Simple and typesafe commandline parsing for C++14.
Simply provide a class with fields that is to be filled by command-line arguments:
struct hello
{
static const char* help()
{
return "Simple program that greets NAME for a total of COUNT times.";
}
int count;
std::string name;
hello() : count(1)
{}
template<class F>
void parse(F f)
{
f(count, "--count", "-C", args::help("Number of greetings."));
f(name, "--name", "-N", args::help("The person to greet."), args::required());
}
void run()
{
for(int i=0;i<count;i++) printf("%s\n", name.c_str());
}
};
int main(int argc, char const *argv[])
{
args::parse<hello>(argc, argv);
}The command then could be run like this:
$ hello --name Paul --count 3
Paul
Paul
Paul
The args library will auto-generate help info:
$ hello --help
Usage: hello [options...]
Simple program that greets NAME for a total of COUNT times.
Options:
-h, --help Show help
--count, -C [integer] Number of greetings.
--name, -N [string] The person to greet.
In addition, nested commands can be created:
struct cli : args::group<cli>
{
static const char* help()
{
return "Command-line interface to manage a database";
}
};
struct initdb : cli::command<initdb>
{
initdb() {}
static const char* help()
{
return "Initialize database";
}
void run()
{
printf("Initialize database\n");
}
};
struct dropdb : cli::command<dropdb>
{
dropdb() {}
static const char* help()
{
return "Delete database";
}
void run()
{
printf("Delete database\n");
}
};
int main(int argc, char const *argv[])
{
args::parse<cli>(argc, argv);
}
So each subcommand can be ran like this:
$ cli initdb
Initialize database
$ cli dropdb
Delete database
In addition help is generated for subcommands as well:
$ cli --help
Usage: cli [options...] [command]
Command-line interface to manage a database
Options:
-h, --help Show help
Commands:
dropdb Delete database
initdb Initialize database
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