Thanks, igelkott, for adressing the console-part of my post. Can you please explain to me in more basic terms what your suggestion is? I am fairly new to Linux and hence don't quite understand what the issue is you are pointing at.
The file I intend to operate on, however, has been generated with the 'cat' command in the shell concatenating other files generated under Linux. Not sure, therefore, if the inter-operating-system issue applies here.
Thanks again -
Pat