src/lib/libc/stdio/freadptr.c

45 lines
1.3 KiB
C

/* $OpenBSD: freadptr.c,v 1.1 2024/08/12 20:56:55 guenther Exp $ */
/*
* Copyright (c) 2024 Philip Guenther <guenther@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdlib.h>
#include <stdio_ext.h>
#include "local.h"
const char *
__freadptr(FILE *fp, size_t *sizep)
{
if ((fp->_flags & __SRD) && fp->_r > 0) {
*sizep = fp->_r;
return fp->_p;
}
return NULL;
}
void
__freadptrinc(FILE *fp, size_t inc)
{
if (fp->_flags & __SRD) {
fp->_r -= inc;
fp->_p += inc;
if (fp->_r == 0 && HASUB(fp)) {
/* consumed the pushback buffer; switch back */
FREEUB(fp);
if ((fp->_r = fp->_ur) != 0)
fp->_p = fp->_up;
}
}
}