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
|
/* Libiberty realpath. Like realpath, but more consistent behavior.
Based on gdb_realpath from GDB.
Copyright (C) 2003-2019 Free Software Foundation, Inc.
This file is part of the libiberty library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor,
Boston, MA 02110-1301, USA. */
/*
@deftypefn Replacement {const char*} lrealpath (const char *@var{name})
Given a pointer to a string containing a pathname, returns a canonical
version of the filename. Symlinks will be resolved, and ``.'' and ``..''
components will be simplified. The returned value will be allocated using
@code{malloc}, or @code{NULL} will be returned on a memory allocation error.
@end deftypefn
*/
#include "config.h"
#include "ansidecl.h"
#include "libiberty.h"
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
/* On GNU libc systems the declaration is only visible with _GNU_SOURCE. */
#if defined(HAVE_CANONICALIZE_FILE_NAME) \
&& defined(NEED_DECLARATION_CANONICALIZE_FILE_NAME)
extern char *canonicalize_file_name (const char *);
#endif
#if defined(HAVE_REALPATH)
# if defined (PATH_MAX)
# define REALPATH_LIMIT PATH_MAX
# else
# if defined (MAXPATHLEN)
# define REALPATH_LIMIT MAXPATHLEN
# endif
# endif
#else
/* cygwin has realpath, so it won't get here. */
# if defined (_WIN32)
# define WIN32_LEAN_AND_MEAN
# include <windows.h> /* for GetFullPathName */
# endif
#endif
char *
lrealpath (const char *filename)
{
/* Method 1: The system has a compile time upper bound on a filename
path. Use that and realpath() to canonicalize the name. This is
the most common case. Note that, if there isn't a compile time
upper bound, you want to avoid realpath() at all costs. */
#if defined(REALPATH_LIMIT)
{
char buf[REALPATH_LIMIT];
const char *rp = realpath (filename, buf);
if (rp == NULL)
rp = filename;
return strdup (rp);
}
#endif /* REALPATH_LIMIT */
/* Method 2: The host system (i.e., GNU) has the function
canonicalize_file_name() which malloc's a chunk of memory and
returns that, use that. */
#if defined(HAVE_CANONICALIZE_FILE_NAME)
{
char *rp = canonicalize_file_name (filename);
if (rp == NULL)
return strdup (filename);
else
return rp;
}
#endif
/* Method 3: Now we're getting desperate! The system doesn't have a
compile time buffer size and no alternative function. Query the
OS, using pathconf(), for the buffer limit. Care is needed
though, some systems do not limit PATH_MAX (return -1 for
pathconf()) making it impossible to pass a correctly sized buffer
to realpath() (it could always overflow). On those systems, we
skip this. */
#if defined (HAVE_REALPATH) && defined (HAVE_UNISTD_H)
{
/* Find out the max path size. */
long path_max = pathconf ("/", _PC_PATH_MAX);
if (path_max > 0)
{
/* PATH_MAX is bounded. */
char *buf, *rp, *ret;
buf = (char *) malloc (path_max);
if (buf == NULL)
return NULL;
rp = realpath (filename, buf);
ret = strdup (rp ? rp : filename);
free (buf);
return ret;
}
}
#endif
/* The MS Windows method. If we don't have realpath, we assume we
don't have symlinks and just canonicalize to a Windows absolute
path. GetFullPath converts ../ and ./ in relative paths to
absolute paths, filling in current drive if one is not given
or using the current directory of a specified drive (eg, "E:foo").
It also converts all forward slashes to back slashes. */
#if defined (_WIN32)
{
char buf[MAX_PATH];
char* basename;
DWORD len = GetFullPathName (filename, MAX_PATH, buf, &basename);
if (len == 0 || len > MAX_PATH - 1)
return strdup (filename);
else
{
/* The file system is case-preserving but case-insensitive,
Canonicalize to lowercase, using the codepage associated
with the process locale. */
CharLowerBuff (buf, len);
return strdup (buf);
}
}
#endif
/* This system is a lost cause, just duplicate the filename. */
return strdup (filename);
}
/* Return true when FD file descriptor exists. */
int
is_valid_fd (int fd)
{
#if defined(_WIN32)
HANDLE h = (HANDLE) _get_osfhandle (fd);
return h != (HANDLE) -1;
#else
return fcntl (fd, F_GETFD) >= 0;
#endif
}
|
