UNIX for Dummies Questions & Answers

Hi,

I have small query and a understanding, could you please clarify the query and correct my understanding..?

I am very big log file If i need to take a count and contained lines for a particular pattern/word i am using the grep command twice like the below.

grep -c "OutOfMemoryException" sample.log
grep "OutOfMemoryException" > tmp.txt

This way i think i am using wrong logic i think i can use awk command like

awk '/OutOfMemoryException/' sample.log '{print $0, $NR}'

Please correct me if i am wrong.

Thanks
Senthilkumar

Code:

awk ' /OutOfMemoryException/ { print; CNT++ } END { print "Record Count = " CNT } ' sample.log

... or using a quick shell :

$ grep "OutOfMemoryException" sample.log > tmp.txt; wc -l tmp.txt

... will copy all relevant lines into tmp.txt AND give you the line count after

Is it possible me to check the last 1000 line by using the awk command, I think the only option left for me is first i need to tail it out for 1000 line with grep -c then i need to do a normal grep to get the count and content for a particular pattern for last 1000 lines . Please correct if my understanding is wrong.

Thanks
GCS Support.

Code:

tail -1000 sample.log| awk ' /OutOfMemoryException/ { print; CNT++ } END { print "Record Count = " CNT } '