A header only c++ library for parsing command line arguments and generating usage/help output.
parg
/
examples
/
advanced
/
src
/
main.cc
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103#include "parg.hh"
#include <iostream>
#include <string>
int program_options(OB::Parg& pg);
int program_options(OB::Parg& pg)
{
// set info
pg.name("app").version("0.1.0 (00.00.0000)");
pg.description("a command line app");
pg.usage("[flags] [options] [--] [arguments]");
pg.usage("[-v|--version]");
pg.usage("[-h|--help]");
pg.info("Exit Codes", {"0 -> normal", "1 -> error"});
pg.info("Examples", {
pg.name() + " --help",
pg.name() + " --version",
});
pg.author("name <email>");
// set options
pg.set("help,h", "print the help output");
pg.set("version,v", "print the program version");
pg.set("flag_a,a", "a boolean flag with default value of false");
pg.set("option,o", "20", "int", "an option with a default value of '20'");
pg.set("option_required,r", "", "string", "a required option");
// uncomment to collect positional arguments
// pg.set_pos();
// uncomment to collect piped input
// pg.set_stdin();
int status {pg.parse()};
// uncomment if at least one argument is expected
// if (status > 0 && pg.get_stdin().empty())
// {
// std::cout << pg.print_help() << "\n";
// std::cout << "Error: " << "expected arguments" << "\n";
// return -1;
// }
if (status < 0)
{
// handle parsing error
std::cout << pg.help() << "\n";
std::cout << "Error: " << pg.error() << "\n";
return -1;
}
if (pg.get<bool>("help"))
{
// handle -h and --help
std::cout << pg.help();
return 1;
}
if (pg.get<bool>("version"))
{
// handle -v and --version
std::cout << pg.name() << " v" << pg.version() << "\n";
return 1;
}
return 0;
}
int main(int argc, char *argv[])
{
OB::Parg pg {argc, argv};
int pstatus {program_options(pg)};
if (pstatus > 0)
{
// exit success
return 0;
}
else if (pstatus < 0)
{
// exit error
return 1;
}
// get flag
bool flag_a {pg.get<bool>("flag_a")};
std::cout << "flag_a: " << std::boolalpha << flag_a << "\n";
// get int option
int option {pg.get<int>("option")};
std::cout << "option: " << option << '\n';
// check for required string option
if (pg.find("option_required"))
{
std::string option_required {pg.get("option_required")};
std::cout << "option_required: " << option_required << "\n";
}
else
{
std::cout << pg.help() << "\n";
std::cout << "Error: " << "'option_required' is required" << "\n";
return -1;
}
return 0;
}