Termux pkg update error on Android devices

If you have pkg update error on your old installation of Android devices

pkg install termux-tools
termux-change-repo

How to install Swift 5 compiler for Android Termux App

(1) Installation of packages
pkg install clang
pkg install swift


(2) Test Grand Central Dispatch - concurrent queue

Shell script   Select all

cd $HOME cat >$HOME/concurrentqueue.swift <<'HEREEOF' /* # Concurrent Programming with Grand Central Dispatch in Swift 5 */ import Foundation let globalQueue = DispatchQueue.global(qos: .userInitiated) func trace(task: Int) { // Generates a random integer in the [0, task] range print("Task \(task) started") sleep( UInt32.random(in: 0...UInt32(task)) ) print("Task \(task) completed") } print("Concurrent queue, synchronous execution") for i in 1...5 { print("Submitting task \(i)") globalQueue.sync { trace(task: i) } } print("\nConcurrent queue, asynchronous execution") for i in 6...9 { print("Submitting task \(i)") globalQueue.async { trace(task: i) } } sleep(10) print("Program ended") HEREEOF # test swiftc concurrentqueue.swift ./concurrentqueue

(3) Test Grand Central Dispatch - serial queue

Shell script   Select all

cd $HOME cat >$HOME/serialqueue.swift <<'HEREEOF' /* # Concurrent Programming with Grand Central Dispatch in Swift 5 */ import Foundation let serialQueue = DispatchQueue(label: "com.mycompany.demo.serial") func trace(task: Int) { // Generates a random integer in the [0, task] range print("Task \(task) started") sleep( UInt32.random(in: 0...UInt32(task)) ) print("Task \(task) completed") } print("\nSerial queue, synchronous execution") for i in 1...5 { print("Submitting task \(i)") serialQueue.sync { trace(task: i) } } print("\nSerial queue, asynchronous execution") for i in 6...9 { print("Submitting task \(i)") serialQueue.async { trace(task: i) } } sleep(25) print("Program ended") HEREEOF # test swiftc serialqueue.swift ./serialqueue