2 // Mono.Unix/UnixPath.cs
5 // Jonathan Pryor (jonpryor@vt.edu)
7 // (C) 2004-2006 Jonathan Pryor
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
30 using System
.Collections
;
36 public sealed class UnixPath
38 private UnixPath () {}
40 public static readonly char DirectorySeparatorChar
= '/';
41 public static readonly char AltDirectorySeparatorChar
= '/';
42 public static readonly char PathSeparator
= ':';
43 public static readonly char VolumeSeparatorChar
= '/';
45 private static readonly char[] _InvalidPathChars
= new char[]{};
47 public static char[] GetInvalidPathChars ()
49 return (char[]) _InvalidPathChars
.Clone ();
52 public static string Combine (string path1
, params string[] paths
)
55 throw new ArgumentNullException ("path1");
57 throw new ArgumentNullException ("paths");
58 if (path1
.IndexOfAny (_InvalidPathChars
) != -1)
59 throw new ArgumentException ("Illegal characters in path", "path1");
61 int len
= path1
.Length
;
63 for (int i
= 0; i
< paths
.Length
; ++i
) {
64 if (paths
[i
] == null)
65 throw new ArgumentNullException ("paths[" + i
+ "]");
66 if (paths
[i
].IndexOfAny (_InvalidPathChars
) != -1)
67 throw new ArgumentException ("Illegal characters in path", "paths[" + i
+ "]");
68 if (IsPathRooted (paths
[i
])) {
72 len
+= paths
[i
].Length
+ 1;
75 StringBuilder sb
= new StringBuilder (len
);
80 for (int i
= start
; i
< paths
.Length
; ++i
)
81 Combine (sb
, paths
[i
]);
82 return sb
.ToString ();
85 private static void Combine (StringBuilder path
, string part
)
87 if (path
.Length
> 0 && part
.Length
> 0) {
88 char end
= path
[path
.Length
-1];
89 if (end
!= DirectorySeparatorChar
&&
90 end
!= AltDirectorySeparatorChar
&&
91 end
!= VolumeSeparatorChar
)
92 path
.Append (DirectorySeparatorChar
);
97 public static string GetDirectoryName (string path
)
101 int lastDir
= path
.LastIndexOf (DirectorySeparatorChar
);
103 return path
.Substring (0, lastDir
);
109 public static string GetFileName (string path
)
111 if (path
== null || path
.Length
== 0)
114 int lastDir
= path
.LastIndexOf (DirectorySeparatorChar
);
116 return path
.Substring (lastDir
+1);
121 public static string GetFullPath (string path
)
123 path
= _GetFullPath (path
);
124 return GetCanonicalPath (path
);
127 private static string _GetFullPath (string path
)
130 throw new ArgumentNullException ("path");
131 if (!IsPathRooted (path
))
132 path
= UnixDirectoryInfo
.GetCurrentDirectory() + DirectorySeparatorChar
+ path
;
137 public static string GetCanonicalPath (string path
)
141 GetPathComponents (path
, out dirs
, out lastIndex
);
142 string end
= string.Join ("/", dirs
, 0, lastIndex
);
143 return IsPathRooted (path
) ? "/" + end
: end
;
146 private static void GetPathComponents (string path
,
147 out string[] components
, out int lastIndex
)
149 string [] dirs
= path
.Split (DirectorySeparatorChar
);
151 for (int i
= 0; i
< dirs
.Length
; ++i
) {
152 if (dirs
[i
] == "." || dirs
[i
] == string.Empty
) continue;
153 else if (dirs
[i
] == "..") {
154 if (target
!= 0) --target
;
158 dirs
[target
++] = dirs
[i
];
164 public static string GetPathRoot (string path
)
168 if (!IsPathRooted (path
))
173 public static string GetCompleteRealPath (string path
)
176 throw new ArgumentNullException ("path");
179 GetPathComponents (path
, out dirs
, out lastIndex
);
180 StringBuilder realPath
= new StringBuilder ();
181 if (dirs
.Length
> 0) {
182 string dir
= IsPathRooted (path
) ? "/" : "";
184 realPath
.Append (GetRealPath (dir
));
186 for (int i
= 1; i
< lastIndex
; ++i
) {
187 realPath
.Append ("/").Append (dirs
[i
]);
188 string p
= GetRealPath (realPath
.ToString());
189 realPath
.Remove (0, realPath
.Length
);
192 return realPath
.ToString ();
195 public static string GetRealPath (string path
)
198 string name
= ReadSymbolicLink (path
);
201 if (IsPathRooted (name
))
204 path
= GetDirectoryName (path
) + DirectorySeparatorChar
+ name
;
205 path
= GetCanonicalPath (path
);
210 // Read the specified symbolic link. If the file isn't a symbolic link,
211 // return null; otherwise, return the contents of the symbolic link.
213 // readlink(2) is horribly evil, as there is no way to query how big the
214 // symlink contents are. Consequently, it's trial and error...
215 internal static string ReadSymbolicLink (string path
)
217 StringBuilder buf
= new StringBuilder (256);
219 int r
= Native
.Syscall
.readlink (path
, buf
);
222 switch (e
= Native
.Stdlib
.GetLastError()) {
223 case Native
.Errno
.EINVAL
:
224 // path isn't a symbolic link
227 UnixMarshal
.ThrowExceptionForError (e
);
231 else if (r
== buf
.Capacity
) {
235 return buf
.ToString (0, r
);
239 // Read the specified symbolic link. If the file isn't a symbolic link,
240 // return null; otherwise, return the contents of the symbolic link.
242 // readlink(2) is horribly evil, as there is no way to query how big the
243 // symlink contents are. Consequently, it's trial and error...
244 private static string ReadSymbolicLink (string path
, out Native
.Errno errno
)
246 errno
= (Native
.Errno
) 0;
247 StringBuilder buf
= new StringBuilder (256);
249 int r
= Native
.Syscall
.readlink (path
, buf
);
251 errno
= Native
.Stdlib
.GetLastError ();
254 else if (r
== buf
.Capacity
) {
258 return buf
.ToString (0, r
);
262 public static string TryReadLink (string path
)
265 return ReadSymbolicLink (path
, out errno
);
268 public static string ReadLink (string path
)
271 path
= ReadSymbolicLink (path
, out errno
);
273 UnixMarshal
.ThrowExceptionForError (errno
);
277 public static bool IsPathRooted (string path
)
279 if (path
== null || path
.Length
== 0)
281 return path
[0] == DirectorySeparatorChar
;
284 internal static void CheckPath (string path
)
287 throw new ArgumentNullException ();
288 if (path
.Length
== 0)
289 throw new ArgumentException ("Path cannot contain a zero-length string", "path");
290 if (path
.IndexOfAny (_InvalidPathChars
) != -1)
291 throw new ArgumentException ("Invalid characters in path.", "path");