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
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
/* Open a stream to a file.
Copyright (C) 2007-2023 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
/* If the user's config.h happens to include <stdio.h>, let it include only
the system's <stdio.h> here, so that orig_fopen doesn't recurse to
rpl_fopen. */
#define _GL_ALREADY_INCLUDING_STDIO_H
#include <config.h>
/* Get the original definition of fopen. It might be defined as a macro. */
#include <stdio.h>
#undef _GL_ALREADY_INCLUDING_STDIO_H
static FILE *
orig_fopen (const char *filename, const char *mode)
{
return fopen (filename, mode);
}
/* Specification. */
/* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates
this include because of the preliminary #include <stdio.h> above. */
#include "stdio.h"
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
FILE *
rpl_fopen (const char *filename, const char *mode)
{
int open_direction;
int open_flags;
#if GNULIB_FOPEN_GNU
bool open_flags_gnu;
# define BUF_SIZE 80
char fdopen_mode_buf[BUF_SIZE + 1];
#endif
#if defined _WIN32 && ! defined __CYGWIN__
if (strcmp (filename, "/dev/null") == 0)
filename = "NUL";
#endif
/* Parse the mode. */
open_direction = 0;
open_flags = 0;
#if GNULIB_FOPEN_GNU
open_flags_gnu = false;
#endif
{
const char *p = mode;
#if GNULIB_FOPEN_GNU
char *q = fdopen_mode_buf;
#endif
for (; *p != '\0'; p++)
{
switch (*p)
{
case 'r':
open_direction = O_RDONLY;
#if GNULIB_FOPEN_GNU
if (q < fdopen_mode_buf + BUF_SIZE)
*q++ = *p;
#endif
continue;
case 'w':
open_direction = O_WRONLY;
open_flags |= O_CREAT | O_TRUNC;
#if GNULIB_FOPEN_GNU
if (q < fdopen_mode_buf + BUF_SIZE)
*q++ = *p;
#endif
continue;
case 'a':
open_direction = O_WRONLY;
open_flags |= O_CREAT | O_APPEND;
#if GNULIB_FOPEN_GNU
if (q < fdopen_mode_buf + BUF_SIZE)
*q++ = *p;
#endif
continue;
case 'b':
/* While it is non-standard, O_BINARY is guaranteed by
gnulib <fcntl.h>. We can also assume that orig_fopen
supports the 'b' flag. */
open_flags |= O_BINARY;
#if GNULIB_FOPEN_GNU
if (q < fdopen_mode_buf + BUF_SIZE)
*q++ = *p;
#endif
continue;
case '+':
open_direction = O_RDWR;
#if GNULIB_FOPEN_GNU
if (q < fdopen_mode_buf + BUF_SIZE)
*q++ = *p;
#endif
continue;
#if GNULIB_FOPEN_GNU
case 'x':
open_flags |= O_EXCL;
open_flags_gnu = true;
continue;
case 'e':
open_flags |= O_CLOEXEC;
open_flags_gnu = true;
continue;
#endif
default:
break;
}
#if GNULIB_FOPEN_GNU
/* The rest of the mode string can be a platform-dependent extension.
Copy it unmodified. */
{
size_t len = strlen (p);
if (len > fdopen_mode_buf + BUF_SIZE - q)
len = fdopen_mode_buf + BUF_SIZE - q;
memcpy (q, p, len);
q += len;
}
#endif
break;
}
#if GNULIB_FOPEN_GNU
*q = '\0';
#endif
}
#if FOPEN_TRAILING_SLASH_BUG
/* Fail if the mode requires write access and the filename ends in a slash,
as POSIX says such a filename must name a directory
<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
"A pathname that contains at least one non-<slash> character and that
ends with one or more trailing <slash> characters shall not be resolved
successfully unless the last pathname component before the trailing
<slash> characters names an existing directory"
If the named file already exists as a directory, then if a mode that
requires write access is specified, fopen() must fail because POSIX
<https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html>
says that it fails with errno = EISDIR in this case.
If the named file does not exist or does not name a directory, then
fopen() must fail since the file does not contain a '.' directory. */
{
size_t len = strlen (filename);
if (len > 0 && filename[len - 1] == '/')
{
int fd;
struct stat statbuf;
FILE *fp;
if (open_direction != O_RDONLY)
{
errno = EISDIR;
return NULL;
}
fd = open (filename, open_direction | open_flags,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
if (fd < 0)
return NULL;
if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
{
close (fd);
errno = ENOTDIR;
return NULL;
}
# if GNULIB_FOPEN_GNU
fp = fdopen (fd, fdopen_mode_buf);
# else
fp = fdopen (fd, mode);
# endif
if (fp == NULL)
{
int saved_errno = errno;
close (fd);
errno = saved_errno;
}
return fp;
}
}
#endif
#if GNULIB_FOPEN_GNU
if (open_flags_gnu)
{
int fd;
FILE *fp;
fd = open (filename, open_direction | open_flags,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
if (fd < 0)
return NULL;
fp = fdopen (fd, fdopen_mode_buf);
if (fp == NULL)
{
int saved_errno = errno;
close (fd);
errno = saved_errno;
}
return fp;
}
#endif
return orig_fopen (filename, mode);
}
|
