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

static void usage (void) __attribute__ ((unused));

int
main (int argc, char *argv[])
{
  if (argc < 2) 
    {
      int c;
      while ((c = getchar()) != EOF) 
        {
          putchar(c);
        }
      return EXIT_SUCCESS;
    }

  FILE *fp = fopen(argv[1], "r");
  if (fp == NULL)
    {
      return EXIT_FAILURE;
    }
   
  int c;
  while ((c = fgetc(fp)) != EOF)
    {
      putchar(c);
    }

  fclose(fp);

  return EXIT_SUCCESS;
}

static void
usage (void)
{
  printf ("cat, print the contents of a file\n");
  printf ("usage: cat FILE\n");
}