Implement unwatching a path

Sources/Inotify/Inotify.swift

@@ -21,6 +21,13 @@ public actor Inotify {
 		return wd
 	}
 
+	public func removeWatch(_ wd: Int32) throws {
+		guard inotify_rm_watch(self.fd, wd) == 0 else {
+			throw InotifyError.removeWatchFailed(watchDescriptor: wd, errno: cinotify_get_errno())
+		}
+		watches.removeValue(forKey: wd)
+	}
+
 	deinit {
 		cinotify_deinit(self.fd)
 	}

Sources/Inotify/InotifyError.swift

@@ -3,6 +3,7 @@ import CInotify
 public enum InotifyError: Error, Sendable, CustomStringConvertible {
 	case initFailed(errno: Int32)
 	case addWatchFailed(path: String, errno: Int32)
+	case removeWatchFailed(watchDescriptor: Int32, errno: Int32)
 
 	public var description: String {
 		switch self {
@@ -10,6 +11,8 @@ public enum InotifyError: Error, Sendable, CustomStringConvertible {
 			"inotify_init1 failed: \(readableErrno(code))"
 		case .addWatchFailed(let path, let code):
 			"inotify_add_watch failed for '\(path)': \(readableErrno(code))"
+		case .removeWatchFailed(let wd, let code):
+			"inotify_rm_watch failed for wd \(wd): \(readableErrno(code))"
 		}
 	}
 

Tests/InotifyIntegrationTests/WatchTests.swift

@@ -18,4 +18,19 @@ struct WatchTests {
 			try await watcher.addWatch(path: "/nonexistent-\(UUID())", mask: .allEvents)
 		}
 	}
+
+	@Test func removeWatchSucceeds() async throws {
+		try await withTempDir { dir in
+			let watcher = try Inotify()
+			let wd = try await watcher.addWatch(path: dir, mask: .allEvents)
+			try await watcher.removeWatch(wd)
+		}
+	}
+
+	@Test func removeInvalidWatchThrows() async throws {
+		let watcher = try Inotify()
+		await #expect(throws: InotifyError.self) {
+			try await watcher.removeWatch(9999)
+		}
+	}
 }