# Filesystem

Base.Filesystem.cdMethod
cd(dir::AbstractString=homedir())

Set the current working directory.

Examples

julia> cd("/home/JuliaUser/Projects/julia")

julia> pwd()
"/home/JuliaUser/Projects/julia"

julia> cd()

julia> pwd()
"/home/JuliaUser"
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Base.Filesystem.cdMethod
cd(f::Function, dir::AbstractString=homedir())

Temporarily change the current working directory to dir, apply function f and finally return to the original directory.

Examples

julia> pwd()
"/home/JuliaUser"

34-element Array{String,1}:
".circleci"
".freebsdci.sh"
".git"
".gitattributes"
".github"
⋮
"test"
"ui"
"usr"
"usr-staging"

julia> pwd()
"/home/JuliaUser"
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Base.Filesystem.readdirFunction
readdir(dir::AbstractString=pwd();
join::Bool = false,
sort::Bool = true,
) -> Vector{String}

Return the names in the directory dir or the current working directory if not given. When join is false, readdir returns just the names in the directory as is; when join is true, it returns joinpath(dir, name) for each name so that the returned strings are full paths. If you want to get absolute paths back, call readdir with an absolute directory path and join set to true.

By default, readdir sorts the list of names it returns. If you want to skip sorting the names and get them in the order that the file system lists them, you can use readdir(dir, sort=false) to opt out of sorting.

Julia 1.4

The join and sort keyword arguments require at least Julia 1.4.

Examples

julia> cd("/home/JuliaUser/dev/julia")

30-element Array{String,1}:
".appveyor.yml"
".git"
".gitattributes"
⋮
"ui"
"usr"
"usr-staging"

30-element Array{String,1}:
"/home/JuliaUser/dev/julia/.appveyor.yml"
"/home/JuliaUser/dev/julia/.git"
"/home/JuliaUser/dev/julia/.gitattributes"
⋮
"/home/JuliaUser/dev/julia/ui"
"/home/JuliaUser/dev/julia/usr"
"/home/JuliaUser/dev/julia/usr-staging"

145-element Array{String,1}:
".gitignore"
"Base.jl"
"Enums.jl"
⋮
"version_git.sh"
"views.jl"
"weakkeydict.jl"

145-element Array{String,1}:
"base/.gitignore"
"base/Base.jl"
"base/Enums.jl"
⋮
"base/version_git.sh"
"base/views.jl"
"base/weakkeydict.jl"

145-element Array{String,1}:
"/home/JuliaUser/dev/julia/base/.gitignore"
"/home/JuliaUser/dev/julia/base/Base.jl"
"/home/JuliaUser/dev/julia/base/Enums.jl"
⋮
"/home/JuliaUser/dev/julia/base/version_git.sh"
"/home/JuliaUser/dev/julia/base/views.jl"
"/home/JuliaUser/dev/julia/base/weakkeydict.jl"
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Base.Filesystem.walkdirFunction
walkdir(dir; topdown=true, follow_symlinks=false, onerror=throw)

Return an iterator that walks the directory tree of a directory. The iterator returns a tuple containing (rootpath, dirs, files). The directory tree can be traversed top-down or bottom-up. If walkdir or stat encounters a IOError it will rethrow the error by default. A custom error handling function can be provided through onerror keyword argument. onerror is called with a IOError as argument.

Examples

for (root, dirs, files) in walkdir(".")
println("Directories in $root") for dir in dirs println(joinpath(root, dir)) # path to directories end println("Files in$root")
for file in files
println(joinpath(root, file)) # path to files
end
end
julia> mkpath("my/test/dir");

julia> itr = walkdir("my");

julia> (root, dirs, files) = first(itr)
("my", ["test"], String[])

julia> (root, dirs, files) = first(itr)
("my/test", ["dir"], String[])

julia> (root, dirs, files) = first(itr)
("my/test/dir", String[], String[])
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Base.Filesystem.mkdirFunction
mkdir(path::AbstractString; mode::Unsigned = 0o777)

Make a new directory with name path and permissions mode. mode defaults to 0o777, modified by the current file creation mask. This function never creates more than one directory. If the directory already exists, or some intermediate directories do not exist, this function throws an error. See mkpath for a function which creates all required intermediate directories. Return path.

Examples

julia> mkdir("testingdir")
"testingdir"

julia> cd("testingdir")

julia> pwd()
"/home/JuliaUser/testingdir"
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Base.Filesystem.mkpathFunction
mkpath(path::AbstractString; mode::Unsigned = 0o777)

Create all directories in the given path, with permissions mode. mode defaults to 0o777, modified by the current file creation mask. Unlike mkdir, mkpath does not error if path (or parts of it) already exists. Return path.

Examples

julia> mkdir("testingdir")
"testingdir"

julia> cd("testingdir")

julia> pwd()
"/home/JuliaUser/testingdir"

julia> mkpath("my/test/dir")
"my/test/dir"

1-element Array{String,1}:
"my"

julia> cd("my")

1-element Array{String,1}:
"test"

1-element Array{String,1}:
"dir"
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Base.Filesystem.symlinkFunction
symlink(target::AbstractString, link::AbstractString; dir_target = false)

Creates a symbolic link to target with the name link.

On Windows, symlinks must be explicitly declared as referring to a directory or not. If target already exists, by default the type of link will be auto- detected, however if target does not exist, this function defaults to creating a file symlink unless dir_target is set to true. Note that if the user sets dir_target but target exists and is a file, a directory symlink will still be created, but dereferencing the symlink will fail, just as if the user creates a file symlink (by calling symlink() with dir_target set to false before the directory is created) and tries to dereference it to a directory.

Additionally, there are two methods of making a link on Windows; symbolic links and junction points. Junction points are slightly more efficient, but do not support relative paths, so if a relative directory symlink is requested (as denoted by isabspath(target) returning false) a symlink will be used, else a junction point will be used. Best practice for creating symlinks on Windows is to create them only after the files/directories they reference are already created.

Note

This function raises an error under operating systems that do not support soft symbolic links, such as Windows XP.

Julia 1.6

The dir_target keyword argument was added in Julia 1.6. Prior to this, symlinks to nonexistant paths on windows would always be file symlinks, and relative symlinks to directories were not supported.

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Base.Filesystem.chmodFunction
chmod(path::AbstractString, mode::Integer; recursive::Bool=false)

Change the permissions mode of path to mode. Only integer modes (e.g. 0o777) are currently supported. If recursive=true and the path is a directory all permissions in that directory will be recursively changed. Return path.

Note

Prior to Julia 1.6, this did not correctly manipulate filesystem ACLs on Windows, therefore it would only set read-only bits on files. It now is able to manipulate ACLs.

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Base.Filesystem.chownFunction
chown(path::AbstractString, owner::Integer, group::Integer=-1)

Change the owner and/or group of path to owner and/or group. If the value entered for owner or group is -1 the corresponding ID will not change. Only integer owners and groups are currently supported. Return path.

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Base.Libc.RawFDType
RawFD

Primitive type which wraps the native OS file descriptor. RawFDs can be passed to methods like stat to discover information about the underlying file, and can also be used to open streams, with the RawFD describing the OS file backing the stream.

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Base.statFunction
stat(file)

Returns a structure whose fields contain information about the file. The fields of the structure are:

NameDescription
descThe path or OS file descriptor
sizeThe size (in bytes) of the file
deviceID of the device that contains the file
inodeThe inode number of the file
modeThe protection mode of the file
uidThe user id of the owner of the file
gidThe group id of the file owner
rdevIf this file refers to a device, the ID of the device it refers to
blksizeThe file-system preferred block size for the file
blocksThe number of such blocks allocated
ctimeUnix timestamp of when the file's metadata was changed
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Base.Filesystem.lstatFunction
lstat(file)

Like stat, but for symbolic links gets the info for the link itself rather than the file it refers to. This function must be called on a file path rather than a file object or a file descriptor.

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Base.Filesystem.cpFunction
cp(src::AbstractString, dst::AbstractString; force::Bool=false, follow_symlinks::Bool=false)

Copy the file, link, or directory from src to dst. force=true will first remove an existing dst.

If follow_symlinks=false, and src is a symbolic link, dst will be created as a symbolic link. If follow_symlinks=true and src is a symbolic link, dst will be a copy of the file or directory src refers to. Return dst.

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Base.downloadFunction
download(url::AbstractString, [path::AbstractString = tempname()]) -> path

Download a file from the given url, saving it to the location path, or if not specified, a temporary path. Returns the path of the downloaded file.

Note

Since Julia 1.6, this function is deprecated and is just a thin wrapper around Downloads.download. In new code, you should use that function directly instead of calling this.

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Base.Filesystem.mvFunction
mv(src::AbstractString, dst::AbstractString; force::Bool=false)

Move the file, link, or directory from src to dst. force=true will first remove an existing dst. Return dst.

Examples

julia> write("hello.txt", "world");

julia> mv("hello.txt", "goodbye.txt")
"goodbye.txt"

false

"world"

julia> write("hello.txt", "world2");

julia> mv("hello.txt", "goodbye.txt")
ERROR: ArgumentError: 'goodbye.txt' exists. force=true is required to remove 'goodbye.txt' before moving.
Stacktrace:
[1] #checkfor_mv_cp_cptree#10(::Bool, ::Function, ::String, ::String, ::String) at ./file.jl:293
[...]

julia> mv("hello.txt", "goodbye.txt", force=true)
"goodbye.txt"

julia> rm("goodbye.txt");

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Base.Filesystem.rmFunction
rm(path::AbstractString; force::Bool=false, recursive::Bool=false)

Delete the file, link, or empty directory at the given path. If force=true is passed, a non-existing path is not treated as error. If recursive=true is passed and the path is a directory, then all contents are removed recursively.

Examples

julia> mkpath("my/test/dir");

julia> rm("my", recursive=true)

julia> rm("this_file_does_not_exist", force=true)

julia> rm("this_file_does_not_exist")
ERROR: IOError: unlink("this_file_does_not_exist"): no such file or directory (ENOENT)
Stacktrace:
[...]
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Base.Filesystem.touchFunction
touch(path::AbstractString)

Update the last-modified timestamp on a file to the current time.

If the file does not exist a new file is created.

Return path.

Examples

julia> write("my_little_file", 2);

julia> mtime("my_little_file")
1.5273815391135583e9

julia> touch("my_little_file");

julia> mtime("my_little_file")
1.527381559163435e9

We can see the mtime has been modified by touch.

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Base.Filesystem.tempnameFunction
tempname(parent=tempdir(); cleanup=true) -> String

Generate a temporary file path. This function only returns a path; no file is created. The path is likely to be unique, but this cannot be guaranteed due to the very remote posibility of two simultaneous calls to tempname generating the same file name. The name is guaranteed to differ from all files already existing at the time of the call to tempname.

When called with no arguments, the temporary name will be an absolute path to a temporary name in the system temporary directory as given by tempdir(). If a parent directory argument is given, the temporary path will be in that directory instead.

The cleanup option controls whether the process attempts to delete the returned path automatically when the process exits. Note that the tempname function does not create any file or directory at the returned location, so there is nothing to cleanup unless you create a file or directory there. If you do and clean is true it will be deleted upon process termination.

Julia 1.4

The parent and cleanup arguments were added in 1.4. Prior to Julia 1.4 the path tempname would never be cleaned up at process termination.

Warning

This can lead to security holes if another process obtains the same file name and creates the file before you are able to. Open the file with JL_O_EXCL if this is a concern. Using mktemp() is also recommended instead.

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Base.Filesystem.tempdirFunction
tempdir()

Gets the path of the temporary directory. On Windows, tempdir() uses the first environment variable found in the ordered list TMP, TEMP, USERPROFILE. On all other operating systems, tempdir() uses the first environment variable found in the ordered list TMPDIR, TMP, TEMP, and TEMPDIR. If none of these are found, the path "/tmp" is used.

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Base.Filesystem.mktempMethod
mktemp(parent=tempdir(); cleanup=true) -> (path, io)

Return (path, io), where path is the path of a new temporary file in parent and io is an open file object for this path. The cleanup option controls whether the temporary file is automatically deleted when the process exits.

Julia 1.3

The cleanup keyword argument was added in Julia 1.3. Relatedly, starting from 1.3, Julia will remove the temporary paths created by mktemp when the Julia process exits, unless cleanup is explicitly set to false.

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Base.Filesystem.mktempdirMethod
mktempdir(parent=tempdir(); prefix="jl_", cleanup=true) -> path

Create a temporary directory in the parent directory with a name constructed from the given prefix and a random suffix, and return its path. Additionally, any trailing X characters may be replaced with random characters. If parent does not exist, throw an error. The cleanup option controls whether the temporary directory is automatically deleted when the process exits.

Julia 1.2

The prefix keyword argument was added in Julia 1.2.

Julia 1.3

The cleanup keyword argument was added in Julia 1.3. Relatedly, starting from 1.3, Julia will remove the temporary paths created by mktempdir when the Julia process exits, unless cleanup is explicitly set to false.

See also: mktemp, mkdir.

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Base.Filesystem.isfileFunction
isfile(path) -> Bool

Return true if path is a regular file, false otherwise.

Examples

julia> isfile(homedir())
false

julia> f = open("test_file.txt", "w");

julia> isfile(f)
true

julia> close(f); rm("test_file.txt")

See also isdir and ispath.

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Base.Filesystem.dirnameFunction
dirname(path::AbstractString) -> AbstractString

Get the directory part of a path. Trailing characters ('/' or '\') in the path are counted as part of the path.

Examples

julia> dirname("/home/myuser")
"/home"

julia> dirname("/home/myuser/")
"/home/myuser"

See also basename.

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Base.Filesystem.basenameFunction
basename(path::AbstractString) -> AbstractString

Get the file name part of a path.

Note

This function differs slightly from the Unix basename program, where trailing slashes are ignored, i.e. \$ basename /foo/bar/ returns bar, whereas basename in Julia returns an empty string "".

Examples

julia> basename("/home/myuser/example.jl")
"example.jl"

julia> basename("/home/myuser/")
""

See also dirname.

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Base.Filesystem.isabspathFunction
isabspath(path::AbstractString) -> Bool

Determine whether a path is absolute (begins at the root directory).

Examples

julia> isabspath("/home")
true

julia> isabspath("home")
false
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Base.Filesystem.isdirpathFunction
isdirpath(path::AbstractString) -> Bool

Determine whether a path refers to a directory (for example, ends with a path separator).

Examples

julia> isdirpath("/home")
false

julia> isdirpath("/home/")
true
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Base.Filesystem.joinpathFunction
joinpath(parts::AbstractString...) -> String
joinpath(parts::Vector{AbstractString}) -> String
joinpath(parts::Tuple{AbstractString}) -> String

Join path components into a full path. If some argument is an absolute path or (on Windows) has a drive specification that doesn't match the drive computed for the join of the preceding paths, then prior components are dropped.

Note on Windows since there is a current directory for each drive, joinpath("c:", "foo") represents a path relative to the current directory on drive "c:" so this is equal to "c:foo", not "c:\foo". Furthermore, joinpath treats this as a non-absolute path and ignores the drive letter casing, hence joinpath("C:\A","c:b") = "C:\A\b".

Examples

julia> joinpath("/home/myuser", "example.jl")
"/home/myuser/example.jl"
julia> joinpath(["/home/myuser", "example.jl"])
"/home/myuser/example.jl"
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Base.Filesystem.abspathFunction
abspath(path::AbstractString) -> String

Convert a path to an absolute path by adding the current directory if necessary. Also normalizes the path as in normpath.

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abspath(path::AbstractString, paths::AbstractString...) -> String

Convert a set of paths to an absolute path by joining them together and adding the current directory if necessary. Equivalent to abspath(joinpath(path, paths...)).

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Base.Filesystem.normpathFunction
normpath(path::AbstractString) -> String

Normalize a path, removing "." and ".." entries.

Examples

julia> normpath("/home/myuser/../example.jl")
"/home/example.jl"
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normpath(path::AbstractString, paths::AbstractString...) -> String

Convert a set of paths to a normalized path by joining them together and removing "." and ".." entries. Equivalent to normpath(joinpath(path, paths...)).

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Base.Filesystem.realpathFunction
realpath(path::AbstractString) -> String

Canonicalize a path by expanding symbolic links and removing "." and ".." entries. On case-insensitive case-preserving filesystems (typically Mac and Windows), the filesystem's stored case for the path is returned.

(This function throws an exception if path does not exist in the filesystem.)

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Base.Filesystem.relpathFunction
relpath(path::AbstractString, startpath::AbstractString = ".") -> AbstractString

Return a relative filepath to path either from the current directory or from an optional start directory. This is a path computation: the filesystem is not accessed to confirm the existence or nature of path or startpath.

On Windows, case sensitivity is applied to every part of the path except drive letters. If path and startpath refer to different drives, the absolute path of path is returned.

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Base.Filesystem.expanduserFunction
expanduser(path::AbstractString) -> AbstractString

On Unix systems, replace a tilde character at the start of a path with the current user's home directory.

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Base.Filesystem.splitdirFunction
splitdir(path::AbstractString) -> (AbstractString, AbstractString)

Split a path into a tuple of the directory name and file name.

Examples

julia> splitdir("/home/myuser")
("/home", "myuser")
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Base.Filesystem.splitdriveFunction
splitdrive(path::AbstractString) -> (AbstractString, AbstractString)

On Windows, split a path into the drive letter part and the path part. On Unix systems, the first component is always the empty string.

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Base.Filesystem.splitextFunction
splitext(path::AbstractString) -> (AbstractString, AbstractString)

If the last component of a path contains one or more dots, split the path into everything before the last dot and everything including and after the dot. Otherwise, return a tuple of the argument unmodified and the empty string. "splitext" is short for "split extension".

Examples

julia> splitext("/home/myuser/example.jl")
("/home/myuser/example", ".jl")

julia> splitext("/home/myuser/example.tar.gz")
("/home/myuser/example.tar", ".gz")

julia> splitext("/home/my.user/example")
("/home/my.user/example", "")
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Base.Filesystem.splitpathFunction
splitpath(path::AbstractString) -> Vector{String}

Split a file path into all its path components. This is the opposite of joinpath. Returns an array of substrings, one for each directory or file in the path, including the root directory if present.

Julia 1.1

This function requires at least Julia 1.1.

Examples

julia> splitpath("/home/myuser/example.jl")
4-element Vector{String}:
"/"
"home"
"myuser"
"example.jl"`
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