Question

When calling the pathExtension method on a string that contains something such as “example.tar.gz” I get “.gz” as the result. I can do some string manipulation to get the real extension, but I’m number wondering if there is a built in method that I’m overlooking? (I have checked the docs, but I don’t see anything).

Answer 1

Obviously pathExtension is working as expected in this case. The documentation for pathExtension says:

The path extension is the portion of the last path component which
follows the final period, if there is one.

I can see where you are coming from with your example of a tarred gzipped file. However, I would say that .gz is the extension. Unzipping the file (with gzip) will result in a .tar file which can be extracted with tar.

I assume that the convention of naming files with the .tar.gz extension started before tar was able to also perform the gzip compression. The gzip application appends .gz to the filename of the file being compressed. For example, gzipping a log file, access.log, will result in a file called access.log.gz.

The .tgz extension has been used for tarred gzipped files particularly where the filename needs to be preserved on file systems that would mangle the extension (e.g. DOS).