1/* Copyright (C) 1993-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>.
17
18 As a special exception, if you link the code in this file with
19 files compiled with a GNU compiler to produce an executable,
20 that does not cause the resulting executable to be covered by
21 the GNU Lesser General Public License. This exception does not
22 however invalidate any other reasons why the executable file
23 might be covered by the GNU Lesser General Public License.
24 This exception applies to code released by its copyright holders
25 in files containing the exception. */
26
27/*
28 Copyright (C) 1990 The Regents of the University of California.
29 All rights reserved.
30
31 Redistribution and use in source and binary forms, with or without
32 modification, are permitted provided that the following conditions
33 are met:
34
35 1. Redistributions of source code must retain the above copyright
36 notice, this list of conditions and the following disclaimer.
37 2. Redistributions in binary form must reproduce the above copyright
38 notice, this list of conditions and the following disclaimer in the
39 documentation and/or other materials provided with the distribution.
40 4. Neither the name of the University nor the names of its contributors
41 may be used to endorse or promote products derived from this software
42 without specific prior written permission.
43
44 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
45 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47 ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
48 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54 SUCH DAMAGE.*/
55
56/* Modified for GNU iostream by Per Bothner 1991, 1992. */
57
58#include "libioP.h"
59#include <device-nrs.h>
60#include <sys/stat.h>
61#include <stdlib.h>
62#include <unistd.h>
63
64/* Return the result of isatty, without changing errno. */
65static int
66local_isatty (int fd)
67{
68 int save_errno = errno;
69 int res = __isatty (fd);
70 __set_errno (save_errno);
71 return res;
72}
73
74/* Allocate a file buffer, or switch to unbuffered I/O. Streams for
75 TTY devices default to line buffered. */
76int
77_IO_file_doallocate (FILE *fp)
78{
79 size_t size;
80 char *p;
81 struct stat64 st;
82
83 size = BUFSIZ;
84 if (fp->_fileno >= 0 && __builtin_expect (_IO_SYSSTAT (fp, &st), 0) >= 0)
85 {
86 if (S_ISCHR (st.st_mode))
87 {
88 /* Possibly a tty. */
89 if (
90#ifdef DEV_TTY_P
91 DEV_TTY_P (&st) ||
92#endif
93 local_isatty (fp->_fileno))
94 fp->_flags |= _IO_LINE_BUF;
95 }
96#if defined _STATBUF_ST_BLKSIZE
97 if (st.st_blksize > 0 && st.st_blksize < BUFSIZ)
98 size = st.st_blksize;
99#endif
100 }
101 p = malloc (size);
102 if (__glibc_unlikely (p == NULL))
103 return EOF;
104 _IO_setb (fp, p, p + size, 1);
105 return 1;
106}
107libc_hidden_def (_IO_file_doallocate)
108