/**
 * cat file1 file2 ... filen
 *   Print out the contents of the given files.  Based on code
 *   from sections 7.5 and 7.6 of K&R.
 */

// +---------+--------------------------------------------------------
// | Headers |
// +---------+

#include <stdio.h>


// +---------+--------------------------------------------------------
// | Helpers |
// +---------+

/**
 * filecopy(ifp, ofp)
 *   Copy from ifp to ofp.
 */
void
filecopy (FILE *ifp, FILE *ofp)
{
  int c;
  while ((c = getc (ifp)) != EOF)
    putc (c, ofp);
} // filecopy


// +------+-----------------------------------------------------------
// | Main |
// +------+

int
main (int argc, char *argv[])
{
  FILE *fp;		// The current input file.
  char *prog = argv[0]; // The name of the program, used for output

  // If no file names are given, copy from standard input to standard output.
  if (argc == 1)
    filecopy (stdin, stdout);

  // Normal behavior: Print contents of all files to stdout
  else
    {
      // As long as files remain
      while (--argc > 0)
        {
          // Grab the current file
          fp = fopen (*++argv, "r");
          // Check for failure
          if (fp == NULL)
            {
              fprintf (stderr, "%s: can't open file %s\n", prog, *argv);
              return 1;
            }
          // Yay!  The open succeeded.  Print the file and close it.
          filecopy (fp, stdout);
          fclose (fp);
        } // while
    } // normal behavior

  // Did something go wrong?  If so, indicate that an error occured.
  if (ferror (stdout))
    {
      fprintf (stderr, "%s: error writing to stdout\n", prog);
      return 2;
    } // if something went wrong

  // Okay, nothing went wrong
  return 0;
} // main