expanduser/
lib.rs

1#[macro_use] extern crate lazy_static;
2extern crate pwd;
3extern crate dirs;
4
5use std::{
6    io,
7    path::{PathBuf, MAIN_SEPARATOR}
8};
9
10use pwd::Passwd;
11
12lazy_static! {
13static ref PREFIX: String = format!("~{}", MAIN_SEPARATOR);
14}
15
16/// Takes a string-like thing and tries to turn it into a PathBuf while expanding `~`'s and `~user`'s
17/// into the user's home directory
18///
19/// # Example
20///
21/// ```rust
22/// extern crate expanduser;
23///
24/// use expanduser::expanduser;
25///
26/// # fn main() -> ::std::io::Result<()> {
27/// # let old_home = ::std::env::var("HOME").expect("no HOME set");
28/// # ::std::env::set_var("HOME", "/home/foo");
29/// let path = expanduser("~/path/to/directory")?;
30/// # ::std::env::set_var("HOME", &old_home);
31/// assert_eq!(path.display().to_string(), "/home/foo/path/to/directory");
32/// #   Ok(())
33/// # }
34/// ```
35pub fn expanduser<S: AsRef<str>>(s: S) -> io::Result<PathBuf> {
36    _expand_user(s.as_ref())
37}
38
39fn _expand_user(s: &str) -> io::Result<PathBuf> {
40    Ok(match s {
41        // matches an exact "~"
42        s if s == "~" => {
43            home_dir()?
44        },
45        // matches paths that start with `~/`
46        s if s.starts_with(&*PREFIX) => {
47            let home = home_dir()?;
48            home.join(&s[2..])
49        },
50        // matches paths that start with `~` but not `~/`, might be a `~username/` path
51        s if s.starts_with("~") => {
52            let mut parts = s[1..].splitn(2, MAIN_SEPARATOR);
53            let user = parts.next()
54                            .ok_or_else(|| io::Error::new(io::ErrorKind::Other, "malformed path"))?;
55            let user = Passwd::from_name(&user)
56                              .map_err(|_| io::Error::new(io::ErrorKind::Other, "error searching for user"))?
57                              .ok_or_else(|| io::Error::new(io::ErrorKind::Other, format!("user '{}', does not exist", &user)))?;
58            if let Some(ref path) = parts.next() {
59                PathBuf::from(user.dir).join(&path)
60            } else {
61                PathBuf::from(user.dir)
62            }
63        },
64        // nothing to expand, just make a PathBuf
65        s => PathBuf::from(s)
66    })
67}
68
69fn home_dir() -> io::Result<PathBuf> {
70    dirs::home_dir().ok_or_else(|| io::Error::new(io::ErrorKind::Other, "no home directory is set"))
71}
72
73#[cfg(test)]
74mod tests {
75    use std::env;
76    use super::*;
77
78    // Until I figure out a better to way to test this stuff in isolation, it is necessary to run
79    // this using `cargo test -- --test-threads 1`, otherwise you will probably get race conditions
80    // from the HOME manipulation
81
82    #[test]
83    fn test_success() {
84        let old_home = env::var("HOME").expect("no home dir set");
85        let new_home = "/home/foo";
86        env::set_var("HOME", new_home);
87        let path = expanduser("~/path/to/directory");
88        env::set_var("HOME", old_home);
89        assert_eq!(path.expect("io error"), PathBuf::from("/home/foo/path/to/directory"));
90    }
91
92    #[test]
93    fn test_only_tilde() {
94        let old_home = env::var("HOME").expect("no home dir set");
95        let new_home = "/home/foo";
96        env::set_var("HOME", new_home);
97        let pathstr = "~";
98        let path = expanduser(pathstr);
99        env::set_var("HOME", old_home);
100        assert_eq!(path.expect("io error"), PathBuf::from("/home/foo"));
101    }
102
103    #[test]
104    fn test_user() {
105        let user = env::var("USER").expect("no user set");
106        if user.len() < 1 {
107            panic!("user is empty");
108        }
109        let home = dirs::home_dir().expect("no home directory set");
110        let pathstr = format!("~{}/path/to/directory", &user);
111        let path = expanduser(&pathstr).expect("io error");
112        assert_eq!(path, home.join("path/to/directory"));
113    }
114
115    #[test]
116    fn test_just_tilde_user() {
117        let user = env::var("USER").expect("no user set");
118        if user.len() < 1 {
119            panic!("user is empty");
120        }
121        let home = dirs::home_dir().expect("no home directory set");
122        let pathstr = format!("~{}", &user);
123        let path = expanduser(&pathstr).expect("io error");
124        assert_eq!(path, home);
125    }
126
127    #[test]
128    fn test_fail_malformed_path() {
129        let pathstr = "~\ruses-invalid-path-char";
130        let err = expanduser(&pathstr).unwrap_err();
131        let kind = err.kind();
132        assert_eq!(kind, io::ErrorKind::Other);
133    }
134
135    #[test]
136    #[should_panic]
137    fn test_user_does_not_exist() {
138        expanduser("~user_that_should_not_exist/path/to/directory")
139                        .expect("user does not exist");
140    }
141}
expanduser/lib.rs

expanduser/
lib.rs
