LFE Friday - filelib:is_file/1

This week's LFE Friday was translated with permission from the Erlang Thursday series by Steven Proctor. This week's translator: Robert Virding.

Today's LFE Friday is filelib:is_file/1.

filelib:is_file/1 takes a string representing a filename, and returns a true or false depending on if the name refers to a file or directory.

This can be useful if you are having to read from a configuration file and need to ensure that the file or directory exists before trying to process it, so that you can give a nice error message before quitting, instead of just causing a system error to be raised.

> (filelib:is_file "foo")
false
> (filelib:is_file "tmp")
false
> (filelib:is_file "src")
true
> (filelib:is_file "README.md")
true
> (filelib:is_file "/usr/local/bin")
true
> (filelib:is_file "/usr/local/var")
false
> (filelib:is_file ".")
true
> (filelib:is_file "..")
true

filelib:is_file/1 can also take a atom, or even a deeplist(), representing the filename as well.

> (filelib:is_file 'foo)
false
> (filelib:is_file '("/usr" (/local /bin)))
true

-Proctor, Robert