1 // Copyright Vladimir Prus 2002-2004.
2 // Distributed under the Boost Software License, Version 1.0.
3 // (See accompanying file LICENSE_1_0.txt
4 // or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6 /** This example shows how to handle response file.
7
8 For a test, build and run:
9 response_file -I foo @response_file.rsp
10
11 The expected output is:
12 Include paths: foo bar biz
13
14 Thanks to Hartmut Kaiser who raised the issue of response files
15 and discussed the possible approach.
16 */
17
18
19 #include <boost/program_options/options_description.hpp>
20 #include <boost/program_options/parsers.hpp>
21 #include <boost/program_options/variables_map.hpp>
22 #include <boost/tokenizer.hpp>
23 #include <boost/token_functions.hpp>
24 using namespace boost;
25 using namespace boost::program_options;
26
27 #include <iostream>
28 #include <fstream>
29 using namespace std;
30
31 // Additional command line parser which interprets '@something' as a
32 // option "config-file" with the value "something"
at_option_parser(string const & s)33 pair<string, string> at_option_parser(string const&s)
34 {
35 if ('@' == s[0])
36 return std::make_pair(string("response-file"), s.substr(1));
37 else
38 return pair<string, string>();
39 }
40
main(int ac,char * av[])41 int main(int ac, char* av[])
42 {
43 try {
44 options_description desc("Allowed options");
45 desc.add_options()
46 ("help", "produce a help message")
47 ("include-path,I", value< vector<string> >()->composing(),
48 "include path")
49 ("magic", value<int>(), "magic value")
50 ("response-file", value<string>(),
51 "can be specified with '@name', too")
52 ;
53
54 variables_map vm;
55 store(command_line_parser(ac, av).options(desc)
56 .extra_parser(at_option_parser).run(), vm);
57
58 if (vm.count("help")) {
59 cout << desc;
60 }
61 if (vm.count("response-file")) {
62 // Load the file and tokenize it
63 ifstream ifs(vm["response-file"].as<string>().c_str());
64 if (!ifs) {
65 cout << "Could not open the response file\n";
66 return 1;
67 }
68 // Read the whole file into a string
69 stringstream ss;
70 ss << ifs.rdbuf();
71 // Split the file content
72 char_separator<char> sep(" \n\r");
73 string sstr = ss.str();
74 tokenizer<char_separator<char> > tok(sstr, sep);
75 vector<string> args;
76 copy(tok.begin(), tok.end(), back_inserter(args));
77 // Parse the file and store the options
78 store(command_line_parser(args).options(desc).run(), vm);
79 }
80
81 if (vm.count("include-path")) {
82 const vector<string>& s = vm["include-path"].as<vector< string> >();
83 cout << "Include paths: ";
84 copy(s.begin(), s.end(), ostream_iterator<string>(cout, " "));
85 cout << "\n";
86 }
87 if (vm.count("magic")) {
88 cout << "Magic value: " << vm["magic"].as<int>() << "\n";
89 }
90 }
91 catch (std::exception& e) {
92 cout << e.what() << "\n";
93 }
94 }
95