Hi All, I want to be able to do the following using the Boost::program_options library. 1) Parse a set of command line options in a standard way (I know how to achieve this). 2) Have an command line option which is "get other command line options from a config file defined as the argument to this option. The example multiple_sources is very close to the sort of thing I want, however in that example the config file is hard coded. I want the user to interactively set the config file at runtime. If I try simply putting the following lines in the set of if statements my program crashes (I know this is still hard coding the cfg file, but it was a first attempt before I made it more general), if ((vm.count("input-file")) { ifstream ifs("multiple_sources.cfg"); store(parse_config_file(ifs, config_file_options), vm); notify(vm); } Any help would be much appreciated, Adam