curl is executed twice from crontab

Question

I have installed centos 7 and PHP 5.6.29 on my server, and I set up crontab to run this command every 15 minutes:

*/15 * * * * curl http://example.com/check.php

but the command is run twice. Is there a way to fix this problem?

When I run the command manually from the command line:

curl http://example.com/check.php

it works, but when it is run via crontab it runs twice.

I checked with wget in place of curl but the problem is the same.

Answer 1

Check if you have more than one cron daemon running

ps -ef | grep crond

See this.