Impatiently wait for input

Question

Your task today is to implement a time limit for getting input, a task I've found rather annoying to achieve in most languages.

You will create a program function which prompts the user for input. Immediatly after the user supplies input, print the message input received and end execution/return. However, if the user waits for more than 10 seconds to provide input, output the message no input received and end execution/return.

Input must be from stdin (the console) or equivalent, not function or program arguments, however output can be either to stdout, your function's return value, or any other accepted output method.

You may ask for any amount of input, it can be a single character, a line, a word, or whatever method is shortest in your language as long as it waits for at least one character.

You must output as soon as the input is received, not after the 10 seconds have passed.

After 10 seconds have passed, you must end, you cannot continue waiting for input after no input received has been printed.

You may assume that input is not passed in the time between 10 seconds elapsing and text being printed to the screen, as this is an extremely small window. You may also assume that your language's builtin equivalent of sleep is consistently, absolutely perfect.

This is code-golf, fewest bytes wins!

Answer 1

bash, 38 bytes

read -t10||a=no;echo $a input received

This uses the -t (timeout) option to bash's read, which causes it to fail and return a nonzero exit code if no input is given in the specified number of seconds.

Answer 2

Haskell, 97 89 bytes

import System.Timeout
timeout(10^7)getChar>>=putStr.(++"input received").maybe"no "mempty

If timeout times out it returns Nothing and Just Char (Char, because we're using getChar) otherwise. This return value is converted to "no " or "" by function maybe "no " mempty. Append "input received" and print.

Edit: @BMO suggested maybe and saved some bytes.

Answer 3

POSIX C99, 71 63 bytes

main(){puts("no input received"+3*poll((int[]){0,1},1,10000));}

Ungolfed:

#include <unistd.h>
#include <poll.h>
#include <stdio.h>
int main()
{
  struct pollfd pfd; 
  pfd.fd = STDIN_FILENO; 
  pfd.events = POLLIN;  
  puts("no input received"+3*poll(&pfd,1,10000));
}

Since poll will return 1 in case of success, we multiply the result by 3 and shift the string accordingly. Then, we use the fact that struct pollfd has the following layout:

     struct pollfd {
     int    fd;       /* file descriptor */
     short  events;   /* events to look for */
     short  revents;  /* events returned */
 };

and that STDIN_FILENO is 0, POLLIN is 1 to replace pfd with int pfd[] = {0,1}, which we finally make a compound litteral (as allowed by C99).

Answer 4

Applescript, 113

Applescript doesn't really do reading from STDIN. Hopefully a display dialog is acceptable here:

({"","no "}'s item((display dialog""default answer""giving up after 10)'s gave up as integer+1))&"input received"

Answer 5

APL (Dyalog), 41 40 bytes

'no input received'↓⍨{3*⍨⎕RTL←10::0⋄3⊣⍞}

This is an anonymous tacit function which needs a dummy argument to run.

'no input received' the full string

↓⍨ drop as many characters from the front of that as the number returned by the

{ anonymous explicit function (⍵ denotes the argument)

 ⎕RTL←10 set Response Time Limit to ten seconds

 3*⍨ raise that number (ten) to the power of three (a thousand means "all")

 :: upon those exceptions (all),

  0 return 0

 ⋄ try:

  ⍞ get input

  3⊣ discard that and instead return 3

} end of function (note that the argument ⍵ was never mentioned)

Answer 6

Perl, 74 67 bytes

$m="input received";$SIG{ALRM}=sub{die"no $m\n"};alarm 10;<>;say$m

Old Version

$m="input received";$SIG{ALRM}=sub{die "no $m\n"};alarm 10;<stdin>;say $m;

(Run via perl -M5.10.1 ...)

Answer 7

Perl 6,  72  66 bytes

my $s='input received';Promise.in(10).then:{say "no $s";exit};get;say $s

Try it with no input
Try it with input

my$s='input received';start {sleep 10;say "no $s";exit};get;say $s

Try it with no input
Try it with input

my $s = 'input received'; # base message

start {         # create a Promise with a code block
                # that is run in parallel
  sleep 10;     # delay for 10 seconds
  say "no $s";  # say ｢no input received｣
  exit          # exit from the process
}

get;            # get a line from the input
say $s          # say ｢input received｣

Answer 8

C#, 180 171 148 131 bytes

()=>{var t=new System.Threading.Thread(()=>{System.Console.ReadKey();});t.Start();return(t.Join(10000)?"":"no ")+"input recieved";}

Saved 17 bytes thanks to @VisualMelon.

Full/Formatted version:

class P
{
    static void Main()
    {
        System.Func<string> f = () =>
        {
            var t = new System.Threading.Thread(() =>
            {
                System.Console.ReadKey();
            });
            t.Start();

            return (t.Join(10000) ? "" : "no ") + "input recieved";
        };

        System.Console.WriteLine(f());
        System.Console.ReadLine();
    }
}

Answer 9

TI-BASIC, 84 77 bytes

-7 thanks to @kamoroso94

:startTmr→T         //Start Timer, 5 bytes
:Repeat checkTmr(T)=10 or abs(int(.1K)-8)≤1 and 1≥abs(3-10fPart(.1K  //Loop until the timer is 10 seconds or a number key is pressed, 32 bytes
:getKey→K           //get key code, 4 bytes
:End                //end loop, 2 bytes
:"NO INPUT RECEIVED //Push string "NO INPUT RECEIVED" to Ans, 18 bytes
:If K               //If input was received, 3 bytes
:Disp sub(Ans,3,15  //Diplay "INPUT RECEIVED", 9 bytes
:If not(K           //If no input, 3 bytes
:Ans                //Display "NO INPUT RECEIVED", 1 byte

Waits until a number is pressed.

I am trying to figure out how to golf the sequence {72,73,74,82,83,84,92,93,94}. It is taking up a lot of space.

Answer 10

NodeJS, 105 103 101 bytes

-2 bytes thanks to @apsillers
-2 bytes by moving console.log() into exit()

with(process)stdin.on('data',r=x=>exit(console.log((x?'':'no ')+'input received'))),setTimeout(r,1e4)

Run by saving to a file and running it with node or run it straight from the command line by doing node -e "<code>"

Answer 11

Go, 149 bytes

package main
import(
."fmt"
."time"
."os"
)
func main(){
o:="input received"
go func(){Sleep(1e10)
Print("no "+o)
Exit(0)}()
i:=""
Scan(&i)
Print(o)}

Answer 12

AHK, 67 65 bytes

^{2 bytes saved by Blauhirn}

InputBox,o,,,,,,,,,10
s:=ErrorLevel?"no ":
Send %s%input received

AHK has a built-in timeout for input boxes.
I tried to get clever and use !o instead of ErrorLevel but that fails if the user inputs a falsey value.
Almost half of the answer is just the command names and fixed text.

Answer 13

JavaScript (ES6) + HTML, 86 84 82 79+11 = 97 95 93 90 bytes

setTimeout(oninput=_=>i.remove(alert(`${i.value?"":"no "}input received`)),1e4)

<input id=i

• 2 bytes saved thanks to apsillers pointing out that I'm dumb!

---

Try it

Requires a closing > on the input in order to work in a Snippet.

setTimeout(oninput=_=>i.remove(alert(`${i.value?"":"no "}input received`)),1e4)

<input id=i>

Answer 14

Python 3, 158 bytes

import os,threading as t,time
def k(t=10):time.sleep(t);print("No input received"[(10-t)//3:]);os.kill(os.getpid(),t)
t.Thread(None,k).start()
if input():k(0)

Answer 15

VB.Net - 174 bytes

Module M
Sub Main()
Dim t=New Threading.Thread(Sub()Console.Read()):t.Start():Console.WriteLine(If(t.Join(10000),"","no ") & "input received"):End
End Sub
End Module

COBOL version coming tomorrow ;-)

Answer 16

Python3, 100 89 83 71 bytes

import pty
print("no input received"[3*any(pty.select([0],[],[],10)):])

First try at golfing.

-4 for any(), -7 for slicing, thanks @user2357112!

-6, get select() from pty instead of select.

Answer 17

PowerShell, 110 bytes

$s1=date;while(![console]::KeyAvailable-and($i=((date)-$s1).seconds-lt10)){}
"{0}input received"-f(,'no ')[$i]

Answer 18

Scratch 2/3.x, 41 points (Explanation)

1: When GF clicked

1: ask [] and wait

1 + 14 chars: say [input received]

1: stop [all v] (note: since "all" was its default setting I counted the block as 1)

1 + 2 digits: wait (10) seconds

1 + 17 chars: say [no input received]

1: stop [all v]

Answer 19

Scratch 3.0 (scratchblocks3 syntax), 129 bytes/40 points

Beats @Syntax Error's answer by 1 point, but loses to it by 8 bytes.

define
broadcast[w v
ask[]and wait
say[input received
stop[all v
when I receive[w v
wait(10)secs
say[no input received
stop[all v

Ungolfed:

define // custom blocks (functions) do not need names. functions are shorter than programs when counting bytes, because programs that run require "when gf clicked"
broadcast [w v]
ask [] and wait // contrary to what the name of this block would suggest, there is no "ask [] (without waiting)" block - this is why the broadcast is necessary to allow other blocks to run while this block is waiting
say [input received]
stop [all v]

when I receive [w v]
wait (10) secs // although the actual block reads 'seconds', 'secs' is valid in scratchblocks syntax
say [no input received]
stop[all v]

Answer 20

Tcl, 99 bytes

after 10000 {set () no}
vwait [fileevent stdin r {gets stdin (x)}]
puts [lappend () input received]

Answer 21

SmileBASIC 3, 74 bytes

"Accepts input" by waiting for any button press (that should count as input.)

M=MAINCNT@L
N=MAINCNT-M>599CLS?"NO "*N;"INPUT RECEIVED
ON N+BUTTON()GOTO@L

Answer 22

><>, 43 + 6 = 49 bytes

a/!/i0(?\~"input recieved"r>o<
o "\?:-1/r"n

Try it online!

+5 for the -t.08 flag, which sets the tick to 0.08 seconds, and +1 for the a flag, which counts whitespace and skipped instructions as ticks.

The program checks for input about once every second, and exits the loop if input is detected. If input is not received, it exits the loop from the bottom, appending no to the beginning of the string. The initial / is to ensure that the last check for input is exactly on the 10 second mark.

It then takes about 5-6 seconds to print the string itself.

Answer 23

Java 1.4+, 284 bytes

import static java.lang.System.*;public class X{public static void main(String[]x){new Thread(){public void run(){try{Thread.sleep(10000L);}catch(Exception e){}out.print("no input recieved");exit(0);}}.start();new java.util.Scanner(System.in).nextLine();out.print("input recieved");}}

Ungolfed:

import static java.lang.System.*;

public class InputAndWait {
    public static void main(String[] x) {
        new Thread() {
            public void run() {
                try {
                    Thread.sleep(10000L);
                } catch (Exception e) {
                }
                out.print("no input recieved");
                exit(0);
            }
        }.start();
        new java.util.Scanner(System.in).nextLine();
        out.print("input recieved");
    }
}

---

Please don't suggest Version-specific Java improvements, this is a generic Java answer that works in all currently stable Java Environments (1.4 and above).

---

Very freaking wordy... The catch is required, can't throw it. System import shaves off like 5 bytes... Overloading is also wordy, so it ends up a wordy poorly-golfed-looking mess.

Answer 24

Julia 0.6, 78 bytes

Longer than I expected. See comments for "no input recieved" TIO link.

s="input recieved"
Timer(x->(show("no "*s);exit()),10)
readline(STDIN)
show(s)

Try it online!

Answer 25

SmileBASIC, 74 73 bytes

M=MAINCNT
WHILE!I*M>MAINCNT-600I=INKEY$()>"
WEND?"no "*!I;"input received

Takes 1 character of input.

And a 39 byte solution which probably isn't valid (doesn't actually accept text input, just has an OK button that you can press)

?"no "*!DIALOG("",,,10);"input received