Thanks for the reply. I ran the suggested statement:  grep -r _parse_file XML-LibXML-1.69: XML-LibXML-1.69/LibXML.xs and a couple of other variations for the 'grep' command, hoping to find results, but no luck. I also searched for the LibXML.xs file in entire server, but it doesn't exist.

However, when I searched on just 'LibXML', I stumbled upon the LibXML.so file, which seems to contain the text for  _parse_file. Probably, it contains the implementation of the _parse_file() subroutine? However, since it is a binary code, I couldn't decipher much.