Path Operations: Concatenation (concat), Extraction of sub-paths, etc.

Path Operations: Concatenation (concat), Extraction of sub-paths, etc.

[Nordlöw]

Hey again, Emacs Powerusers!

I am looking for convenience functions for path operations, typically

- concatenation of paths: (path-concat "/usr/" "/lib") => "/usr/lib/"
- extraction of sub-paths: (path-before "/usr/lib/" "/lib/") => "usr/"
- extraction of sub-paths: (path-after "/usr/lib/X11" "lib") => "X11/"
- full path to local file name: (path-local "/etc/passwd") => "passwd"
- full path to containing directory path: (path-dir "/etc/passwd") =>
"/etc/"

If possible results should be standardized/canonicalized, that is
- directories always end with "/"
- non-absolute paths always begin directly with the top-most directory
name without the "/"


/Nordlöw

Re: Path Operations: Concatenation (concat), Extraction of sub-paths, etc.

[Kai Grossjohann]

Nordlöw <per.nordlow@gmail.com> writes:

> - concatenation of paths: (path-concat "/usr/" "/lib") => "/usr/lib/"

Not exactly, but close: expand-file-name

> - extraction of sub-paths: (path-before "/usr/lib/" "/lib/") => "usr/"

Not exactly, but close, perhaps: file-name-directory,
file-name-nondirectory.

> - extraction of sub-paths: (path-after "/usr/lib/X11" "lib") => "X11/"

See above.

> - full path to local file name: (path-local "/etc/passwd") => "passwd"

file-name-nondirectory

> - full path to containing directory path: (path-dir "/etc/passwd") =>
> "/etc/"

file-name-directory

> If possible results should be standardized/canonicalized, that is
> - directories always end with "/"

file-name-as-directory

> - non-absolute paths always begin directly with the top-most directory
> name without the "/"

Hm.  There must be a function to strip leading "./" and "/./" in the
middle, but I don't know what it is.  There is file-truename which
might do this as a side effect.

Kai

Re: Path Operations: Concatenation (concat), Extraction of sub-paths, etc.

[Stefan Monnier]

>> - full path to local file name: (path-local "/etc/passwd") => "passwd"
> file-name-nondirectory

Or file-relative-name, depending.


        Stefan