How to echo something every 4 minutes while in an endless loop

Question

I have a script that uses while(true) to run so it runs forever until it dies. I want to be able to make it echo something once every 4 minutes, how can i do this? The script runs on command prompt and it uses while(true) so its confusing plus i am not sure how to make it do that every 4 minutes. How can i make it echo something once every 4 minutes while still in a while(true)?

Are you trying to spawn a server process to do some work from PHP or is this a local script that you are executing? — jheddings, Oct 13 '12 at 22:51

Baba · Answer 1 · 2012-10-15T12:57:13.980

7

You can try

while(true)
{
    sleep(240); // sleep for 240 sec
    echo " Hello World" ;
}

Or

$time = time();
while ( true ) {
    /*
     * Play Some Ball
     */

    if ((time() - $time) >= 240) {
        echo date("Y:m:d g:i:s"), PHP_EOL;
        $time = time();
    }
    sleep(2);
}

Output Test with Time = 2 sec, Sleep = 1 sec

2012:10:14 12:50:56
2012:10:14 12:50:58
2012:10:14 12:51:00
2012:10:14 12:51:02
2012:10:14 12:51:04
2012:10:14 12:51:06
2012:10:14 12:51:08
2012:10:14 12:51:10
2012:10:14 12:51:12
2012:10:14 12:51:14

edited Oct 15 '12 at 12:57

answered Oct 13 '12 at 22:45

Baba

92,047
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2

i cant make it sleep because i need it active. – Matt Jenkins Oct 13 '12 at 22:47
2

I would always recommend a small sleep on a tight loop that will run forever. That or some other yielding method to avoid an all-consuming loop. – jheddings Oct 13 '12 at 22:55
@jheddings i totally agreed with you ... Nice one – Baba Oct 13 '12 at 23:00
@jheddings Too bad have exceeded by daily reputation ... Thanks :) – Baba Oct 13 '12 at 23:03
1

yup small sleep to give job scheduler a change using something like usleep. – Alfred Oct 13 '12 at 23:13

Lix · Answer 2 · 2012-10-13T22:53:17.180

3

Using a sleep method will actually halt your script from running. I'm not 100% if this is what you want to happen.

Another way to attack this issue would be to compare timestamps from the last "echo" command on each iteration.

$echo_time = time();
$interval = 4*60;
while(true){
  if ($echo_time + $interval >= time()){
    echo "$interval seconds have passed...";
    $echo_time = time(); // set up timestamp for next interval
  }
  // other uninterrupted code goes here.
}

This will allow your code within your loop to continue running and only check the times at the start of each iteration.

edited Oct 13 '12 at 22:53

answered Oct 13 '12 at 22:48

Lix

46,307
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In php7 `echo "$interval seconds have passed..."; ` should be: `echo $interval . "seconds have passed...";` Or: `echo $interval . 'seconds have passed...'; // single quot is faster than double quot` – jagb Mar 04 '17 at 18:10

score 1 · Answer 3 · answered Oct 13 '12 at 22:47

1

Try adding in a loop of while(true) { ... } sleep() parameter function.

$sleep = 4*60;
while(true)
{
    # waiting...        
    sleep($sleep);
    # work after 240 mins
}

answered Oct 13 '12 at 22:47

Marin Sagovac

3,867
5
22
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How to echo something every 4 minutes while in an endless loop

3 Answers3

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