Boost program_options library, parse command line parameters, read configuration files

I. Command Line Parsing

Sample Code for parsing command line parameters in tprogram_options:

 

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1. # Include <iostream>
2. Using namespace STD;
4. # Include <boost/program_options.hpp>
5. Namespace po = boost: program_options;
7. Int main (INT argc, char * argv [])
8. {
9. // Int level;
10. Po: options_description DESC ("allowed options ");
11. Desc. add_options ()
12. ("Help", "produce help message ")
13. // ("Help, H", "produce help message ")
14. ("Compression", Po: value <int> (), "set compression level ");
15. // ("Compression", Po: value <int> (& level)-> default_value (1), "set compression level ");
17. Po: variables_map VM;
18. Po: store (PO: parse_command_line (argc, argv, DESC), Vm );
19. Po: Notify (VM );
21. If (VM. Count ("help "))
22. {
23. Cout <DESC <Endl;
24. Return 1;
25. }
27. If (VM. Count ("compression "))
28. {
29. Cout <"Compression level was set to" <VM ["compression"]. As <int> () <"." <Endl;
30. // Cout <"Compression level:" <level <Endl;
31. }
32. Else
33. {
34. Cout <"Compression level was not set." <Endl;
35. }
37. Return 0;
38. }

 

Running result:

 

Input parameter: -- Help

 

Input parameter: -- compression 10

 

2. Read configuration files (for Linux and Windows)

Code 2.1

 

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1. # Include <fstream>
2. # Include <map>
3. Using namespace STD;
5. # Include <boost/program_options.hpp>
6. Using namespace boost;
7. Namespace po = boost: program_options;
9. # Ifdef Win32
10. # Include "C: \ Users \ gwy8868 \ Desktop \ fast_dr302 \ fast_dr302 \ Global \ xtokens. H"
11. # Else
12. # Include "/opt/guowenyan/fast_dr302/global/xtokens. H"
13. # Endif
16. STD: pair <STD: String, STD: String> at_option_parser (STD: String const & S)
17. {
18. If ('@' = s [0])
19. {
20. Return make_pair (STD: string ("Config"), S. substr (1 ));
21. }
22. Else
23. {
24. Return STD: pair <STD: String, STD: String> ();
25. }
26. }
28. Int main (INT argc, char * argv [])
29. {
30. //
31. String host_ip;
32. Short host_port;
34. String server_ip;
35. Short server_port;
37. //
38. Po: options_description hostoptions ("host options ");
39. Hostoptions. add_options ()
40. ("Host_ip, H", Po: value <string> (& host_ip), "set db_host ")
41. ("Host_port, P", Po: value <short> (& host_port)-> default_value (3306), "set db_port ");
43. Po: options_description General ("general options ");
44. General. add_options ()
45. ("Help, H", "produce help message ")
46. ("Server_ip, s", Po: value <string> (& server_ip), "set the http_server's IP. e.g. '2017. 106.0.20 '")
47. ("Server_port, P", Po: value <short> (& server_port)-> default_value (80), "set the http_server's port. Default: 80 ");
49. String config_file;
50. Po: options_description config ("Config options ");
51. Config. add_options ()
52. ("Config", Po: value <string> (& config_file)-> default_value ("config. conf "),
53. "Set config file, specified with '@ name' too ");
55. Po: options_description all ("all options ");
56. All. Add (hostoptions). Add (general). Add (config );
58. Po: variables_map VM;
59. Po: store (PO: command_line_parser (argc, argv). Options (all). extra_parser (: at_option_parser). Run (), Vm );
61. If (VM. Count ("help "))
62. {
63. Cout
64. Cout <general <Endl;
65. Cout <config <Endl;
66. Return false;
67. }
69. If (VM. Count ("Config "))
70. {
71. String conf_name = VM ["Config"]. As <string> ();
72. Ifstream ifs_config (conf_name.c_str ());
74. If (! Ifs_config)
75. {
76. Cerr <"cocould not open the configure file" <Endl;
77. Return false;
78. }
80. Stringstream ss_config;
81. Ss_config <ifs_config.rdbuf ();
83. Global: strings_t ARGs;
84. Global: separate_tokens (ss_config.str (), argS, "\ r \ n ");
85. Po: store (PO: command_line_parser (ARGs). Options (all). Run (), Vm );
86. }
87. Po: Notify (VM );
90. //
91. Cout <"host_ip:"
92. Cout <"host_port:"
94. Cout <"server_ip:" <server_ip <Endl;
95. Cout <"server_port:" <server_port <Endl;
97. Return 0;
98. }

2.2 configuration file

 

Config. conf:

Config2.conf:

2.3 output results