How to run code out of a string at runtime?

Asked Jul 10 '17 at 21:38

Active Jul 10 '17 at 21:47

Viewed 78 times

First of all, I know that Apple rejects apps that include something like that. It's just for the personal purpose.

I tried the following example:

import Foundation

var instructions: String = "let str = \"Hello\"\nprint(\"\\(str) world\")\n"
let process: Process = Process()

process.launchPath = "/usr/bin/swift"

let inpipe: Pipe = Pipe()
let outpipe: Pipe = Pipe()

inpipe.fileHandleForWriting.write(instructions.data(using: String.Encoding.utf8, allowLossyConversion: true)!)

process.standardInput = inpipe
process.standardOutput = outpipe
process.launch()
process.waitUntilExit() // never ends
process.standardInput = Pipe()

let data = outpipe.fileHandleForReading.readDataToEndOfFile()
let output = String(data: data, encoding: String.Encoding.utf8)

I run the program on a Mac. The program never ends. I don't know where the error could be.

edited Jul 10 '17 at 21:47

asked Jul 10 '17 at 21:38

Rainer Niemann

Have you tried debugging? E.g. setting a breakpoint and stepping through the code – Simon Jul 10 '17 at 21:55
@Rainer what do you want to achieve with process? – Vikram Sinha Nov 17 '17 at 11:11
@vikramsingh I want to develop a program that expands itself. I could write a own interpreter, of course, but this way would be faster and more efficient. – Rainer Niemann Nov 17 '17 at 14:05

How to run code out of a string at runtime?

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