https://github.com/607011/getopt-cpp

A sleek and slender C++'ish alternative to getopt and getopt_long
https://github.com/607011/getopt-cpp

command-line cplusplus cplusplus-11 getopt getopt-long parsing

Last synced: 26 days ago
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A sleek and slender C++'ish alternative to getopt and getopt_long

• Host: GitHub
• URL: https://github.com/607011/getopt-cpp
• Owner: 607011
• License: mit
• Created: 2023-05-02T14:06:50.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2024-06-21T07:52:09.000Z (5 months ago)
• Last Synced: 2024-09-30T00:01:42.137Z (about 1 month ago)
• Topics: command-line, cplusplus, cplusplus-11, getopt, getopt-long, parsing
• Language: C++
• Homepage:
• Size: 24.4 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# getopt++

**A sleek and slender C++'ish alternative to getopt and getopt_long**

This library is header-only. Just `#include` [getopt.hpp](https://github.com/607011/getopt-cpp/blob/main/include/getopt.hpp) and you're done.

The `reg()` method registers a handler for a list of command-line switches. If `argparser` finds one of the switches, it calls the handler with the argument, if the switch requires an argument (`argparser::required_argument`), otherwise it calls the handler with an empty string.

If `argparser` finds command-line parameters without a switch, these can be queried as so-called positional arguments. Handlers for positionals are registered with the `pos()` method.

Using `info()` and `help()` you can improve the help output.

## Example

```cpp

#include 

#include 

// this is the getopt++ specific include directive

#include 

int main(int argc, char *argv[])

{

  // variables modified by command-line switches

  unsigned long num_threads = 1;

  int verbosity = 0;

  std::string input_file;

  std::string output_file;

  // definition of command-line switches

  using argparser = argparser::argparser;

  argparser opt(argc, argv);

  opt

    .info("getopt++ demo", argv[0])

    // register command-line switches that execute

    // the built-in help display

    .help({"-?", "--help"}, "Display this help")

    // register command-line switches that modify

    // a variable according to the argument given

    .reg({"-t", "--threads"},

         "NUM_THREADS", // will be used in help to illustrate the argument

         argparser::required_argument,

         "Set number of threads", // will be displayed in help

         [&num_threads](std::string const &arg)

         {

            num_threads = std::stoul(arg);

        })

    // register command-line switch that doesn't

    // expect an argument, i.e. to increase the

    // level of verbosity

    .reg({"-v"},

         argparser::no_argument,

         "Increase verbosity of output",

         [&verbosity](std::string const &)

         {

            ++verbosity;

         })

    // register positional arguments

    .pos("INPUT_FILE", // will be used in help to illustrate the argument

         "Set file to read", // will be displayed in help

         [&input_file](std::string const &arg)

         { input_file = arg; })

    .pos("OUTPUT_FILE", // will be used in help to illustrate the argument

         "Set file to write", // will be displayed in help

         [&output_file](std::string const &arg)

         { output_file = arg; });

  try

  {

    // parse command-line and execute handlers accordingly

    opt();

  }

  // user requested help, help was shown, 

  // everything's fine, so exit smoothly

  catch (::argparser::help_requested_exception const &)

  {

    return EXIT_SUCCESS;

  }

  // handle cases where a required argument was not given

  catch (::argparser::argument_required_exception const &e)

  {

    std::cerr << "\u001b[31;1mERROR: " << e.what() << "\u001b[0m\n";

    return EXIT_FAILURE;

  }

  // handle cases where an unknown switch was given

  catch (::argparser::unknown_option_exception const &e)

  {

    std::cerr << "\u001b[31;1mERROR: " << e.what() << "\u001b[0m\n";

    opt.display_help(); 

    return EXIT_FAILURE;

  }

  // handle all other exceptions

  catch (std::exception const &e)

  {

    std::cerr << "\u001b[31;1mERROR: " << e.what() << "\u001b[0m\n";

    return EXIT_FAILURE;

  }

  return EXIT_SUCCESS;

}

```

## More examples

  - [txtz](https://github.com/607011/txtz/blob/main/src/mapbuilder.cpp)

  - [sudoku++](https://github.com/607011/sudokuplusplus/blob/main/src/main.cpp)

  - [hibpdl++](https://github.com/607011/hibpdl/blob/main/src/main.cpp)

  - [dirb++](https://github.com/607011/dirbplusplus/blob/main/src/main.cpp)