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I'm looking for a Swift function like getch() from C to read a single character from terminal input without requiring the user to press the return key. getchar() and readLine() are not sufficient, as they both require return.

There's a getch() function from ncurses which looked promising, but unfortunately seems to require taking over the display of the whole window.

user12638282
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1 Answers1

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After searching for a while online, I landed on the following (partly based on this answer):

import Foundation

extension FileHandle {
    func enableRawMode() -> termios {
        var raw = termios()
        tcgetattr(self.fileDescriptor, &raw)

        let original = raw
        raw.c_lflag &= ~UInt(ECHO | ICANON)
        tcsetattr(self.fileDescriptor, TCSADRAIN, &raw)
        return original
    }

    func restoreRawMode(originalTerm: termios) {
        var term = originalTerm
        tcsetattr(self.fileDescriptor, TCSADRAIN, &term)
    }
}

func getch() -> UInt8 {
    let handle = FileHandle.standardInput
    let term = handle.enableRawMode()
    defer { handle.restoreRawMode(originalTerm: term) }

    var byte: UInt8 = 0
    read(handle.fileDescriptor, &byte, 1)
    return byte
}

fputs("Press any key to continue... ", stdout)
fflush(stdout)

let x = getch()
print()
print("Got character: \(UnicodeScalar(x))")
user12638282
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