Sleep the Main Thread

From Rosetta Code

Write a program that does the following in this order:

• Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
• Print "Sleeping..."
• Sleep the main thread for the given amount of time.
• Print "Awake!"
• End.

[edit] Ada

The Ada delay statement takes an argument of type Duration, which is a real number counting the number of seconds to delay. Thus, 2.0 will delay 2.0 seconds, while 0.001 will delay 0.001 seconds.

with Ada.Text_Io; use Ada.Text_Io;
with Ada.Float_Text_Io; use Ada.Float_Text_Io;
 
procedure Sleep is
   In_Val : Float;
begin
   Get(In_Val);
   Put_Line("Sleeping...");
   delay Duration(In_Val);
   Put_Line("Awake!");
end Sleep;

[edit] BASIC

Works with: QuickBasic version 4.5

INPUT sec 'the SLEEP command takes seconds
PRINT "Sleeping..."
SLEEP sec
PRINT "Awake!"

"SLEEP" with no argument will sleep until a button is pressed on the keyboard (including modifier keys such as shift or control). Also, pressing a key while SLEEP is waiting for a specific amount of time (as above) will end the SLEEP.

[edit] C++

#include <unistd.h>
#include <iostream>
 
using namespace std;
 
int main(int argc, char* argv[])
{
    useconds_t microseconds;
    cin >> microseconds;
    cout << "Sleeping..." << endl;
    usleep(microseconds);
    cout << "Awake!" << endl;
    return 0;
}

[edit] Forth

: sleep ( ms -- )
  ." Sleeping..."
  ms
  ." awake." cr ;

[edit] Haskell

import Control.Concurrent

main = do seconds <- readLn
          putStrLn "Sleeping..."
          threadDelay $ round $ seconds * 1000000
          putStrLn "Awake!"

[edit] Java

import java.util.Scanner;
 
public class Sleep{
	public static void main(String[] args) throws InterruptedException{
		Scanner input = new Scanner(System.in);
		int ms = input.nextInt(); //Java's sleep method accepts milliseconds
		System.out.println("Sleeping...");
		Thread.sleep(ms);
		System.out.println("Awake!");
	}
}

[edit] OCaml

#load "unix.cma";;
let seconds = read_int ();;
print_endline "Sleeping...";;
Unix.sleep seconds;; (* number is integer in seconds *)
print_endline "Awake!";;

[edit] Perl

seconds:

$seconds = <>;
print "Sleeping...\n";
sleep $seconds; # number is in seconds
print "Awake!\n";

microseconds and nanoseconds using the Time::HiRes module:

use Time::HiRes qw( usleep nanosleep );
 
$microseconds = <>;
print "Sleeping...\n";
usleep $microseconds;
print "Awake!\n";
 
$nanoseconds = <>;
print "Sleeping...\n";
nanosleep $nanoseconds;
print "Awake!\n";

[edit] Python

import time
 
seconds = float(raw_input())
print "Sleeping..."
time.sleep(seconds) # number is in seconds ... but accepts fractions
# Minimum resolution is system dependent.
print "Awake!"

[edit] Tcl

set seconds [gets stdin]
puts Sleeping...
after [expr $seconds*1000]
puts Awake!

[edit] Toka

This makes use of the sleep() function from libc which suspends execution for a specified number of seconds.

 1 import sleep as sleep()
 [ ." Sleeping...\n" sleep() drop ." Awake!\n" bye ] is sleep
 
 45 sleep