which/
lib.rs

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
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
//! which
//!
//! A Rust equivalent of Unix command `which(1)`.
//! # Example:
//!
//! To find which rustc executable binary is using:
//!
//! ```no_run
//! use which::which;
//! use std::path::PathBuf;
//!
//! let result = which::which("rustc").unwrap();
//! assert_eq!(result, PathBuf::from("/usr/bin/rustc"));
//!
//! ```

#[cfg(windows)]
#[macro_use]
extern crate lazy_static;

mod checker;
mod error;
mod finder;
#[cfg(windows)]
mod helper;

#[cfg(feature = "regex")]
use regex::Regex;
use std::env;
use std::fmt;
use std::path;

use std::ffi::OsStr;

use crate::checker::{CompositeChecker, ExecutableChecker, ExistedChecker};
pub use crate::error::*;
use crate::finder::Finder;

/// Find a exectable binary's path by name.
///
/// If given an absolute path, returns it if the file exists and is executable.
///
/// If given a relative path, returns an absolute path to the file if
/// it exists and is executable.
///
/// If given a string without path separators, looks for a file named
/// `binary_name` at each directory in `$PATH` and if it finds an executable
/// file there, returns it.
///
/// # Example
///
/// ```no_run
/// use which::which;
/// use std::path::PathBuf;
///
/// let result = which::which("rustc").unwrap();
/// assert_eq!(result, PathBuf::from("/usr/bin/rustc"));
///
/// ```
pub fn which<T: AsRef<OsStr>>(binary_name: T) -> Result<path::PathBuf> {
    which_all(binary_name).and_then(|mut i| i.next().ok_or(Error::CannotFindBinaryPath))
}

/// Find all binaries with `binary_name` in the path list `paths`, using `cwd` to resolve relative paths.
pub fn which_all<T: AsRef<OsStr>>(binary_name: T) -> Result<impl Iterator<Item = path::PathBuf>> {
    let cwd = env::current_dir().map_err(|_| Error::CannotGetCurrentDir)?;

    which_in_all(binary_name, env::var_os("PATH"), cwd)
}

/// Find all binaries matching a regular expression in a the system PATH.
///
/// # Arguments
///
/// * `regex` - A regular expression to match binaries with
///
/// # Examples
///
/// ```no_run
/// use regex::Regex;
/// use which::which;
/// use std::path::PathBuf;
///
/// let re = Regex::new(r"python\d$").unwrap();
/// let binaries: Vec<PathBuf> = which::which_re(re).unwrap().collect();
/// let python_paths = vec![PathBuf::from("/usr/bin/python2"), PathBuf::from("/usr/bin/python3")];
/// assert_eq!(binaries, python_paths);
/// ```
#[cfg(feature = "regex")]
pub fn which_re(regex: Regex) -> Result<impl Iterator<Item = path::PathBuf>> {
    which_re_in(regex, env::var_os("PATH"))
}

/// Find `binary_name` in the path list `paths`, using `cwd` to resolve relative paths.
pub fn which_in<T, U, V>(binary_name: T, paths: Option<U>, cwd: V) -> Result<path::PathBuf>
where
    T: AsRef<OsStr>,
    U: AsRef<OsStr>,
    V: AsRef<path::Path>,
{
    which_in_all(binary_name, paths, cwd)
        .and_then(|mut i| i.next().ok_or(Error::CannotFindBinaryPath))
}

/// Find all binaries matching a regular expression in a list of paths.
///
/// # Arguments
///
/// * `regex` - A regular expression to match binaries with
/// * `paths` - A string containing the paths to search
///             (separated in the same way as the PATH environment variable)
///
/// # Examples
///
/// ```no_run
/// use regex::Regex;
/// use which::which;
/// use std::path::PathBuf;
///
/// let re = Regex::new(r"python\d$").unwrap();
/// let paths = Some("/usr/bin:/usr/local/bin");
/// let binaries: Vec<PathBuf> = which::which_re_in(re, paths).unwrap().collect();
/// let python_paths = vec![PathBuf::from("/usr/bin/python2"), PathBuf::from("/usr/bin/python3")];
/// assert_eq!(binaries, python_paths);
/// ```
#[cfg(feature = "regex")]
pub fn which_re_in<T>(regex: Regex, paths: Option<T>) -> Result<impl Iterator<Item = path::PathBuf>>
where
    T: AsRef<OsStr>,
{
    let binary_checker = CompositeChecker::new()
        .add_checker(Box::new(ExistedChecker::new()))
        .add_checker(Box::new(ExecutableChecker::new()));

    let finder = Finder::new();

    finder.find_re(regex, paths, binary_checker)
}

/// Find all binaries with `binary_name` in the path list `paths`, using `cwd` to resolve relative paths.
pub fn which_in_all<T, U, V>(
    binary_name: T,
    paths: Option<U>,
    cwd: V,
) -> Result<impl Iterator<Item = path::PathBuf>>
where
    T: AsRef<OsStr>,
    U: AsRef<OsStr>,
    V: AsRef<path::Path>,
{
    let binary_checker = CompositeChecker::new()
        .add_checker(Box::new(ExistedChecker::new()))
        .add_checker(Box::new(ExecutableChecker::new()));

    let finder = Finder::new();

    finder.find(binary_name, paths, cwd, binary_checker)
}

/// An owned, immutable wrapper around a `PathBuf` containing the path of an executable.
///
/// The constructed `PathBuf` is the output of `which` or `which_in`, but `which::Path` has the
/// advantage of being a type distinct from `std::path::Path` and `std::path::PathBuf`.
///
/// It can be beneficial to use `which::Path` instead of `std::path::Path` when you want the type
/// system to enforce the need for a path that exists and points to a binary that is executable.
///
/// Since `which::Path` implements `Deref` for `std::path::Path`, all methods on `&std::path::Path`
/// are also available to `&which::Path` values.
#[derive(Clone, PartialEq)]
pub struct Path {
    inner: path::PathBuf,
}

impl Path {
    /// Returns the path of an executable binary by name.
    ///
    /// This calls `which` and maps the result into a `Path`.
    pub fn new<T: AsRef<OsStr>>(binary_name: T) -> Result<Path> {
        which(binary_name).map(|inner| Path { inner })
    }

    /// Returns the paths of all executable binaries by a name.
    ///
    /// this calls `which_all` and maps the results into `Path`s.
    pub fn all<T: AsRef<OsStr>>(binary_name: T) -> Result<impl Iterator<Item = Path>> {
        which_all(binary_name).map(|inner| inner.map(|inner| Path { inner }))
    }

    /// Returns the path of an executable binary by name in the path list `paths` and using the
    /// current working directory `cwd` to resolve relative paths.
    ///
    /// This calls `which_in` and maps the result into a `Path`.
    pub fn new_in<T, U, V>(binary_name: T, paths: Option<U>, cwd: V) -> Result<Path>
    where
        T: AsRef<OsStr>,
        U: AsRef<OsStr>,
        V: AsRef<path::Path>,
    {
        which_in(binary_name, paths, cwd).map(|inner| Path { inner })
    }

    /// Returns all paths of an executable binary by name in the path list `paths` and using the
    /// current working directory `cwd` to resolve relative paths.
    ///
    /// This calls `which_in_all` and maps the results into a `Path`.
    pub fn all_in<T, U, V>(
        binary_name: T,
        paths: Option<U>,
        cwd: V,
    ) -> Result<impl Iterator<Item = Path>>
    where
        T: AsRef<OsStr>,
        U: AsRef<OsStr>,
        V: AsRef<path::Path>,
    {
        which_in_all(binary_name, paths, cwd).map(|inner| inner.map(|inner| Path { inner }))
    }

    /// Returns a reference to a `std::path::Path`.
    pub fn as_path(&self) -> &path::Path {
        self.inner.as_path()
    }

    /// Consumes the `which::Path`, yielding its underlying `std::path::PathBuf`.
    pub fn into_path_buf(self) -> path::PathBuf {
        self.inner
    }
}

impl fmt::Debug for Path {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(&self.inner, f)
    }
}

impl std::ops::Deref for Path {
    type Target = path::Path;

    fn deref(&self) -> &path::Path {
        self.inner.deref()
    }
}

impl AsRef<path::Path> for Path {
    fn as_ref(&self) -> &path::Path {
        self.as_path()
    }
}

impl AsRef<OsStr> for Path {
    fn as_ref(&self) -> &OsStr {
        self.as_os_str()
    }
}

impl Eq for Path {}

impl PartialEq<path::PathBuf> for Path {
    fn eq(&self, other: &path::PathBuf) -> bool {
        self.inner == *other
    }
}

impl PartialEq<Path> for path::PathBuf {
    fn eq(&self, other: &Path) -> bool {
        *self == other.inner
    }
}

/// An owned, immutable wrapper around a `PathBuf` containing the _canonical_ path of an
/// executable.
///
/// The constructed `PathBuf` is the result of `which` or `which_in` followed by
/// `Path::canonicalize`, but `CanonicalPath` has the advantage of being a type distinct from
/// `std::path::Path` and `std::path::PathBuf`.
///
/// It can be beneficial to use `CanonicalPath` instead of `std::path::Path` when you want the type
/// system to enforce the need for a path that exists, points to a binary that is executable, is
/// absolute, has all components normalized, and has all symbolic links resolved
///
/// Since `CanonicalPath` implements `Deref` for `std::path::Path`, all methods on
/// `&std::path::Path` are also available to `&CanonicalPath` values.
#[derive(Clone, PartialEq)]
pub struct CanonicalPath {
    inner: path::PathBuf,
}

impl CanonicalPath {
    /// Returns the canonical path of an executable binary by name.
    ///
    /// This calls `which` and `Path::canonicalize` and maps the result into a `CanonicalPath`.
    pub fn new<T: AsRef<OsStr>>(binary_name: T) -> Result<CanonicalPath> {
        which(binary_name)
            .and_then(|p| p.canonicalize().map_err(|_| Error::CannotCanonicalize))
            .map(|inner| CanonicalPath { inner })
    }

    /// Returns the canonical paths of an executable binary by name.
    ///
    /// This calls `which_all` and `Path::canonicalize` and maps the results into `CanonicalPath`s.
    pub fn all<T: AsRef<OsStr>>(
        binary_name: T,
    ) -> Result<impl Iterator<Item = Result<CanonicalPath>>> {
        which_all(binary_name).map(|inner| {
            inner.map(|inner| {
                inner
                    .canonicalize()
                    .map_err(|_| Error::CannotCanonicalize)
                    .map(|inner| CanonicalPath { inner })
            })
        })
    }

    /// Returns the canonical path of an executable binary by name in the path list `paths` and
    /// using the current working directory `cwd` to resolve relative paths.
    ///
    /// This calls `which_in` and `Path::canonicalize` and maps the result into a `CanonicalPath`.
    pub fn new_in<T, U, V>(binary_name: T, paths: Option<U>, cwd: V) -> Result<CanonicalPath>
    where
        T: AsRef<OsStr>,
        U: AsRef<OsStr>,
        V: AsRef<path::Path>,
    {
        which_in(binary_name, paths, cwd)
            .and_then(|p| p.canonicalize().map_err(|_| Error::CannotCanonicalize))
            .map(|inner| CanonicalPath { inner })
    }

    /// Returns all of the canonical paths of an executable binary by name in the path list `paths` and
    /// using the current working directory `cwd` to resolve relative paths.
    ///
    /// This calls `which_in_all` and `Path::canonicalize` and maps the result into a `CanonicalPath`.
    pub fn all_in<T, U, V>(
        binary_name: T,
        paths: Option<U>,
        cwd: V,
    ) -> Result<impl Iterator<Item = Result<CanonicalPath>>>
    where
        T: AsRef<OsStr>,
        U: AsRef<OsStr>,
        V: AsRef<path::Path>,
    {
        which_in_all(binary_name, paths, cwd).map(|inner| {
            inner.map(|inner| {
                inner
                    .canonicalize()
                    .map_err(|_| Error::CannotCanonicalize)
                    .map(|inner| CanonicalPath { inner })
            })
        })
    }

    /// Returns a reference to a `std::path::Path`.
    pub fn as_path(&self) -> &path::Path {
        self.inner.as_path()
    }

    /// Consumes the `which::CanonicalPath`, yielding its underlying `std::path::PathBuf`.
    pub fn into_path_buf(self) -> path::PathBuf {
        self.inner
    }
}

impl fmt::Debug for CanonicalPath {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(&self.inner, f)
    }
}

impl std::ops::Deref for CanonicalPath {
    type Target = path::Path;

    fn deref(&self) -> &path::Path {
        self.inner.deref()
    }
}

impl AsRef<path::Path> for CanonicalPath {
    fn as_ref(&self) -> &path::Path {
        self.as_path()
    }
}

impl AsRef<OsStr> for CanonicalPath {
    fn as_ref(&self) -> &OsStr {
        self.as_os_str()
    }
}

impl Eq for CanonicalPath {}

impl PartialEq<path::PathBuf> for CanonicalPath {
    fn eq(&self, other: &path::PathBuf) -> bool {
        self.inner == *other
    }
}

impl PartialEq<CanonicalPath> for path::PathBuf {
    fn eq(&self, other: &CanonicalPath) -> bool {
        *self == other.inner
    }
}