I am trying to see a log file using tail -f and want to exclude all lines containing the following strings:
Nopaging the limit is and keyword to remove is
I am able to exclude one string like this:
tail -f admin.log|grep -v "Nopaging the limit is"
But how do I exclude lines containing either of string1 or string2?
8 Answers
Two examples of filtering out multiple lines with grep:
Put this in filename.txt:
abc
def
ghi
jkl
grep command using -E option with a pipe between tokens in a string:
grep -Ev 'def|jkl' filename.txt
prints:
abc
ghi
Command using -v option with pipe between tokens surrounded by parens:
egrep -v '(def|jkl)' filename.txt
prints:
abc
ghi
grep -Fv -e 'Nopaging the limit is' -e 'keyword to remove is'
-F matches by literal strings (instead of regex)
-v inverts the match
-e allows for multiple search patterns (all literal and inverted)
Another option is to create a exclude list, this is particulary usefull when you have a long list of things to exclude.
vi /root/scripts/exclude_list.txt
Now add what you would like to exclude
Nopaging the limit is
keyword to remove is
Now use grep to remove lines from your file log file and view information not excluded.
grep -v -f /root/scripts/exclude_list.txt /var/log/admin.log
egrep -v "Nopaging the limit is|keyword to remove is"
tail -f admin.log|grep -v -E '(Nopaging the limit is|keyword to remove is)'
You can use regular grep like this:
tail -f admin.log | grep -v "Nopaging the limit is\|keyword to remove is"
The greps can be chained. For example:
tail -f admin.log | grep -v "Nopaging the limit is" | grep -v "keyword to remove is"
If you want to use regex:
grep -Ev -e "^1" -e '^lt' -e 'John'
