feat: add wait option for mouse-position

Sources/SendKeysLib/MousePosition.swift

@@ -1,13 +1,67 @@
 import ArgumentParser
+import Foundation
 
 struct MousePosition: ParsableCommand {
     public static let configuration = CommandConfiguration(
-        abstract: "Prints the current mouse position"
+        abstract: "Prints the current mouse position."
     )
 
+    @Flag(help: "Wait for user input to diplay the mouse position. Useful for capturing multiple mouse positions.")
+    var wait = false
+
     mutating func run() {
+        if wait {
+            listenForInput()
+        } else {
+            printMousePosition()
+        }
+    }
+
+    func printMousePosition() {
         let location = MouseController().getLocation()!
-
         print(String(format: "%.0f,%.0f", location.x, location.y))
     }
+
+    func listenForInput() {
+        fputs("Waiting for user input... Escape or ctrl + d to stop, or any other key to capture mouse position.\n", stderr)
+
+        let stdIn = FileHandle.standardInput
+        let originalTerm = enableRawMode(fileHandle: stdIn)
+
+        var char: UInt8 = 0
+        while read(stdIn.fileDescriptor, &char, 1) == 1 {
+            if char == 4 /* EOF (Ctrl+D) */ || char == 27 /* escape */ {
+                break
+            }
+
+            printMousePosition()
+        }
+
+        restoreRawMode(fileHandle: stdIn, originalTerm: originalTerm)
+    }
+
+    // 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);
+    }
 }