OpenBSD-4.6/usr.bin/sup/src/ffilecopy.c

/*	$OpenBSD: ffilecopy.c,v 1.6 2001/05/04 22:16:15 millert Exp $	*/

/*
 * Copyright (c) 1991 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator   or   Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the rights
 * to redistribute these changes.
 */
/*  ffilecopy  --  very fast buffered file copy
 *
 *  Usage:  i = ffilecopy (here,there)
 *	int i;
 *	FILE *here, *there;
 *
 *  Ffilecopy is a very fast routine to copy the rest of a buffered
 *  input file to a buffered output file.  Here and there are open
 *  buffers for reading and writing (respectively); ffilecopy
 *  performs a file-copy faster than you should expect to do it
 *  yourself.  Ffilecopy returns 0 if everything was OK; EOF if
 *  there was any error.  Normally, the input file will be left in
 *  EOF state (feof(here) will return TRUE), and the output file will be
 *  flushed (i.e. all data on the file rather in the core buffer).
 *  It is not necessary to flush the output file before ffilecopy.
 *
 *  HISTORY
 * 20-Nov-79  Steven Shafer (sas) at Carnegie-Mellon University
 *	Created for VAX.
 *
 */

#include <stdio.h>
#include "supcdefs.h"
#include "supextern.h"

int
ffilecopy(here,there)
	FILE *here, *there;
{
	int i, herefile, therefile;

	herefile = fileno(here);
	therefile = fileno(there);

	if (fflush(there) == EOF)		/* flush pending output */
		return (EOF);

#ifdef _FSTDIO
	if ((here->_r) > 0) {			/* flush buffered input */
		i = write(therefile, here->_p, here->_r);
		if (i != here->_r)
			return (EOF);
		here->_p = here->_bf._base;
		here->_r = 0;
	}
#else
	if ((here->_cnt) > 0) {			/* flush buffered input */
		i = write(therefile, here->_ptr, here->_cnt);
		if (i != here->_cnt)
			return (EOF);
		here->_ptr = here->_base;
		here->_cnt = 0;
	}
#endif /* _FSTDIO */

	i = filecopy(herefile, therefile);	/* fast file copy */
	if (i < 0)
		return (EOF);

#ifdef _FSTDIO
	(here->_flags) |= __SEOF;		/* indicate EOF */
#else
	(here->_flag) |= _IOEOF;		/* indicate EOF */
#endif
	return (0);
}