand()%8;
        if (temp==0)  
          x.name1[i]= 32;
        else  
          x.name1[i]= 65 + rand()%26;
      }
      x.name1[STRINGLEN]='\0';
      for (i=0;i < STRINGLEN; i++)
      {    
        temp=rand()%8;
        if (temp==0)  
          x.name2[i]= 32;
        else  
          x.name2[i]= 97 + rand()%26;
      }      
      x.name2[STRINGLEN]='\0';
      fwrite(&x,sizeof(t_datum),1,f);
    }
    fclose(f);
  }
  else
    printf("Error opening the file.\n");
  return 0;
}

Ps. I have tomorrow the next C test and maybe I'll be willing to go if i can solve at least a part of this test...if you want the whole text requests for what to do tell me and I'll write the full text.