path.jl
# This file is a part of Julia. License is MIT: https://julialang.org/license
export
abspath,
basename,
dirname,
expanduser,
contractuser,
homedir,
isabspath,
isdirpath,
joinpath,
normpath,
realpath,
relpath,
splitdir,
splitdrive,
splitext,
splitpath
if Sys.isunix()
const path_separator = "/"
const path_separator_re = r"/+"
const path_directory_re = r"(?:^|/)\.{0,2}$"
const path_dir_splitter = r"^(.*?)(/+)([^/]*)$"
const path_ext_splitter = r"^((?:.*/)?(?:\.|[^/\.])[^/]*?)(\.[^/\.]*|)$"
splitdrive(path::String) = ("",path)
elseif Sys.iswindows()
const path_separator = "\\"
const path_separator_re = r"[/\\]+"
const path_absolute_re = r"^(?:[A-Za-z]+:)?[/\\]"
const path_directory_re = r"(?:^|[/\\])\.{0,2}$"
const path_dir_splitter = r"^(.*?)([/\\]+)([^/\\]*)$"
const path_ext_splitter = r"^((?:.*[/\\])?(?:\.|[^/\\\.])[^/\\]*?)(\.[^/\\\.]*|)$"
function splitdrive(path::String)
m = match(r"^([^\\]+:|\\\\[^\\]+\\[^\\]+|\\\\\?\\UNC\\[^\\]+\\[^\\]+|\\\\\?\\[^\\]+:|)(.*)$", path)
String(m.captures[1]), String(m.captures[2])
end
else
error("path primitives for this OS need to be defined")
end
"""
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.
"""
splitdrive(path::AbstractString)
"""
homedir() -> AbstractString
Return the current user's home directory.
!!! note
`homedir` determines the home directory via `libuv`'s `uv_os_homedir`. For details
(for example on how to specify the home directory via environment variables), see the
[`uv_os_homedir` documentation](http://docs.libuv.org/en/v1.x/misc.html#c.uv_os_homedir).
"""
function homedir()
path_max = 1024
buf = Vector{UInt8}(undef, path_max)
sz = RefValue{Csize_t}(path_max + 1)
while true
rc = ccall(:uv_os_homedir, Cint, (Ptr{UInt8}, Ptr{Csize_t}), buf, sz)
if rc == 0
resize!(buf, sz[])
return String(buf)
elseif rc == Base.UV_ENOBUFS
resize!(buf, sz[] - 1)
else
error("unable to retrieve home directory")
end
end
end
if Sys.iswindows()
isabspath(path::String) = occursin(path_absolute_re, path)
else
isabspath(path::String) = startswith(path, '/')
end
"""
isabspath(path::AbstractString) -> Bool
Determine whether a path is absolute (begins at the root directory).
# Examples
```jldoctest
julia> isabspath("/home")
true
julia> isabspath("home")
false
```
"""
isabspath(path::AbstractString)
"""
isdirpath(path::AbstractString) -> Bool
Determine whether a path refers to a directory (for example, ends with a path separator).
# Examples
```jldoctest
julia> isdirpath("/home")
false
julia> isdirpath("/home/")
true
```
"""
isdirpath(path::String) = occursin(path_directory_re, splitdrive(path)[2])
"""
splitdir(path::AbstractString) -> (AbstractString, AbstractString)
Split a path into a tuple of the directory name and file name.
# Examples
```jldoctest
julia> splitdir("/home/myuser")
("/home", "myuser")
```
"""
function splitdir(path::String)
a, b = splitdrive(path)
_splitdir_nodrive(a,b)
end
# Common splitdir functionality without splitdrive, needed for splitpath.
_splitdir_nodrive(path::String) = _splitdir_nodrive("", path)
function _splitdir_nodrive(a::String, b::String)
m = match(path_dir_splitter,b)
m === nothing && return (a,b)
a = string(a, isempty(m.captures[1]) ? m.captures[2][1] : m.captures[1])
a, String(m.captures[3])
end
"""
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
```jldoctest
julia> dirname("/home/myuser")
"/home"
julia> dirname("/home/myuser/")
"/home/myuser"
```
See also: [`basename`](@ref)
"""
dirname(path::AbstractString) = splitdir(path)[1]
"""
basename(path::AbstractString) -> AbstractString
Get the file name part of a path.
# Examples
```jldoctest
julia> basename("/home/myuser/example.jl")
"example.jl"
```
See also: [`dirname`](@ref)
"""
basename(path::AbstractString) = splitdir(path)[2]
"""
splitext(path::AbstractString) -> (AbstractString, AbstractString)
If the last component of a path contains a dot, split the path into everything before the
dot and everything including and after the dot. Otherwise, return a tuple of the argument
unmodified and the empty string.
# Examples
```jldoctest
julia> splitext("/home/myuser/example.jl")
("/home/myuser/example", ".jl")
julia> splitext("/home/myuser/example")
("/home/myuser/example", "")
```
"""
function splitext(path::String)
a, b = splitdrive(path)
m = match(path_ext_splitter, b)
m === nothing && return (path,"")
a*m.captures[1], String(m.captures[2])
end
function pathsep(paths::AbstractString...)
for path in paths
m = match(path_separator_re, String(path))
m !== nothing && return m.match[1:1]
end
return path_separator
end
"""
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.
!!! compat "Julia 1.1"
This function requires at least Julia 1.1.
# Examples
```jldoctest
julia> splitpath("/home/myuser/example.jl")
4-element Array{String,1}:
"/"
"home"
"myuser"
"example.jl"
```
"""
function splitpath(p::String)
drive, p = splitdrive(p)
out = String[]
isempty(p) && (pushfirst!(out,p)) # "" means the current directory.
while !isempty(p)
dir, base = _splitdir_nodrive(p)
dir == p && (pushfirst!(out, dir); break) # Reached root node.
if !isempty(base) # Skip trailing '/' in basename
pushfirst!(out, base)
end
p = dir
end
if !isempty(drive) # Tack the drive back on to the first element.
out[1] = drive*out[1] # Note that length(out) is always >= 1.
end
return out
end
joinpath(a::AbstractString) = a
"""
joinpath(parts...) -> AbstractString
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.
# Examples
```jldoctest
julia> joinpath("/home/myuser", "example.jl")
"/home/myuser/example.jl"
```
"""
joinpath(a::AbstractString, b::AbstractString, c::AbstractString...) = joinpath(joinpath(a,b), c...)
function joinpath(a::String, b::String)
isabspath(b) && return b
A, a = splitdrive(a)
B, b = splitdrive(b)
!isempty(B) && A != B && return string(B,b)
C = isempty(B) ? A : B
isempty(a) ? string(C,b) :
occursin(path_separator_re, a[end:end]) ? string(C,a,b) :
string(C,a,pathsep(a,b),b)
end
joinpath(a::AbstractString, b::AbstractString) = joinpath(String(a), String(b))
"""
normpath(path::AbstractString) -> AbstractString
Normalize a path, removing "." and ".." entries.
# Examples
```jldoctest
julia> normpath("/home/myuser/../example.jl")
"/home/example.jl"
```
"""
function normpath(path::String)
isabs = isabspath(path)
isdir = isdirpath(path)
drive, path = splitdrive(path)
parts = split(path, path_separator_re)
filter!(x->!isempty(x) && x!=".", parts)
while true
clean = true
for j = 1:length(parts)-1
if parts[j] != ".." && parts[j+1] == ".."
deleteat!(parts, j:j+1)
clean = false
break
end
end
clean && break
end
if isabs
while !isempty(parts) && parts[1] == ".."
popfirst!(parts)
end
elseif isempty(parts)
push!(parts, ".")
end
path = join(parts, path_separator)
if isabs
path = path_separator*path
end
if isdir && !isdirpath(path)
path *= path_separator
end
string(drive,path)
end
normpath(a::AbstractString, b::AbstractString...) = normpath(joinpath(a,b...))
"""
abspath(path::AbstractString) -> AbstractString
Convert a path to an absolute path by adding the current directory if necessary.
Also normalizes the path as in [`normpath`](@ref).
"""
abspath(a::String) = normpath(isabspath(a) ? a : joinpath(pwd(),a))
"""
abspath(path::AbstractString, paths::AbstractString...) -> AbstractString
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...))`.
"""
abspath(a::AbstractString, b::AbstractString...) = abspath(joinpath(a,b...))
if Sys.iswindows()
function realpath(path::AbstractString)
h = ccall(:CreateFileW, stdcall, Int, (Cwstring, UInt32, UInt32, Ptr{Cvoid}, UInt32, UInt32, Int),
path, 0, 0x03, C_NULL, 3, 0x02000000, 0)
windowserror(:realpath, h == -1)
try
buf = Vector{UInt16}(undef, 256)
oldlen = len = length(buf)
while len >= oldlen
len = ccall(:GetFinalPathNameByHandleW, stdcall, UInt32, (Int, Ptr{UInt16}, UInt32, UInt32),
h, buf, (oldlen=len)-1, 0x0)
windowserror(:realpath, iszero(len))
resize!(buf, len) # strips NUL terminator on last call
end
if 4 < len < 264 && 0x005c == buf[1] == buf[2] == buf[4] && 0x003f == buf[3]
Base._deletebeg!(buf, 4) # omit \\?\ prefix for paths < MAXPATH in length
end
return transcode(String, buf)
finally
windowserror(:realpath, iszero(ccall(:CloseHandle, stdcall, Cint, (Int,), h)))
end
end
function longpath(path::AbstractString)
p = cwstring(path)
buf = zeros(UInt16, length(p))
while true
n = ccall((:GetLongPathNameW, "kernel32"), stdcall,
UInt32, (Ptr{UInt16}, Ptr{UInt16}, UInt32),
p, buf, length(buf))
windowserror(:longpath, n == 0)
x = n < length(buf) # is the buffer big enough?
resize!(buf, n) # shrink if x, grow if !x
x && return transcode(String, buf)
end
end
else # !windows
function realpath(path::AbstractString)
p = ccall(:realpath, Ptr{UInt8}, (Cstring, Ptr{UInt8}), path, C_NULL)
systemerror(:realpath, p == C_NULL)
str = unsafe_string(p)
Libc.free(p)
return str
end
end # os-test
"""
realpath(path::AbstractString) -> AbstractString
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.)
"""
realpath(path::AbstractString)
if Sys.iswindows()
# on windows, ~ means "temporary file"
expanduser(path::AbstractString) = path
contractuser(path::AbstractString) = path
else
function expanduser(path::AbstractString)
y = iterate(path)
y === nothing && return path
c, i = y
c != '~' && return path
y = iterate(path, i)
y === nothing && return homedir()
y[1] == '/' && return homedir() * path[i:end]
throw(ArgumentError("~user tilde expansion not yet implemented"))
end
function contractuser(path::AbstractString)
home = homedir()
if path == home
return "~"
elseif startswith(path, home)
return joinpath("~", relpath(path, home))
else
return path
end
end
end
"""
expanduser(path::AbstractString) -> AbstractString
On Unix systems, replace a tilde character at the start of a path with the current user's home directory.
"""
expanduser(path::AbstractString)
"""
contractuser(path::AbstractString) -> AbstractString
On Unix systems, if the path starts with `homedir()`, replace it with a tilde character.
"""
contractuser(path::AbstractString)
"""
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`.
"""
function relpath(path::String, startpath::String = ".")
isempty(path) && throw(ArgumentError("`path` must be specified"))
isempty(startpath) && throw(ArgumentError("`startpath` must be specified"))
curdir = "."
pardir = ".."
path == startpath && return curdir
path_arr = split(abspath(path), path_separator_re)
start_arr = split(abspath(startpath), path_separator_re)
i = 0
while i < min(length(path_arr), length(start_arr))
i += 1
if path_arr[i] != start_arr[i]
i -= 1
break
end
end
pathpart = join(path_arr[i+1:something(findlast(x -> !isempty(x), path_arr), 0)], path_separator)
prefix_num = something(findlast(x -> !isempty(x), start_arr), 0) - i - 1
if prefix_num >= 0
prefix = pardir * path_separator
relpath_ = isempty(pathpart) ?
(prefix^prefix_num) * pardir :
(prefix^prefix_num) * pardir * path_separator * pathpart
else
relpath_ = pathpart
end
return isempty(relpath_) ? curdir : relpath_
end
relpath(path::AbstractString, startpath::AbstractString) =
relpath(String(path), String(startpath))
for f in (:isabspath, :isdirpath, :splitdir, :splitdrive, :splitext, :normpath, :abspath)
@eval $f(path::AbstractString) = $f(String(path))
end