mktemp{,dir}: add parent directory option

For example, `mktemp(dir)` will create a temporary file in the `dir`
directory.

NEWS.md

@@ -292,6 +292,9 @@ Library improvements
  * New function `relpath` returns a relative filepath to path either from the current
  directory or from an optional start directory ([#10893]).
 
+ * `mktemp` and `mktempdir` now take an optional argument to set which
+ directory the temporary file or directory is created in.
+
 Deprecated or removed
 ---------------------
 

base/file.jl

@@ -143,16 +143,18 @@ end
 tempdir() = dirname(tempname())
 
 # Create and return the name of a temporary file along with an IOStream
-function mktemp()
- b = joinpath(tempdir(), "tmpXXXXXX")
- p = ccall(:mkstemp, Int32, (Ptr{UInt8}, ), b) # modifies b
+function mktemp(parent=tempdir())
+ b = joinpath(parent, "tmpXXXXXX")
+ p = ccall(:mkstemp, Int32, (Ptr{UInt8},), b) # modifies b
+ systemerror(:mktemp, p == -1)
  return (b, fdio(p, true))
 end
 
 # Create and return the name of a temporary directory
-function mktempdir()
- b = joinpath(tempdir(), "tmpXXXXXX")
- p = ccall(:mkdtemp, Ptr{UInt8}, (Ptr{UInt8}, ), b)
+function mktempdir(parent=tempdir())
+ b = joinpath(parent, "tmpXXXXXX")
+ p = ccall(:mkdtemp, Ptr{UInt8}, (Ptr{UInt8},), b)
+ systemerror(:mktempdir, p == C_NULL)
  return bytestring(p)
 end
 end
@@ -178,18 +180,17 @@ function tempname(temppath::AbstractString,uunique::UInt32)
  resize!(tname,lentname+1)
  return utf8(UTF16String(tname))
 end
-function mktemp()
- filename = tempname()
+function mktemp(parent=tempdir())
+ filename = tempname(parent, UInt32(0))
  return (filename, open(filename,"r+"))
 end
-function mktempdir()
+function mktempdir(parent=tempdir())
  seed::UInt32 = rand(UInt32)
- dir = tempdir()
  while true
  if (seed & typemax(UInt16)) == 0
  seed += 1
  end
- filename = tempname(dir, seed)
+ filename = tempname(parent, seed)
  ret = ccall(:_wmkdir, Int32, (Ptr{UInt16},), utf16(filename))
  if ret == 0
  return filename

doc/stdlib/file.rst

@@ -147,14 +147,14 @@
 
  Obtain the path of a temporary directory (possibly shared with other processes).
 
-.. function:: mktemp()
+.. function:: mktemp([parent=tempdir()])
 
  Returns ``(path, io)``, where ``path`` is the path of a new temporary file
- and ``io`` is an open file object for this path.
+ in ``parent`` and ``io`` is an open file object for this path.
 
-.. function:: mktempdir()
+.. function:: mktempdir([parent=tempdir()])
 
- Create a temporary directory and return its path.
+ Create a temporary directory in the ``parent`` directory and return its path.
 
 .. function:: isblockdev(path) -> Bool
 

test/file.jl

@@ -112,6 +112,17 @@ cp(newfile, c_file)
 @test isfile(c_file)
 @test_throws SystemError rm(c_tmpdir)
 
+# create temp dir in specific directory
+d_tmpdir = mktempdir(c_tmpdir)
+@test isdir(d_tmpdir)
+@test Base.samefile(dirname(d_tmpdir), c_tmpdir)
+
+# create temp file in specific directory
+d_tmpfile,f = mktemp(c_tmpdir)
+close(f)
+@test isfile(d_tmpfile)
+@test Base.samefile(dirname(d_tmpfile), c_tmpdir)
+
 rm(c_tmpdir, recursive=true)
 @test !isdir(c_tmpdir)