xref: /illumos-gate/usr/src/lib/libc/port/stdio/fdopen.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 /*
31  * Unix routine to do an "fopen" on file descriptor
32  * The mode has to be repeated because you can't query its
33  * status
34  */
35 
36 #define	_LARGEFILE64_SOURCE 1
37 
38 #pragma weak _fdopen = fdopen
39 
40 #include "lint.h"
41 #include <mtlib.h>
42 #include "file64.h"
43 #include <sys/types.h>
44 #include <unistd.h>
45 #include <stdio.h>
46 #include <limits.h>
47 #include <thread.h>
48 #include <synch.h>
49 #include "stdiom.h"
50 #include <errno.h>
51 #include <fcntl.h>
52 
53 FILE *
54 fdopen(int fd, const char *type) /* associate file desc. with stream */
55 {
56 	/* iop doesn't need locking since this function is creating it */
57 	FILE *iop;
58 	char plus;
59 	unsigned char flag;
60 
61 	/* Sets EBADF for bad fds */
62 	if (fcntl(fd, F_GETFD) == -1)
63 		return (NULL);
64 
65 	if ((iop = _findiop()) == 0) {
66 		errno = ENOMEM;
67 		return (NULL);
68 	}
69 
70 	switch (type[0]) {
71 	default:
72 		iop->_flag = 0; /* release iop */
73 		errno = EINVAL;
74 		return (NULL);
75 	case 'r':
76 		flag = _IOREAD;
77 		break;
78 	case 'a':
79 		(void) lseek64(fd, (off64_t)0, SEEK_END);
80 		/*FALLTHROUGH*/
81 	case 'w':
82 		flag = _IOWRT;
83 		break;
84 	}
85 	if ((plus = type[1]) == 'b')	/* Unix ignores 'b' ANSI std */
86 		plus = type[2];
87 	if (plus == '+')
88 		flag = _IORW;
89 	iop->_flag = flag;
90 
91 #ifdef	_LP64
92 	iop->_file = fd;
93 #else
94 	if (fd <= _FILE_FD_MAX) {
95 		SET_FILE(iop, fd);
96 	} else if (_file_set(iop, fd, type) != 0) {
97 		/* errno set by _file_set () */
98 		iop->_flag = 0;		/* release iop */
99 		return (NULL);
100 	}
101 #endif	/*	_LP64	*/
102 
103 	return (iop);
104 }
105