#include <stdio.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <unistd.h>
#include <linux/types.h>
#include <linux/dirent.h>
#include <linux/unistd.h>

long processFile ();
long processDirectory ();

main (argc, argv)
     int argc;
     char* argv[];
{
  long count;
  count = processFile (argv[1]);
  printf ("Total number of non-directory files is %ld\n", count);
  return (0);
}

long processFile (name)
     char* name;
{
  struct stat statBuf; /* To hold the return data from stat () */
  mode_t mode;
  int result;
  result = stat (name, &statBuf); /* Stat the specified file */
  if (result == -1) return (0); /* Error */
  mode = statBuf.st_mode; /* Look at the file's mode */
  if (S_ISDIR (mode)) /* Directory */
    return (processDirectory (name));
  else
    return (1); /* A nondirectory file was processed */
}

long processDirectory (dirName)
     char* dirName;
{
  int fd, children, i, charsRead, childPid, status;
  long count, totalCount;
  char fileName[100];
  struct dirent dirEntry;
  fd = open (dirName, O_RDONLY); /* Open directory for reading */
  children = 0; /* Initialize child process count */
  while (1) /* Scan directory */
    {
      charsRead = getdents (fd, &dirEntry, sizeof (struct dirent));
      if (charsRead == 0) break; /* End of directory */
      if (strcmp (dirEntry.d_name, ".") != 0  &&
	  strcmp (dirEntry.d_name, "..") != 0)
	{
	  if (fork () == 0) /* Create a child to process dir. entry */
	    {
	      sprintf (fileName, "%s%s", dirName, dirEntry.d_name);
	      count = processFile (fileName);
	      exit (count);
	    }
	  else
	    ++children; /* Increment count of child processes */
	}
      lseek (fd, dirEntry.d_off, SEEK_SET); /* Jump to next dir. entry */
    }
  close (fd); /* Close directory */
  totalCount = 0; /* Initialize file count */
  for (i = 1; i <= children; i++) /* Wait for children to terminate */
    {
      childPid = wait (&status); /* Accept child's termination code */
      totalCount += (status >> 8); /* Update file count */
    }
  return (totalCount); /* Return number of files in directory */
}