`chem' is a `roff' language to generate chemical structure diagrams. `@g@chem' is a `groff' preprocessor that produces output suitable for the `@g@pic' preprocessor. The original version of `chem' is an `awk' script written by Brian Kernighan . The source files of the `awk' version of `chem' are available at . This project is a rewrite of `chem' in Perl for the GNU `roff' project `groff'. It was written under Perl v5.8.8, but at least Perl v5.6 is needed to run the Perl version of `chem'. In comparison to the original `awk' version of `chem', the Perl version does the following changements: - the options -h, --help, -v, --version to output usage and version information are added. - remove some functions `inline', `shiftfields', and `set' and some variables that are used only once. The subdirectory `examples/' contains example files for chem. They are written in the `chem' language. The file names end with .chem. ####### License Copyright (C) 2006-2014 Free Software Foundation, Inc. Written by Bernd Warken . This file is part of `chem', which is part of `groff'. `groff' is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (GPL) vbersion 2 as published by the Free Software Foundation. `groff' is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. The GPL2 license text is available in the internet at . ####### Emacs settings Local Variables: mode: text End: