1 /*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)flags.c 8.1 (Berkeley) 6/4/93
33 * $FreeBSD: src/lib/libc/stdio/flags.c,v 1.10 2007/01/09 00:28:06 imp Exp $
34 */
35
36 #include <sys/types.h>
37 #include <stdio.h>
38 #include <errno.h>
39 #include <fcntl.h>
40
41 #include "local.h"
42
43 /*
44 * Return the (stdio) flags for a given mode. Store the flags
45 * to be passed to an _open() syscall through *optr.
46 * Return 0 on error.
47 */
48 int
__sflags(const char * mode,int * optr)49 __sflags(const char *mode, int *optr)
50 {
51 int ret, m, o;
52
53 /*
54 * Base mode
55 */
56 switch (*mode) {
57 case 'r':
58 /*
59 * Reading
60 */
61 ret = __SRD;
62 m = O_RDONLY;
63 o = 0;
64 break;
65 case 'w':
66 /*
67 * Writing
68 */
69 ret = __SWR;
70 m = O_WRONLY;
71 o = O_CREAT | O_TRUNC;
72 break;
73 case 'a':
74 /*
75 * Append
76 */
77 ret = __SWR;
78 m = O_WRONLY;
79 o = O_CREAT | O_APPEND;
80 break;
81 default:
82 /*
83 * Illegal primary mode, fail.
84 */
85 errno = EINVAL;
86 return (0);
87 }
88
89 /*
90 * Parse modifiers
91 */
92 for (++mode; *mode; ++mode) {
93 switch(*mode) {
94 case '+':
95 /*
96 * R+W
97 */
98 ret = __SRW;
99 m = O_RDWR;
100 break;
101 case 'b':
102 /*
103 * Binary (inherent, no special treatment)
104 */
105 break;
106 case 'x':
107 /*
108 * Exclusive. Only make sense if opening for
109 * r+w, w, or a, but let open() deal with
110 * any issues (make behavior the same as glibc).
111 */
112 o |= O_EXCL;
113 break;
114 case 'e':
115 o |= O_CLOEXEC;
116 break;
117 default:
118 /* ignore unrecognized flag */
119 break;
120 }
121 }
122 *optr = m | o;
123
124 return (ret);
125 }
126