(index<- ) ./librustc/util/fs.rs
git branch: * master 5200215 auto merge of #14035 : alexcrichton/rust/experimental, r=huonw
modified: Sat Apr 19 11:22:39 2014
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 use std::io;
12 use std::io::fs;
13 use std::os;
14
15 /// Returns an absolute path in the filesystem that `path` points to. The
16 /// returned path does not contain any symlinks in its hierarchy.
17 pub fn realpath(original: &Path) -> io::IoResult<Path> {
18 static MAX_LINKS_FOLLOWED: uint = 256;
19 let original = os::make_absolute(original);
20
21 // Right now lstat on windows doesn't work quite well
22 if cfg!(windows) {
23 return Ok(original)
24 }
25
26 let result = original.root_path();
27 let mut result = result.expect("make_absolute has no root_path");
28 let mut followed = 0;
29
30 for part in original.components() {
31 result.push(part);
32
33 loop {
34 if followed == MAX_LINKS_FOLLOWED {
35 return Err(io::standard_error(io::InvalidInput))
36 }
37
38 match fs::lstat(&result) {
39 Err(..) => break,
40 Ok(ref stat) if stat.kind != io::TypeSymlink => break,
41 Ok(..) => {
42 followed += 1;
43 let path = try!(fs::readlink(&result));
44 result.pop();
45 result.push(path);
46 }
47 }
48 }
49 }
50
51 return Ok(result);
52 }
53
54 #[cfg(not(windows), test)]
55 mod test {
56 use std::io;
57 use std::io::fs::{File, symlink, mkdir, mkdir_recursive};
58 use super::realpath;
59 use std::io::TempDir;
60
61 #[test]
62 fn realpath_works() {
63 let tmpdir = TempDir::new("rustc-fs").unwrap();
64 let tmpdir = realpath(tmpdir.path()).unwrap();
65 let file = tmpdir.join("test");
66 let dir = tmpdir.join("test2");
67 let link = dir.join("link");
68 let linkdir = tmpdir.join("test3");
69
70 File::create(&file).unwrap();
71 mkdir(&dir, io::UserRWX).unwrap();
72 symlink(&file, &link).unwrap();
73 symlink(&dir, &linkdir).unwrap();
74
75 assert!(realpath(&tmpdir).unwrap() == tmpdir);
76 assert!(realpath(&file).unwrap() == file);
77 assert!(realpath(&link).unwrap() == file);
78 assert!(realpath(&linkdir).unwrap() == dir);
79 assert!(realpath(&linkdir.join("link")).unwrap() == file);
80 }
81
82 #[test]
83 fn realpath_works_tricky() {
84 let tmpdir = TempDir::new("rustc-fs").unwrap();
85 let tmpdir = realpath(tmpdir.path()).unwrap();
86
87 let a = tmpdir.join("a");
88 let b = a.join("b");
89 let c = b.join("c");
90 let d = a.join("d");
91 let e = d.join("e");
92 let f = a.join("f");
93
94 mkdir_recursive(&b, io::UserRWX).unwrap();
95 mkdir_recursive(&d, io::UserRWX).unwrap();
96 File::create(&f).unwrap();
97 symlink(&Path::new("../d/e"), &c).unwrap();
98 symlink(&Path::new("../f"), &e).unwrap();
99
100 assert!(realpath(&c).unwrap() == f);
101 assert!(realpath(&e).unwrap() == f);
102 }
103 }