UNIX for Dummies Questions & Answers

I am grepping a log file but want to filter out more than one thing..

Code:

tail -f log | grep -vi "FTP session"

How can I add more filters to this string?

Can I do

Code:

tail -f log | grep -vi "FTP session" | grep -vi "xxx"

or is there a better method.

Thanks

Moderator's Comments:

Use code tags please, ty.

Code:

tail -f log | grep -vEi "FTP session|xxx"

Code:

tail -f log | grep -Evi "(FTP Session|xxx)"

Try

Code:

grep -viE "ftp session|xxx"

> tail -f ncolog | grep -viE "(FTP sess|LOG)"
grep: illegal option -- E

Usage: grep -hblcnsviw pattern file . . .

> tail -f ncolog | grep -vEi "(FTP sess|LOG)"
grep: illegal option -- E

Usage: grep -hblcnsviw pattern file . . .

> tail -f ncolog | grep -vEi "FTP sess|LOG"
grep: illegal option -- E
Usage: grep -hblcnsviw pattern file . . .

Code:

egrep -vi '(ftp session|xxx)'

which is NOT the same as:

Code:

grep -vi "FTP session" | grep -vi "xxx"

vgersh99 is right of course - the 3 solutions provided by the others and me are a logical "or" while the grep piped into another grep is a logical "and" and sowith wrong.
Currently I have no better idea but two greps - you could of course use something like

Code:

tail -f ncolog| awk '/FTP session/ && /xxx/'

For the -i to ignore case, you might adjust the two patterns or use something like "tolower($0)", but I am not sure if this is worth writing instead of two piped greps.