libcargs - command line argument library for C/C++

This is a lighweight C command line argument library. It is currently compiled and tested under Windows, MacOS and Linux.

Features

Please have a look at the reference for detailed information. Some features this library includes:

• cross-platform on windows, linux and macOS
• simple interface - just one header
• one simple loop - to iterate over the arguments
• automatic help output - showing all options available
• long and short options - giving users alternatives
• option values - for options which are more than just flags

Building

Building, embedding and testing instructions are available in the documentation (it's very easy).

Docs

All the documentation is available in the the github page of this repository.

Example

#include <cargs.h>
#include <stdbool.h>
#include <stdlib.h>

/**
* This is the main configuration of all options available.
*/
static struct cag_option options[] = {
 {.identifier = 's',
  .access_letters = "s",
  .access_name = NULL,
  .value_name = NULL,
  .description = "Simple flag"},

 {.identifier = 'm',
   .access_letters = "mMoO",
   .access_name = NULL,
   .value_name = NULL,
   .description = "Multiple access letters"},

 {.identifier = 'l',
   .access_letters = NULL,
   .access_name = "long",
   .value_name = NULL,
   .description = "Long parameter name"},

 {.identifier = 'k',
   .access_letters = "k",
   .access_name = "key",
   .value_name = "VALUE",
   .description = "Parameter value"},

 {.identifier = 'h',
   .access_letters = "h",
   .access_name = "help",
   .description = "Shows the command help"}};

/**
* This is a custom project configuration structure where you can store the
* parsed information.
*/
struct demo_configuration
{
 bool simple_flag;
 bool multiple_flag;
 bool long_flag;
 const char *key;
};

int main(int argc, char *argv[])
{
 char identifier;
 const char *value;
 cag_option_context context;
 struct demo_configuration config = {false, false, false, NULL};
 int param_index;

 /**
  * Now we just prepare the context and iterate over all options. Simple!
  */
 cag_option_prepare(&context, options, CAG_ARRAY_SIZE(options), argc, argv);
 while (cag_option_fetch(&context)) {
   identifier = cag_option_get(&context);
   switch (identifier) {
   case 's':
     config.simple_flag = true;
     break;
   case 'm':
     config.multiple_flag = true;
     break;
   case 'l':
     config.long_flag = true;
     break;
   case 'k':
     value = cag_option_get_value(&context);
     config.key = value;
     break;
   case 'h':
     printf("Usage: cargsdemo [OPTION]...\n");
     printf("Demonstrates the cargs library.\n\n");
     cag_option_print(options, CAG_ARRAY_SIZE(options), stdout);
     printf("\nNote that all formatting is done by cargs.\n");
     return EXIT_SUCCESS;
   }
 }

 printf("simple_flag: %i, multiple_flag: %i, long_flag: %i, key: %s\n",
   config.simple_flag, config.multiple_flag, config.long_flag,
   config.key ? config.key : "-");
 
 for (param_index = context.index; param_index < argc; ++param_index) {
   printf("additional parameter: %s\n", argv[param_index]);
 }

 return EXIT_SUCCESS;
}

Example output

foo@bar:~$ ./cargsdemo 
simple_flag: 0, multiple_flag: 0, long_flag: 0, key: -

foo@bar:~$ ./cargsdemo -k=test -sm --long
simple_flag: 1, multiple_flag: 1, long_flag: 1, key: test

foo@bar:~$ ./cargsdemo --help
Usage: cargsdemo [OPTION]...
Demonstrates the cargs library.

  -s                   Simple flag
  -m, -M, -o, -O       Multiple access letters
  --long               Long parameter name
  -k, --key=VALUE      Parameter value
  -h, --help           Shows the command help

Note that all formatting is done by cargs.

foo@bar:~$ ./cargsdemo also -k=test some -sm additional --long parameters
simple_flag: 1, multiple_flag: 1, long_flag: 1, key: test
additional parameter: also
additional parameter: some
additional parameter: additional
additional parameter: parameters