Swift 3 script for sending files and folders to the trash, using the SwiftShell framework from https://github.com/kareman/SwiftShell .

trash.swift

#!/usr/bin/env swiftshell

/*
* Released under the MIT License (MIT), http://opensource.org/licenses/MIT
*/

import SwiftShell

import Dispatch
import Cocoa

extension Sequence where Iterator.Element: Hashable {
	/// Returns an array containing each element in `self` only once, in the same order. Complexity: O(n)
	func removeDuplicates () -> [Iterator.Element] {
		var alreadyhere = Set<Iterator.Element>(minimumCapacity: underestimatedCount)
		return filter { x in alreadyhere.contains(x) ? false : { alreadyhere.insert(x); return true }() }
	}
}

DispatchQueue.main.async {
	let filesToTrash = main.arguments.removeDuplicates().map(URL.init(fileURLWithPath:))

	NSWorkspace.shared().recycle(filesToTrash) { trashedFiles, error in
		guard let error = error else { exit(0) }

		main.stderror.writeln("Files that could not be trashed:")
		for file in filesToTrash where trashedFiles[file] == nil {
			main.stderror.writeln(file.relativePath)
		}
		main.stderror.writeln()
		exit(error)
	}
}

RunLoop.current.run()

See http://blog.nottoobadsoftware.com/swiftshell/move-files-to-the-trash/ for a brief description of this script.