How to extract the extension from a filename in Julia?

Question

I am looking for a simple way to extract the extension (.txt, .py, .jl, etc) from a file in Julia. I looked through the Julia docs but didn't see anything specifically built for this.

Ashlaring

It’s OK to Ask and Answer Your Own Questions: stackoverflow.blog/2011/07/01/… – Ashlaring

It absolutely is. People get so upset about that sometimes, but it really is very much in line with the goals of the site as a whole. – Aged

Answer 1

Use splitext from Filesystem

julia> splitext("/home/myuser/example.jl") 
("/home/myuser/example", ".jl") 

julia> splitext("/home/myuser/example") 
("/home/myuser/example", "")

Archilochus

Answer 2

This is a faster alternative, if that is of any importance:

file_extension(file::String) = file[findlast(==('.'), file)+1:end]

Aida

Answer 3

While there is no built in Julia function to do this, what you can do is given the filename, split the string on a period "." as follows:

julia> filePath = "some/path/my_program.jl"
"some/path/my_program.jl"

julia> split(filePath, ".")[2]
"jl"

Ashlaring

I would use split(filePath, ".")[end] to be sure to get the file extension.. – Negus

This fails when there are dots in the file path. end is indeed the best solution. – Catholicon