问题描述
目前我正在尝试从我的 swift 应用程序中的命令行收听用户输入.
Currently I am trying to listen to user input from the command line in my swift application.
我知道 readLine()
方法,但它并不真正适合我的需要.我想监听在命令行上插入的数据.就像用户在终端内按下向上键"一样.
I am aware of the readLine()
method but it does not really fit my needs. I want to listen for data being inserted on the command line. Like when a user is pressing the ‘up key’ inside the terminal.
类似于在 Node.js 中可以完成的事情:
Something like what can be done in Node.js:
stdin.on( 'data', function( key ){
if (key === '\u0003' ) {
process.exit();
} // write the key to stdout all normal like
process.stdout.write( key );
});
我尝试搜索,但在 Swift 中找不到与此等效的内容.我想可能与Inputstream"有关,但也没有找到合适的解决方案.
I tried searching but I couldn’t find an equivalent to this in Swift. I thought maybe something with ‘Inputstream’ but didn’t a find a appropriate solution either.
如果有人能给我一些关于如何在 Swift 中做这样的事情的提示,我将不胜感激.
If someone could give me some hints on how to do something like this in Swift I would highly appreciate it.
推荐答案
通常标准输入会缓冲所有内容,直到输入换行符,这就是为什么典型的标准输入是按行读取的:
Normally standard input buffers everything until a newline is entered, that's why a typical standard input is read by lines:
while let line = readLine() {
print(line)
}
(按CTRL+D发送EOF,即结束输入)
(press CTRL+D to send EOF, that is end the input)
要真正分别读取每个字符,您需要进入原始模式,这意味着使用低级终端功能:
To really read every character separately, you need to enter raw mode and that means use the low level terminal functions:
// see https://stackoverflow.com/a/24335355/669586
func initStruct<S>() -> S {
let struct_pointer = UnsafeMutablePointer<S>.allocate(capacity: 1)
let struct_memory = struct_pointer.pointee
struct_pointer.deallocate()
return struct_memory
}
func enableRawMode(fileHandle: FileHandle) -> termios {
var raw: termios = initStruct()
tcgetattr(fileHandle.fileDescriptor, &raw)
let original = raw
raw.c_lflag &= ~(UInt(ECHO | ICANON))
tcsetattr(fileHandle.fileDescriptor, TCSAFLUSH, &raw);
return original
}
func restoreRawMode(fileHandle: FileHandle, originalTerm: termios) {
var term = originalTerm
tcsetattr(fileHandle.fileDescriptor, TCSAFLUSH, &term);
}
let stdIn = FileHandle.standardInput
let originalTerm = enableRawMode(fileHandle: stdIn)
var char: UInt8 = 0
while read(stdIn.fileDescriptor, &char, 1) == 1 {
if char == 0x04 { // detect EOF (Ctrl+D)
break
}
print(char)
}
// It would be also nice to disable raw input when exiting the app.
restoreRawMode(fileHandle: stdIn, originalTerm: originalTerm)
参考 https://viewsourcecode.org/snaptoken/kilo/02.enteringRawMode.html
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