1 /*
2 * Copyright (c) 1990 Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * and/or other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17 /* No user fns here. Pesch 15apr92 */
18
19 #include "stdio_private.h"
20
21 /*
22 * In POSIX_IO mode, this is called __posix_sflags and __stdio_sflags
23 * is a static inline on top of this. Otherwise, this is called
24 * __stdio_sflags.
25 *
26 * Return the (stdio) flags for a given mode. When POSIX_IO is
27 * available, also store the flags to be passed to an open() syscall
28 * through *optr.
29 *
30 * Return 0 on error.
31 */
32
33 #ifdef POSIX_IO
34 int
__posix_sflags(const char * mode,int * optr)35 __posix_sflags (const char *mode, int *optr)
36 #else
37 int
38 __stdio_sflags (const char *mode)
39 #endif
40 {
41 int ret;
42 #ifdef POSIX_IO
43 int m, o;
44 #endif
45
46 switch (mode[0])
47 {
48 case 'r': /* open for reading */
49 ret = __SRD;
50 #ifdef POSIX_IO
51 m = O_RDONLY;
52 o = 0;
53 #endif
54 break;
55
56 case 'w': /* open for writing */
57 ret = __SWR;
58 #ifdef POSIX_IO
59 m = O_WRONLY;
60 o = O_CREAT | O_TRUNC;
61 #endif
62 break;
63
64 case 'a': /* open for appending */
65 ret = __SWR;
66 #ifdef POSIX_IO
67 m = O_WRONLY;
68 o = O_CREAT | O_APPEND;
69 #endif
70 break;
71 default: /* illegal mode */
72 errno = EINVAL;
73 return (0);
74 }
75 while (*++mode)
76 {
77 switch (*mode)
78 {
79 case '+':
80 ret |= (__SRD | __SWR);
81 #ifdef POSIX_IO
82 m = (m & ~O_ACCMODE) | O_RDWR;
83 #endif
84 break;
85 default:
86 break;
87 }
88 }
89 #ifdef POSIX_IO
90 *optr = m | o;
91 #endif
92 return ret;
93 }
94
