HardenedBSD/lib/libc/stdio/ftell.c
Warner Losh dc36d6f9bb lib: Remove ancient SCCS tags.
Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by:		Netflix
2023-11-26 22:23:28 -07:00

138 lines
3.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "namespace.h"
#include <sys/types.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include "un-namespace.h"
#include "local.h"
#include "libc_private.h"
/*
* standard ftell function.
*/
long
ftell(FILE *fp)
{
off_t rv;
rv = ftello(fp);
if (rv > LONG_MAX) {
errno = EOVERFLOW;
return (-1);
}
return (rv);
}
/*
* ftello: return current offset.
*/
off_t
ftello(FILE *fp)
{
fpos_t rv;
int ret;
FLOCKFILE(fp);
ret = _ftello(fp, &rv);
FUNLOCKFILE(fp);
if (ret)
return (-1);
if (rv < 0) { /* Unspecified value because of ungetc() at 0 */
errno = ESPIPE;
return (-1);
}
return (rv);
}
int
_ftello(FILE *fp, fpos_t *offset)
{
fpos_t pos;
size_t n;
if (fp->_seek == NULL) {
errno = ESPIPE; /* historic practice */
return (1);
}
/*
* Find offset of underlying I/O object, then
* adjust for buffered bytes.
*/
if (!(fp->_flags & __SRD) && (fp->_flags & __SWR) &&
fp->_p != NULL && fp->_p - fp->_bf._base > 0 &&
((fp->_flags & __SAPP) || (fp->_flags2 & __S2OAP))) {
pos = _sseek(fp, (fpos_t)0, SEEK_END);
if (pos == -1)
return (1);
} else if (fp->_flags & __SOFF)
pos = fp->_offset;
else {
pos = _sseek(fp, (fpos_t)0, SEEK_CUR);
if (pos == -1)
return (1);
}
if (fp->_flags & __SRD) {
/*
* Reading. Any unread characters (including
* those from ungetc) cause the position to be
* smaller than that in the underlying object.
*/
if ((pos -= (HASUB(fp) ? fp->_ur : fp->_r)) < 0) {
fp->_flags |= __SERR;
errno = EIO;
return (1);
}
if (HASUB(fp))
pos -= fp->_r; /* Can be negative at this point. */
} else if ((fp->_flags & __SWR) && fp->_p != NULL &&
(n = fp->_p - fp->_bf._base) > 0) {
/*
* Writing. Any buffered characters cause the
* position to be greater than that in the
* underlying object.
*/
if (pos > OFF_MAX - n) {
errno = EOVERFLOW;
return (1);
}
pos += n;
}
*offset = pos;
return (0);
}