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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
/*
* Copyright 2020 Robert Mustacchi
*/
#define _LARGEFILE64_SOURCE 1
#include "lint.h"
#include "file64.h"
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "stdiom.h"
/*
* If buffer space has been pre-allocated use it otherwise malloc space.
* PUSHBACK causes the base pointer to be bumped forward. At least 4 bytes
* of pushback are required to meet international specifications.
* Extra space at the end of the buffer allows for synchronization problems.
* If malloc() fails stdio bails out; assumption being the system is in trouble.
* Associate a buffer with stream; return NULL on error.
*/
Uchar *
_findbuf(FILE *iop)
{
int fd = _get_fd(iop);
Uchar *buf;
int size = BUFSIZ;
Uchar *endbuf;
int tty = -1;
if (iop->_flag & _IONBF) { /* need a small buffer, at least */
trysmall:
size = _SMBFSZ - PUSHBACK;
if (fd >= 0 && fd < _NFILE) {
buf = _smbuf[fd];
} else if ((buf = (Uchar *)malloc(_SMBFSZ * sizeof (Uchar))) !=
NULL) {
iop->_flag |= _IOMYBUF;
}
} else if (fd >= 0 && fd < 2 && (tty = isatty(fd))) {
/* Use special buffers for standard in and standard out */
buf = (fd == 0) ? _sibuf : _sobuf;
} else {
/*
* The operating system can tell us the right size for a buffer;
* avoid 0-size buffers as returned for some special files
* (doors). Use the default buffer size for memory streams.
*/
struct stat64 stbuf;
if (fd != -1 && fstat64(fd, &stbuf) == 0 && stbuf.st_blksize >
0) {
size = stbuf.st_blksize;
}
if ((buf = (Uchar *)malloc(sizeof (Uchar)*(size+_SMBFSZ))) !=
NULL) {
iop->_flag |= _IOMYBUF;
} else {
goto trysmall;
}
}
if (buf == NULL)
return (NULL); /* malloc() failed */
iop->_base = buf + PUSHBACK; /* bytes for pushback */
iop->_ptr = buf + PUSHBACK;
endbuf = iop->_base + size;
_setbufend(iop, endbuf);
if (!(iop->_flag & _IONBF) && ((tty != -1) ? tty : isatty(fd)))
iop->_flag |= _IOLBF;
return (endbuf);
}
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