proc_name proc.num[proc_name] directive

[disparo]

Full Process name in 'ps -ax' is :

/usr/sbin/php /opt/scripts/drv.php

trying such item:

proc.num[/usr/sbin/php /opt/scripts/drv.php]

result is - 0.

another try:

proc.num[drv.php]

result is 1.

Okay! Now full process name in 'ps -ax' is:

/usr/sbin/php /opt/scripts/drv.php --config=/etc/look.conf

trying again

proc.num[drv.php]

and result is always - 0.

So, which part of process name using by this zabbix directive?