Add dirname(path, n)

[rikhuijzer]

Going up multiple directories doesn't seem to be in the Julia base yet. As far as I know, using normpath is the best way, and that is what people typically use for the project root

project_root = normpath(joinpath(@__FILE__, "..", ".."))

from https://stackoverflow.com/questions/35466572. Alternatively, people use dirname multiple times

project_root = dirname(dirname(@__FILE___))

see https://github.com/search?q=filename%3A*.jl+dirname%28dirname%28.

With this PR, I propose to add an integer as second parameter for dirname. Then, we could write

project_root = dirname(@__FILE__, 2)

Or, for longer paths

julia> dirname("/a/b/c/d/e", 3)
"a/b"

[stevengj]

Maybe just n <= 0 ? path : dirname(dirname(path), n-1)

[stevengj]

Or dirname^n(path)... wasn’t there a general proposal to use exponentiation for function iteration at some point? #34251 (comment)

[rikhuijzer]

Or dirname^n(path)... wasn’t there a general proposal to use exponentiation for function iteration at some point? #34251 (comment)

That sounds like a good generalized solution. So, lets close this PR? If not, then I'll change the definition to a recursive one.

[stevengj]

I'll push a PR to add function^n, and we'll see what the reception is.

[rikhuijzer]

👍 Then, I'll close this PR for now.