Linux Log Checking

searching zip files.......

zcat portal-backend.log.2016-08-11.gz | grep zhu98156 -A 100 -B 50

zgrep  'zhu98156' portal-backend.log.*

 

GREP

grep -B 10 -A 10 feb67864 *

Grep with OR

grep -e 2015 -e 2014 -u5

#save output to a file

grep -B 10 -A 10 feb67864 * > nuwan.txt

#exclude files

grep berdell34145 * --exclude=*.gz

Print lines before and after

cat portal-backend.log | grep "ERROR" -A 5 -B 5

grep "ERROR" *.log -A 10 --color=always

save to file

grep -r serieslogos * > nuwan.txt

#save grep output to a file

Grep “transactionId” portal-backend.log > ~/nuwan1.txt

Tail

tail catalina.out //default last 10 lines

tail catalina.out -n 20 //last 20 lines

live update

tail -f *.log *.out | grep --color=always ERROR -A10

add new line between lines

tail -f * | grep ERROR -A5 --color=always| sed G

tail -f /export/home/portal/logs/tomcat/8080/*.log | grep --color=always ERROR -A 10

Clean a file

truncate portal-backend.log --size=0

LESS

G - end of file