Get filename without extension in R

Question

I have a file:

ABCD.csv  

The length before the .csv is not fixed and vary in any length.

How can I extract the portion before the .csv?

Answer 1

There's a built in file_path_sans_ext from the standard install tools package that grabs the file without the extension.

tools::file_path_sans_ext("ABCD.csv") ## [1] "ABCD" 

Answer 2

basename will also remove the path leading to the file. And with this regex, any extension will be removed.

filepath <- "d:/Some Dir/ABCD.csv" sub(pattern = "(.*)\\..*$", replacement = "\\1", basename(filepath))  # [1] "ABCD" 

Or, using file_path_sans_ext as Tyler Rinker suggested:

file_path_sans_ext(basename(filepath))  # [1] "ABCD"