multiplication table in C

gistfile1.h

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

/* a simple multiplication table */
int main()
{
  char *cp;
  char buffer[256];

  printf("Enter a number:\n");
  cp = fgets(buffer, 256, stdin);

  int num = 0;
  if (cp != NULL)
    {
      num = atoi(cp);
      printf("Table size: %d\n", num);
    }
  
  int row, col;
  for (row = 1; row < num+1; row++)
    {
      for (col = 1; col < num+1; col++)
        {
          printf("%3d ", row*col);
        }
      printf("\n");
    }

  return 0;
}

Please some explanations

It should really be named something like table.c. It's just a simple script (I was probably working on my C at the time and just wanted to test-compile something). Here's what it does:

> clang gist.c -o gist
> ./gist 
Enter a number:
5
Table size: 5
  1   2   3   4   5 
  2   4   6   8  10 
  3   6   9  12  15 
  4   8  12  16  20 
  5  10  15  20  25