Checkmol is a command-line utility program which reads molecular structure files in different formats and analyzes the input molecule for the presence of various functional groups and structural elements. At present, approx. 200 different functional groups are recognized. Output can be either clear text (English or German), a bitstring or its ASCII representation, or a set of special 8-character codes. This output can be easily placed into a database table, permitting the creation of chemical databases with a functional group search option. It was written by Norbert Haider, Department of Pharmaceutical Chemistry (now: Department of Drug and Natural Product Synthesis), University of Vienna, Austria.

The software is available both as source code and as a binary compiled for Linux (x86 architecture). It is entirely written in Pascal and it was compiled with Free Pascal 1.0.11 or Free Pascal 2.4.0 (starting from v0.4c). So to install we first need to get a Pascal compiler, this can be downloaded from Sourceforge.

Full details are here.