Erlang, Is it necessary to close the file here?

Question

When using file:read_file(x) is it necessary to close the returned file?

{ok, File} = file:read_file("maillog.sample"), 
file:close(File),

Answer 1

It is not a file, but the contents of the file that is returned. Thus, no file to close. Try changing the variable name to Data or similar as in the code below:

{ok, Data} = file:read_file("maillog.sample"),

Data will then have the contents of the file "maillog.sample". The function file:read_file/1 will open, read and close the file for you, all in one go.