Before running your COBOL application through the cobutf8 utility, you must configure the cobutf8.cfg configuration file with a valid mapping, and then set the COBUTF8 environment variable to a valid target locale specified in the mapping.
Once you have set these two pre-requisites, you can run your application from the command line using the following syntax:
cobutf8 <command-line>
where command line is your target program and any command-line arguments it requires. For example, the following command runs the my-shiftjis.int program through cobutf8:
cobutf8 cobrun my-shiftjis.int