Okay, I finally found out the missing part. In case someone else is looking for the same info, here's my finding: There's additional flags that can be used to control this behavior, specifically the command_line_style::style_t::allow_long_disguise is the one that will make single dash options work exactly like double-dash. Here's an example : namespace po = boost::program_options; po::command_line_style::style_t style = po::command_line_style::style_t( po::command_line_style::unix_style | po::command_line_style::case_insensitive | po::command_line_style::allow_long_disguise ); string inputFilename; string statelessTeslaMethodsFilename; string strConfigFile; po::options_description desc2; desc2.add_options() ( "config-file", po::value< std::string >( & strConfigFile )->default_value( "jaja" ) ); po::variables_map vm2; po::store(po::parse_command_line(argc, argv, desc2, style ), vm2); po::notify(vm2); Enjoy, Guy. ________________________________ From: Guy Peled Sent: Thursday, January 05, 2006 9:15 AM To: 'boost-users@lists.boost.org' Subject: RE: [Boost-users] [Boost.Program_options] Is there a way to havealloptions specifiedwith a single dash instead of double? Hmmm...I must be missing something very obvious. Trying your example, I still don't seem to be able to use -config-file, but only --config-file. Here's my code snippet: string strConfigFile; po::options_description desc2; desc2.add_options() ( "config-file", po::value< std::string >( & strConfigFile )->default_value( "jaja" ) ); po::variables_map vm2; po::store(po::parse_command_line(argc, argv, desc2), vm2); po::notify(vm2); And this is accepted fine: --config-file foo While this throws an 'unkown option -c': -config-file foo Any insights into what may be causing such a difference in behaviot? Thanks Guy, ________________________________ From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Alexandre Gacon Sent: Thursday, January 05, 2006 8:46 AM To: boost-users@lists.boost.org Subject: Re: [Boost-users] [Boost.Program_options] Is there a way to havealloptions specifiedwith a single dash instead of double? No, all the args start with a single '-'. For example, with the following code: po::options_description desc; desc.add_options() ( "config-file", po::value< std::string >( & strConfigFile )->default_value( defaultConfigFilePath.native_file_string() ) ); I am able to call my program with a -config-file my_config_file.cfg command line. Alexandre ________________________________ De : boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Guy Peled Envoyé : jeudi 5 janvier 2006 17:21 À : boost-users@lists.boost.org Objet : [Boost-users] [Boost.Program_options] Is there a way to have alloptions specifiedwith a single dash instead of double? I'm interested in switching over the command line processing of an existing tool to use program_options. However, all of the args are of the format '-foo -bar -whatever 1' etc. As far as I can tell from the docs it seems like by default the program_options library assumes args all start with a '--' or have single character short names that start with a single dash. Is there a way to coerce it into the behavior I'm looking for? Thanks for any tips! Guy. _________________________________________________________________ Guy Peled Email gpeled@nvidia.com 3D/Tools Architect 408-486-2505 nVIDIA 2701 San Tomas Expressway www.nvidia.com file:///\\www.nvidia.com Santa Clara, CA 95050 _________________________________________________________________