C++ 简单的命令行参数阅读器
key_zhou
8年前
来自： https://helloacm.com/c-simple-command-line-parameters-reader/
Inthis post, the C# version of Command Line Parameter Reader is given and you should see how easy to manipulate the strings in C#. The C++ version is also very powerful in handling strings using the std library.
C++ Coding Exercise: This is a useful class to handle the command line parameters (as key-value pairs).
/* Author: https://helloacm.com Free to Use, donation is appreciated: https://helloacm.com/out/paypal */ #include <iostream> #include <map> #include <vector> #include <algorithm> using namespace std; class SimpleCommandLineReader { public: SimpleCommandLineReader(int, char**); SimpleCommandLineReader(int, char**, bool); string Get(string); string Get(string, string); private: const char SepChar = '='; vector<string> _args; map<string, string> _dict; bool _caseSensitive = false; void process(void); }; SimpleCommandLineReader::SimpleCommandLineReader(int argc, char** argv): SimpleCommandLineReader(argc, argv, false) { }; SimpleCommandLineReader::SimpleCommandLineReader(int argc, char** argv, bool sensitive){ _caseSensitive = sensitive; for (int i = 0; i < argc; i ++) { string cur(argv[i]); _args.push_back(cur); } process(); }; void SimpleCommandLineReader::process(void) { for (int i = 0; i < _args.size(); i ++) { string cur = _args[i]; string key = ""; string val = ""; for (int j = 0; j < cur.length(); j ++) { if (cur[j] == SepChar) { key = cur.substr(0, j); val = cur.substr(j + 1); break; } } if (!_caseSensitive) { std::transform(key.begin(), key.end(), key.begin(), ::tolower); } _dict[key] = val; } } string SimpleCommandLineReader::Get(string key) { return Get(key, ""); } string SimpleCommandLineReader::Get(string key, string default_value) { if (!_caseSensitive) { std::transform(key.begin(), key.end(), key.begin(), ::tolower); } if (_dict.count(key) > 0) { return _dict[key]; } return default_value; }/* Author: https://helloacm.com Free to Use, donation is appreciated: https://helloacm.com/out/paypal */ #include <iostream> #include <map> #include <vector> #include <algorithm> using namespace std; class SimpleCommandLineReader { public: SimpleCommandLineReader(int, char**); SimpleCommandLineReader(int, char**, bool); string Get(string); string Get(string, string); private: const char SepChar = '='; vector<string> _args; map<string, string> _dict; bool _caseSensitive = false; void process(void); }; SimpleCommandLineReader::SimpleCommandLineReader(int argc, char** argv): SimpleCommandLineReader(argc, argv, false) { }; SimpleCommandLineReader::SimpleCommandLineReader(int argc, char** argv, bool sensitive){ _caseSensitive = sensitive; for (int i = 0; i < argc; i ++) { string cur(argv[i]); _args.push_back(cur); } process(); }; void SimpleCommandLineReader::process(void) { for (int i = 0; i < _args.size(); i ++) { string cur = _args[i]; string key = ""; string val = ""; for (int j = 0; j < cur.length(); j ++) { if (cur[j] == SepChar) { key = cur.substr(0, j); val = cur.substr(j + 1); break; } } if (!_caseSensitive) { std::transform(key.begin(), key.end(), key.begin(), ::tolower); } _dict[key] = val; } } string SimpleCommandLineReader::Get(string key) { return Get(key, ""); } string SimpleCommandLineReader::Get(string key, string default_value) { if (!_caseSensitive) { std::transform(key.begin(), key.end(), key.begin(), ::tolower); } if (_dict.count(key) > 0) { return _dict[key]; } return default_value; }To demonstrate the usage:
int main(int argc, char** argv) { SimpleCommandLineReader param(argc, argv); cout << param.Get("key1") << endl; cout << param.Get("key2", "default_value_key2") << endl; cout << param.Get("key3", "default_value_key3") << endl; return 0; }int main(int argc, char** argv) { SimpleCommandLineReader param(argc, argv); cout << param.Get("key1") << endl; cout << param.Get("key2", "default_value_key2") << endl; cout << param.Get("key3", "default_value_key3") << endl; return 0; }The .h and .cpp C++ code has been maintained at github so feel free to contribute.
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