L C K F I O  -- File I/O module


Z O P E N I  --  Open an existing file for input. Return 1 if successful

		  zopeni(n,name)
		  int n = file number to use
		  char *name = name of file to open

Z O P E N O  --   Open a new file for output.  Return 1 if successful

		  zopeno(n,name)
		  int n = file number to use
		  char *name = name of file to open

Z C L O S E  --   Close the given file. Return 1 if successful

		  zclose(n)
		  int n = number of file to close

Z C H I N  --	  Get a character from the input file.
		  Returns -1 if EOF, 0 otherwise.

		  zchin(n,c)
		  int n = number of file to read
		  char *c = character read

Z S O U T  --	  Write a string to the given file, buffered.
		  Returns -1 if ERROR, 0 otherwise

		  zsout(n,s)
		  int n = number of file to write to
		  char *s = character string to write

Z S O U T L  --   Write string to file, with line terminator, buffered
		  Returns -1 if ERROR, 0 otherwise

		  zsoutl(n,s)
		  int n = number of file to write to
		  char *s = character string to write

Z S O U T X  --   Write x characters to file, unbuffered.
		  Returns -1 if ERROR, 0 otherwise

		  zsoutx(n,s,x)
		  int n = number of file to write to
		  int x = number of character to write
		  char *s = character string to write

Z C H O U T  --   Add a character to the given file.
		  Returns -1 if ERROR, 0 otherwise

		  zchout(n,c)
		  int n = number of file to write to
		  char c = character to write

C H K F N  --	  Internal function to verify file number is ok
		  Returns:  -1 = File number n is out of range
			     0 = n is in range, but file is not open
			     1 = n in range and file is open

		  chkfn(n)
		  int n = file number to check

Z C H K I  --	  Check if input file exists and is readable
		  Returns:  >= 0 if the file can be read (returns the size).
			      -1 if file doesn't exist or can't be accessed,
			      -2 if file exists but is not readable .
			      -3 if file exists but protected against read.

		  long zchki(name)
		  char *name = name of file to check

Z C H K O  --	  Check if output file can be created . Returns -1 if write
		  permission for the file would be denied, 0 otherwise.

		  zchko(name)
		  char *name = name of file to check

Z D E L E T  --   Delete the named file.

		  zdelet(name)
		  char *name = name of file to delete

Z R T O L  --	  Convert remote filename into local form
		  For DOS, this means changing lowercase letters to uppercase.

		  zrtol(name,name2)
		  char *name = file name to be converted
		  char *name2 = converted file name

Z L T O R  --	  Convert filename from local format to common form.
		  Strip pathnames, directory names and uppercase.

		  zltor(name,name2)
		  char *name = file name to be converted
		  char *name2 = converted file name

Z N E X T  --	  Get name of next file from list created by zxpand().
		  Returns >0 if there's another file or 0 if no more files.

		  znext(fn)
		  char *fn = filename

Z N E W N  --	  Make a new name for the given file

		  znewn(fn,s)
		  char *fn = filename to be converted
		  char **s = pointer to converted file name

Z X P A N D  --   Expand a wildcard string into an array of strings
		  Returns the number of files that match fn1,
		  with data structures set up so that first file (if any)
		  will be returned by the next znext() call.

		  zxpand(fn)
		  char *fn = filename to be expanded

Z N E X T  --	  Get name of next file from list created by zxpand().
		  Returns >0 if there's another file or 0 if no more files.

		  znext(fn)
		  char *fn = filename

Z F C D A T  --   Return file creation date/time

		  zfcdat(fname,str)
		  char *fname = filename
		  char *str = string with date and time

Z F R E E --	  Return total number of free bytes on drive specified

		  long zfree(drive)
		  char *drive = drive name to check

Z F P D A T --	  Stamp a given file name with the given date

		  zfpdat(fname,dattim)
		  char *fname = name of file to stamp
		  cahr *dattim = date and time to stamp