Wolfram: File Path Functions

Dir Path Separator

Note: WolframLang path functions use a dir separator compatible to your operating system. On linux and Mac, it's slash, on Microsoft Windows its blackslash. But blackslash in WolframLang string is a escape character, so, it needs to be double backslash.

Note: Microsoft Windows supports slash for dir path. So, you can always use slash for input.

Get Dir Path

DirectoryName

DirectoryName[path]

return the directory path.

DirectoryName

(* tested on Microsoft Windows *)

DirectoryName[ "c:/a/b/c.html" ]
(* c:\a\b\ *)

FileNameDrop[path]

drop the last part of path.

FileNameDrop

FileNameDrop[ "c:/a/b/c.html" ]

(* c:\a\b *)

FileNameDrop[ "c:/a/b/" ]
(* c:\a *)

Get File Name Part of Path

FileNameTake[path]

return the filename part.

FileNameTake

FileNameTake[ "c:/Users/xah/.emacs.d/temp/x20241205_1038_4eb.wl" ]
(* x20241205_1038_4eb.wl *)

Get File Base Name

FileBaseName[path]

return the file base name. (i.e. sans dir and sans file extension)

FileBaseName

FileBaseName["c:/Users/xah/abc.txt"]
(* abc *)

Get File Name Extension

FileExtension[path]

return the file extension. (without the dot)

FileExtension

FileExtension["c:/a/b/c.txt"]
(* txt *)

Get File Path Depth

FileNameDepth[path]

return the depth of file path.

FileNameDepth

FileNameDepth["c:/Users/xah/abc.txt"]
(* 4 *)

FileNameDepth["c:\\Users\\xah\\abc.txt"]
(* 4 *)

(* pathological example *)
FileNameDepth["c:///abc.txt"]
(* 4 *)

(* it basically count the number of separators plus 1 *)

Split File Path to List

FileNameSplit[path]

split the file path into a list.

FileNameSplit

FileNameSplit["c:/a/b"]
(* {c:, a, b} *)

FileNameSplit["c:\\a\\b"]
(* {c:, a, b} *)

FileNameSplit["/a/b"]
(* {, a, b} *)

(* edge case *)
FileNameSplit["c:/a/b//c"]
(* {c:, a, b, , c} *)

Join Path

FileNameJoin[dir, name]

join directory and file name into a single path.

FileNameJoin

(* all example tested on Microsoft Windows *)

FileNameJoin[ {"a","b","c"} ]
(* a\b\c *)

FileNameJoin[ {"a/","b"} ]
(* a\b *)

(* dir separator is added if none exist *)
FileNameJoin[ {"a","b"} ]
(* a\b *)

(* extra dir separator is removed *)
FileNameJoin[ {"a/","/b"} ]
(* a\b *)

(* extra dir separator is removed *)
FileNameJoin[ {"a//","b"} ]
(* a\b *)

Expand File Path (Relative Path to Full)

ExpandFileName[name]

return full path (name relative to current directory).

ExpandFileName

ExpandFileName[ "c.html" ]
(* C:\Users\xah\.emacs.d\temp\c.html *)
(* on Microsoft Windows *)
(* basically prepend dir path to arg *)

Get Absolute File Path

AbsoluteFileName[name]

return a absolute full path.

file must exist

AbsoluteFileName

(* tested on Microsoft Windows *)

(* relative name to full path *)
AbsoluteFileName[ "xx.py" ]
(* C:\Users\xah\.emacs.d\temp\xx.py *)

AbsoluteFileName[ "c:/Users/xah/web/xahlee_info/M/index.html" ]
(* C:\Users\xah\web\xahlee_info\M\index.html *)

(* if file no exist, return $Failed *)
AbsoluteFileName[ "xxx" ]
(* $Failed *)