To answer your PS: > P.S. For our previous class we used bison++/flex++ to parse the cif file. Are > their any other better ways/tools one can use to write a cif parser? I'm a great fan of ANTLR (formerly PCCTS) for this kind of work. I used PCCTS v1.33 to write a restricted STAR file parser a while back. I'm using Berkley yacc for another piece of work at the moment, and I keep wishing that I was using PCCTS..... See http://www.antlr.org/ for pointers to ANTLR resources, including the newsgroup. PRECCX is also well worth checking out, particularly if you are a fan of literate programming. See http://www.comlab.ox.ac.uk/archive/redo/precc.html. Have fun, Peter. ======================================================================== Peter Keller. | "Research without indebtedness is European Bioinformatics Institute,| suspect, and somebody must always, Hinxton Hall, | somehow, be thanked." Cambridge, CB10 1SD, UK | --- Umberto Eco ----------------------------------- Email: keller@ebi.ac.uk | Tel. (+44/0)1223 494637 | Macromolecular Structure Database Fax. (+44/0)1223 494468 | http://www2.ebi.ac.uk/msd ========================================================================