Path

This module provides conveniences for manipulating or retrieving file system paths.

The functions in this module may receive a chardata as argument (i.e. a string or a list of characters / string) and will always return a string (encoded in UTF-8). If a binary is given, in whatever encoding, its encoding will be kept.

The majority of the functions in this module do not interact with the file system, except for a few functions that require it (like wildcard/2 and expand/1).

Function absname/1

Converts the given path to an absolute one. Unlike expand/1, no attempt is made to resolve .., . or ~.

Examples

Unix-like operating systems

Path.absname("foo")
# => "/usr/local/foo"

Path.absname("../x")
# => "/usr/local/../x"

Windows

Path.absname("foo")
# => "D:/usr/local/foo"

Path.absname("../x")
# => "D:/usr/local/../x"

Function absname/2

Builds a path from relative_to to path.

If path is already an absolute path, relative_to is ignored. See also relative_to/2.

Unlike expand/2, no attempt is made to resolve .., . or ~.

Examples

Path.absname("foo", "bar")

Path.absname("../x", "bar")

Function basename/1

Returns the last component of the path or the path itself if it does not contain any directory separators.

Examples

Path.basename("foo")

Path.basename("foo/bar")

Path.basename("/")

Function basename/2

Returns the last component of path with the extension stripped.

This function should be used to remove a specific extension which may or may not be there.

Examples

Path.basename("~/foo/bar.ex", ".ex")

Path.basename("~/foo/bar.exs", ".ex")

Path.basename("~/foo/bar.old.ex", ".ex")

Function dirname/1

Returns the directory component of path.

Examples

Path.dirname("/foo/bar.ex")

Path.dirname("/foo/bar/baz.ex")

Path.dirname("/foo/bar/")

Path.dirname("bar.ex")

Function expand/1

Converts the path to an absolute one and expands any . and .. characters and a leading ~.

Examples

Path.expand("/foo/bar/../baz")
# => "/foo/baz"

Function expand/2

Expands the path relative to the path given as the second argument expanding any . and .. characters.

If the path is already an absolute path, relative_to is ignored.

Note that this function treats a path with a leading ~ as an absolute one.

The second argument is first expanded to an absolute path.

Examples

# Assuming that the absolute path to baz is /quux/baz
Path.expand("foo/bar/../bar", "baz")
# => "/quux/baz/foo/bar"

Path.expand("foo/bar/../bar", "/baz")
# => "/baz/foo/bar"

Path.expand("/foo/bar/../bar", "/baz")
# => "/foo/bar"

Function extname/1

Returns the extension of the last component of path.

The behaviour of this function changed in Erlang/OTP 24 for filenames starting with a dot and without an extension. For example, for a file named “.gitignore”, extname/1 now returns an empty string, while it would return “.gitignore” in previous Erlang/OTP versions. This was done to match the behaviour of rootname/1, which would return “.gitignore” as its name (and therefore it cannot also be an extension).

See basename/1 and rootname/1 for related functions to extract information from paths.

Examples

Path.extname("foo.erl")

Path.extname("~/foo/bar")

Function join/1

Joins a list of paths.

This function should be used to convert a list of paths to a path. Note that any trailing slash is removed when joining.

Examples

Path.join(["~", "foo"])

Path.join(["foo"])

Path.join(["/", "foo", "bar/"])

Function join/2

Joins two paths.

The right path will always be expanded to its relative format and any trailing slash will be removed when joining.

Examples

Path.join("foo", "bar")

Path.join("/foo", "/bar/")

The functions in this module support chardata, so giving a list will treat it as a single entity:

Path.join("foo", ["bar", "fiz"])

Path.join(["foo", "bar"], "fiz")

Function relative/1

Forces the path to be a relative path.

Examples

Unix-like operating systems

# => "usr/local/bin"
Path.relative("/usr/local/bin")
# => "usr/local/bin"
Path.relative("usr/local/bin")
# => "../usr/local/bin"
Path.relative("../usr/local/bin")

Windows

# => "usr/local/bin"
Path.relative("D:/usr/local/bin")
# => "usr/local/bin"
Path.relative("usr/local/bin")
# => "bar.ex"
Path.relative("D:bar.ex")
# => "bar/foo.ex"
Path.relative("/bar/foo.ex")

Function relative_to/2

Returns the given path relative to the given from path.

In other words, this function tries to strip the from prefix from path.

This function does not query the file system, so it assumes no symlinks between the paths.

In case a direct relative path cannot be found, it returns the original path.

Examples

Path.relative_to("/usr/local/foo", "/usr/local")

Path.relative_to("/usr/local/foo", "/")

Path.relative_to("/usr/local/foo", "/etc")

Path.relative_to("/usr/local/foo", "/usr/local/foo")

Function relative_to_cwd/1

Convenience to get the path relative to the current working directory.

If, for some reason, the current working directory cannot be retrieved, this function returns the given path.

Function rootname/1

Returns the path with the extension stripped.

Examples

Path.rootname("/foo/bar")

Path.rootname("/foo/bar.ex")

Function rootname/2

Returns the path with the extension stripped.

This function should be used to remove a specific extension which may or may not be there.

Examples

Path.rootname("/foo/bar.erl", ".erl")

Path.rootname("/foo/bar.erl", ".ex")

Function split/1

Splits the path into a list at the path separator.

If an empty string is given, returns an empty list.

On Windows, path is split on both “\” and “/“ separators and the driver letter, if there is one, is always returned in lowercase.

Examples

Path.split("")

Path.split("foo")

Path.split("/foo/bar")

Function type/1

Returns the path type.

Examples

Unix-like operating systems

# => :absolute
Path.type("/")
# => :absolute
Path.type("/usr/local/bin")
# => :relative
Path.type("usr/local/bin")
# => :relative
Path.type("../usr/local/bin")
# => :relative
Path.type("~/file")

Windows

# => :absolute
Path.type("D:/usr/local/bin")
# => :relative
Path.type("usr/local/bin")
# => :volumerelative
Path.type("D:bar.ex")
# => :volumerelative
Path.type("/bar/foo.ex")

Function wildcard/2

Traverses paths according to the given glob expression and returns a list of matches.

The wildcard looks like an ordinary path, except that the following “wildcard characters” are interpreted in a special way:

• ? - matches one character.

• * - matches any number of characters up to the end of the filename, the next dot, or the next slash.

• ** - two adjacent *‘s used as a single pattern will match all files and zero or more directories and subdirectories.

• [char1,char2,...] - matches any of the characters listed; two characters separated by a hyphen will match a range of characters. Do not add spaces before and after the comma as it would then match paths containing the space character itself.

• {item1,item2,...} - matches one of the alternatives. Do not add spaces before and after the comma as it would then match paths containing the space character itself.

Other characters represent themselves. Only paths that haveexactly the same character in the same position will match. Note that matching is case-sensitive: "a" will not match "A".

Directory separators must always be written as /, even on Windows. You may call Path.expand/1 to normalize the path before invoking this function.

By default, the patterns * and ? do not match files starting with a dot .. See the :match_dot option in the “Options” section below.

Options

• :match_dot - (boolean) if false, the special wildcard characters * and ? will not match files starting with a dot (.). If true, files starting with a . will not be treated specially. Defaults to false.

Examples

Imagine you have a directory called projects with three Elixir projects inside of it: elixir, ex_doc, and plug. You can find all .beam files inside the ebin directory of each project as follows:

Path.wildcard("projects/*/ebin/**/*.beam")

If you want to search for both .beam and .app files, you could do:

Path.wildcard("projects/*/ebin/**/*.{beam,app}")