flag is a tool: parse command-line parameters.
Provide two program language: Swift and C++.
In Swift
let host = flag.String(name: "h", defValue: "localhost", usage: "Server host string")
let port = flag.Integer(name: "p", defValue: 1234, usage: "Network port(TCP)")
let race = flag.Float(name: "race", defValue: 0, usage: "Test the float value")
let logg = flag.Bool(name: "log", defValue: false, usage: "show the log")
flag.parse()
print("connect to \(host.pointee):\(port.pointee) with race \(race.pointee). Show log?:\(logg.pointee)")Assume we input:
./flag-swift -h=www.github.com -p 9009 -race=32.9744445567 -log
And then we get the output:
connect to www.github.com:9009 with race 32.9744445567. Show log?:true
In C++
Flag::InitialCommandLine(argc, argv);
auto host = Flag::String("h", "localhost", "Server host string");
auto port = Flag::Integer("p", 1234, "Network port(TCP)");
auto race = Flag::Float("race", 0, "Test the float value");
auto logg = Flag::Bool("log", false, "show the log");
Flag::Parse();
cout << "connect to " << *host << ":" << *port << " with race " << *race << ". Show log?:" << *logg << endl;Assume we input:
./flag-swift -h=www.github.com -p 9009 -race=32.9744445567 -log
And then we get the output:
connect to www.github.com:9009 with race 32.9744. Show log?:1
The key-value may be -key=value or -key value. Especially for bool value, -key represents true.
Default Key
-help print flag your set help information. For demo's help info is:
Usage of flag-cpp:
-h string
Server host string (default "localhost")
-p int
Network port(TCP) (default 1234)
-race float
Test the float value (default 0.0)
-log
show the log
The MIT LICENSE.