Watching Log Files Using tail and less

Watch the error log and filter the output to the screen (using grep).

tail -f /var/log/apache/error.log | grep -v Exception | grep -v 'PHP Notice'

Output the error log to the screen, filter it before doing so (using grep).

less +F /var/log/apache/error.log | grep -v Exception | grep -v 'PHP Notice'

Note:

-v parameter in grep is reverse look up. It mean, all text except 'Exception' and 'PHP Notice'

Forward and Backward Search in less

/ – search for a pattern which will take you to the next occurrence. 

? – search for a pattern which will take you to the previous occurrence. 

n – for next match in backward direction 

N – for previous match in forward direction

Shift F - similar to tail -f