1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/* $NetBSD: open.c,v 1.10 1996/01/13 22:25:41 leo Exp $ */
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)open.c 8.1 (Berkeley) 6/11/93
*
*
* Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Author: Alessandro Forin
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include "stand.h"
struct open_file files[SOPEN_MAX];
/*
* File primitives proper
*/
int
open(fname, mode)
const char *fname;
int mode;
{
register struct open_file *f;
register int fd, i, error;
char *file;
/* find a free file descriptor */
for (fd = 0, f = files; fd < SOPEN_MAX; fd++, f++)
if (f->f_flags == 0)
goto fnd;
errno = EMFILE;
return (-1);
fnd:
/*
* Try to open the device.
* Convert open mode (0,1,2) to F_READ, F_WRITE.
*/
f->f_flags = mode + 1;
f->f_dev = (struct devsw *)0;
f->f_ops = (struct fs_ops *)0;
file = (char *)0;
error = devopen(f, fname, &file);
if (error ||
(((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0))
goto err;
/* see if we opened a raw device; otherwise, 'file' is the file name. */
if (file == (char *)0 || *file == '\0') {
f->f_flags |= F_RAW;
return (0);
}
/* pass file name to the different filesystem open routines */
for (i = 0; i < nfsys; i++) {
/* convert mode (0,1,2) to FREAD, FWRITE. */
error = (file_system[i].open)(file, f);
if (error == 0) {
f->f_ops = &file_system[i];
return (fd);
}
}
if (!error)
error = ENOENT;
err:
f->f_flags = 0;
errno = error;
return (-1);
}
|
