boost::program_options demo

Posted on June 9, 2018 by admin

A Simple Demo

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//
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// Created by Water on 2018/6/9.
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```
//
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#include <iostream>
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#include <string>
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#include <boost/program_options.hpp>
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namespace  bpo = boost::program_options;

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int main(int argc, char const *argv[])
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{
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    bpo::options_description opts("all options");

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    bpo::variables_map vm;
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    opts.add_options()
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            ("filename", bpo::value<std::string>(), "the file name which want to be found")

            ("help", "this is a program to find a specified file");

```
 
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    try{
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        bpo::store(bpo::parse_command_line(argc, argv, opts), vm);

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    }
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    catch(...){
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        std::cout << "undefined option！\n";

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        return 0;
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    }
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    if(vm.count("help") ){
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        std::cout << opts << std::endl;
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    }
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    if(vm.count("filename") ){
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        std::cout << "find " << vm["filename"].as<std::string>() << std::endl;

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    }
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    if(vm.empty() ){
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        std::cout << "no options found \n";

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    }
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    return 0;
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}
```

Test

How to Set Default Value

```
//
```
```
// Created by Water on 2018/6/9.
```
```
//
```
```
 
```
```
#include <iostream>
```
```
#include <vector>
```
```
#include <string>
```
```
#include <boost/program_options.hpp>
```
```
namespace bpo = boost::program_options;
```
```
 
```
```
int main(int argc, char const *argv[])
```
```
{
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    std::vector<std::string> v_para;
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    std::string port;
```
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    int baud = 0;
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    int timeout = 0;
```

    bpo::options_description opt("all options");

```
 
```
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    opt.add_options()
```

            ("v_para,v", bpo::value<std::vector<std::string> >()->multitoken(), "Serial v_para")

            ("port,p", bpo::value<std::string>(&port)->default_value("COM1"), "Serial Port")

            ("baud,b", bpo::value<int>(&baud)->default_value(115200), "Serial Baud")

            ("timeout,t", bpo::value<int>(&timeout)->default_value(5000), "Timeout")

            ("help", "a demo ( default value )");

```
 
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```
    bpo::variables_map vm;
```
```
 
```
```
    try{
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        bpo::store(parse_command_line(argc, argv, opt), vm);

```
    }
```
```
    catch(...){
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        std::cout << "undefined option！\n";

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        return 0;
```
```
    }
```
```
 
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    bpo::notify(vm);
```
```
 
```
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    if(vm.count("help") ){
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        std::cout << opt << std::endl;
```
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        return 0;
```
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    }
```
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    if(vm.count("v_para") ){
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```
        std::cout << "v_para：";
```

        for(auto& str : vm["v_para"].as<std::vector<std::string> >() )

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            std::cout << str << " ";
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        std::cout << std::endl;
```
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    }
```

    std::cout << "port:" << port << std::endl;

    std::cout << "baud:" << baud << std::endl;

    std::cout << "timeout:" << timeout << std::endl;

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    return 0;
```
```
}
```

Test