digitalmars.D - Re: getopt upgrade
- Andrej Mitrovic <andrej.mitrovich gmail.com> Jan 03 2014
On 9/3/13, Jacob Carlborg <doob me.com> wrote:Could we get some form of API to set a header and footer that is printed with the help text. Possible idea: bool help; getopt(args, "h|help", &help, doc("Show this message and exit."); getopt.header = "Usage foo [options]\nVersion 0.0.1\n\n"; getopt.footer = "\n\nUse the 'h' flag for help.";
I have a simpler idea, and I'm already working on the following features: // no help string: getopt(args, "foo", &foo); $ app --help I think it would be nice if getopt simply listed all the options here, even if there are no help strings attached and no --help options explicitly defined. // help string is in-between the name and the address, // which is an easy disambiguation for getopt: getopt(args, "foo", "describe foo option", &foo); $ app --help This would print out all the options and their individual help strings (when present). // header and footer is described after an explicit "help" option: getopt(args, "foo", "describe foo option", &foo, "help", "this is the header for --help", "this is the footer for --help"); $ app --help This would print out the header, followed by all the options and their individual help strings, followed by the footer. Additionally, I was thinking that getopt could be smart enough that if you run: $ app --help=foo It would only display the help string for the foo option (if present). Another addition: when parsing the runtime argument for some option fails: bool threads; getopt(args, "threads", "use multithreading", &threads); $ app --threads=1 Currently this prints: ----- std.conv.ConvException std\conv.d(2794): Can't parse string: bool should be case-insensitive 'true' or 'false' ----- But if a help string is present we could append the help string to the exception message: ----- std.conv.ConvException std\conv.d(2794): Can't parse string: bool should be case-insensitive 'true' or 'false' Help string for option 'threads': use multithreading ----- The one special case is when the user actually wants --help to store to a variable, e.g.: getopt(args, "foo", &foo, "help", &help); In that case getopt would simply parse --help as a regular option, rather than attempt to print out the help screen. This avoids any existing code from breaking. Thoughts? Andrei?
Jan 03 2014