Plugin wordpress for graylog

Hello ladies and gentlemen,

I’m developping a wordpress ‘s plugin for sending my error log on a graylogserver.

I’m using the library gelf php, i create my script but now i don’t know what to do.

How can my script can execute when an erroc occured ?
I know Drupal have a function called watchdog but i don’t know if WP can do the same thing.

If it’s impossible i’m still looking a solution for this problem