Opag, which stands for Option Parser Generator, is a program to generate C or C++ code which parses command line options. It takes as input a description of the command line options you want your program to support. The output is a C or C++ function which finds these options in an array of strings (typically argv, the second parameter of the main function) and sets variables accordingly. Short (single character) as well as long (GNU style) options are supported.

It is also possible to associate a help string with each option. Opag uses these to create a macro which expands to a string containing a nicely formatted description of the options.

Opag is Free Software, released under the GNU General Public License.

The file INSTALL contains general installation instructions. If you have not yet read it, please do so now.

Opag uses itself to build the files options.c and options.h from options.opag (in the src directory). Therefore, if you want to modify options.opag, you must already have an opag executable. The configure script tries to find such an executable, but you can also specify its location with the option --with-opag. Please type ./configure --help for more information.

The original author of Opag is Martin Dickopp, and the opag home page used to be located at http://www.zero-based.org/software/opag/, but this site is no longer exists.

The Opag source code is now available from https://github.com/mok0/opag.