dict.swift

#!/usr/bin/swift

import AppKit
import CoreServices

let args = CommandLine.arguments[1...]
let words = args.filter { !$0.hasPrefix("-") }

guard !words.isEmpty else {
    print("Usage: \(URL(string: #file)!.lastPathComponent) [-o] <word1> [word2 [word3 [...]]]")
    exit(EX_USAGE)
}

if args.contains("-o") {
    print("Opening Dictionary.app…")
    NSWorkspace.shared.open(URL(string: "dict://\(words[0])")!)
    exit(EX_OK)
}

enum DefinitionResult: CustomStringConvertible {
    case success(word: String, definition: String)
    case notFound(word: String)
    
    var isSuccess: Bool {
        if case .success = self {
            return true
        } else {
            return false
        }
    }
    
    var description: String {
        switch self {
        case .success(word: _, definition: let definition):
            return definition
        case .notFound(word: let word):
            return "\(word): not found"
        }
    }
}

let definitions = words.map { word -> DefinitionResult in
    if let result = DCSCopyTextDefinition(
        /* dictionary */ nil,
        /* word */ word as CFString,
        /* range */ CFRangeMake(0, word.utf16.count)
    )?.takeRetainedValue() as String? {
        return .success(word: word, definition: result)
    } else {
        return .notFound(word: word)
    }
}

print(definitions.map(String.init(describing:)).joined(separator: "\n\n"))

if definitions.contains(where: \.isSuccess) {
    exit(EX_OK)
} else {
    exit(EX_UNAVAILABLE)
}