Draws a rectangle divided in half

flag.c

/*
 * ./this width height topRGB bottomRGB
 * ./this 400 400 FFFF00 000000 | feh -
 */
#include <stdio.h>
#include <stdlib.h>

int
main(int argc, char **argv)
{
  if (argc != 5)
    return 1;
  int w      = atoi(argv[1]),
      h      = atoi(argv[2]),
      top    = strtol(argv[3], 0, 16),
      bottom = strtol(argv[4], 0, 16);
  printf("P3 %d %d 255 ", w, h);
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++)
      if ((i * w) - (j * h) > 0)
        printf("%d %d %d ", top >> 16, top >> 8 & 0xFF, top & 0xFF);
      else
        printf("%d %d %d ", bottom >> 16, bottom >> 8 & 0xFF, bottom & 0xFF);
  return 0;
}