Question

I have a PHP script, which does something in a matter of seconds (not running for a long time). I need this script to be executed, let’s assume, 12 (this can change) times a day. 24 / 12 = 2 hours.

I could just execute the script each 2 hours, but I need it to be randomized along the 24 hours.

That means that script doesn’t have to be executed at 01:05 PM, 03:05 PM, 05:05 PM, but rather at 01:37 PM, 03:11 PM, 05:46 PM. I guess you’ve understand the point. Sorry for not being very clear.

(cron & other tools (if required) can be installed. running debian 6)

Bounty (100 rep) will be offered for a working solution.

Answer 1

Let’s say you want your script to run N times a day. Then create a bash script my_php_runner.bash like the following:

#!/bin/bash

N=12  # 50 times a day

let WAIT_TIME=86400/$N

while [[ $n -gt 0 ]]; do
    php yourscript.php

    # Sleep for $WAIT +/- 300 seconds
    sleep $(( $WAIT - 300 + $RANDOM%600 ))
    ((n--))
done

It will run your script 12 times, waiting between 115 and 125 minutes between runs. Then add something like

0 0 * * * my_php_runner.bash

in cron to run the bash script once a day.