Sync usage with man page.
[netbsd-mini2440.git] / lib / libc / stdio / fopen.c
blob778bf2e4424b3869a035d27124c8b9246bc73489
1 /* $NetBSD: fopen.c,v 1.12 2003/08/07 16:43:24 agc Exp $ */
3 /*-
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)fopen.c 8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: fopen.c,v 1.12 2003/08/07 16:43:24 agc Exp $");
41 #endif
42 #endif /* LIBC_SCCS and not lint */
44 #include <sys/types.h>
45 #include <sys/stat.h>
46 #include <assert.h>
47 #include <fcntl.h>
48 #include <unistd.h>
49 #include <stdio.h>
50 #include <errno.h>
51 #include <limits.h>
52 #include "reentrant.h"
53 #include "local.h"
55 FILE *
56 fopen(file, mode)
57 const char *file;
58 const char *mode;
60 FILE *fp;
61 int f;
62 int flags, oflags;
64 _DIAGASSERT(file != NULL);
65 if ((flags = __sflags(mode, &oflags)) == 0)
66 return (NULL);
67 if ((fp = __sfp()) == NULL)
68 return (NULL);
69 if ((f = open(file, oflags, DEFFILEMODE)) < 0)
70 goto release;
71 if (oflags & O_NONBLOCK) {
72 struct stat st;
73 if (fstat(f, &st) == -1) {
74 int sverrno = errno;
75 (void)close(f);
76 errno = sverrno;
77 goto release;
79 if (!S_ISREG(st.st_mode)) {
80 (void)close(f);
81 errno = EFTYPE;
82 goto release;
86 * File descriptors are a full int, but _file is only a short.
87 * If we get a valid file descriptor that is greater or equal to
88 * USHRT_MAX, then the fd will get sign-extended into an
89 * invalid file descriptor. Handle this case by failing the
90 * open. (We treat the short as unsigned, and special-case -1).
92 if (f >= USHRT_MAX) {
93 errno = EMFILE;
94 goto release;
97 fp->_file = f;
98 fp->_flags = flags;
99 fp->_cookie = fp;
100 fp->_read = __sread;
101 fp->_write = __swrite;
102 fp->_seek = __sseek;
103 fp->_close = __sclose;
106 * When opening in append mode, even though we use O_APPEND,
107 * we need to seek to the end so that ftell() gets the right
108 * answer. If the user then alters the seek pointer, or
109 * the file extends, this will fail, but there is not much
110 * we can do about this. (We could set __SAPP and check in
111 * fseek and ftell.)
113 if (oflags & O_APPEND)
114 (void) __sseek((void *)fp, (fpos_t)0, SEEK_END);
115 return (fp);
116 release:
117 fp->_flags = 0; /* release */
118 return (NULL);