I am passing a list of regex patterns to grep
to check against a syslog file. They are usually matching an IP address and log entry;
grep "1
patterns[1]="1\.2\.3\.4.*Has exploded"
patterns[2]="5\.6\.7\.8.*Has died"
patterns[3]="\!9\.10\.11\.12.*Has exploded"
for i in {1..3}
do
grep "${patterns[$i]}" logfile.log
done
should be the the same as
egrep "(1\.2\.3\.4.*Has exploded|5\.6\.7\.8.*Has died)" logfile.log | egrep -v "9\.10\.11\.12.*Has exploded"