xref: /illumos-gate/usr/src/lib/libc/port/stdio/fdopen.c (revision 92a0208178405fef708b0283ffcaa02fbc3468ff)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * Unix routine to do an "fopen" on file descriptor
34  * The mode has to be repeated because you can't query its
35  * status
36  */
37 
38 #define	_LARGEFILE64_SOURCE 1
39 
40 #pragma weak _fdopen = fdopen
41 
42 #include "lint.h"
43 #include <mtlib.h>
44 #include "file64.h"
45 #include <sys/types.h>
46 #include <unistd.h>
47 #include <stdio.h>
48 #include <limits.h>
49 #include <thread.h>
50 #include <synch.h>
51 #include "stdiom.h"
52 #include <errno.h>
53 #include <fcntl.h>
54 
55 FILE *
56 fdopen(int fd, const char *type) /* associate file desc. with stream */
57 {
58 	/* iop doesn't need locking since this function is creating it */
59 	FILE *iop;
60 	char plus;
61 	unsigned char flag;
62 
63 	/* Sets EBADF for bad fds */
64 	if (fcntl(fd, F_GETFD) == -1)
65 		return (NULL);
66 
67 	if ((iop = _findiop()) == 0) {
68 		errno = ENOMEM;
69 		return (NULL);
70 	}
71 
72 	switch (type[0]) {
73 	default:
74 		iop->_flag = 0; /* release iop */
75 		errno = EINVAL;
76 		return (NULL);
77 	case 'r':
78 		flag = _IOREAD;
79 		break;
80 	case 'a':
81 		(void) lseek64(fd, (off64_t)0, SEEK_END);
82 		/*FALLTHROUGH*/
83 	case 'w':
84 		flag = _IOWRT;
85 		break;
86 	}
87 	if ((plus = type[1]) == 'b')	/* Unix ignores 'b' ANSI std */
88 		plus = type[2];
89 	if (plus == '+')
90 		flag = _IORW;
91 	iop->_flag = flag;
92 
93 #ifdef	_LP64
94 	iop->_file = fd;
95 #else
96 	if (fd <= _FILE_FD_MAX) {
97 		SET_FILE(iop, fd);
98 	} else if (_file_set(iop, fd, type) != 0) {
99 		/* errno set by _file_set () */
100 		iop->_flag = 0;		/* release iop */
101 		return (NULL);
102 	}
103 #endif	/*	_LP64	*/
104 
105 	return (iop);
106 }
107