Recently there is a scheduled task on the server, I set it as:
*/25 * * * * ccc /xxx/xxx
Then tell the test classmates: Execute once every 25 minutes;
In order to confirm, the test students asked again: Is it executed every 25 minutes?
I'm not too sure about this question. . . (Actually, when I set 25, my heart was already beating drums...)
Because the examples given in the various "crontab details" on the Internet are:
*/1 // means to execute once every minute
*/5 // means to execute every 5 minutes
*/10 // means to execute every 10 minutes
But 1, 5, and 10 are all divisible by 60. What about 25 ?
So I did a test:
*/25 * * * * /usr/local/bin/php "/var/www/html/cron.php"
php code:
<?php
mkdir('/var/www/html/'.date('H-i-s',time()));
?>
And the result is:
The execution time is: 0 minutes, 25 minutes, 50 minutes every hour, not 0, 25, 50, 15, 40. . .
That is, every time a new hour is entered, the minutes are recalculated.
So, "*/n * * * *" is not when n is not divisible by 60: execute every n minutes