( string filename [, int use_include_path] )
Reads a file, decompresses it and writes it to standard output.
readgzfile() can be used to read a file which is not in
gzip format; in this case readgzfile() will directly
read from the file without decompression.
Returns the number of (uncompressed) bytes read from the file. If
an error occurs, FALSE is returned and unless the function was
called as @readgzfile, an error message is