Shell Programming and Scripting

Hi,

I am new to shell scripting and is working on a script to extract lines from a log file between two time stamps using awk command. After some research I used following command:

Code:

awk '/01 Oct 2011/{p=1} /10 Oct 2011/{p=0} p' test.log >> tmp.log

This works fine. But now i want to convert the hard coded dates to variable and have following command, but that does not work. I do not see any error message either

Code:

date1="16 Oct 2011"
date2="17 Oct 2011"
awk -v "d1=${date1}" -v "d2=${date2}" '/d1/{p=1} /d2/{p=0} p' test.log >> tmp.log

Any help on this would be greatly appreciated. If you think there is a better way of doing this then please suggest.

Thanks in advance...

Give a try with :

Code:

 awk -v d1="${date1}" -v d2="${date2}" '$0~d1{p=1} $0~d2{p=0} p' test.log >> tmp.log

Thanks... that works perfectly... can you please explain me the usage '$0~d1{p=1} $0~d2{p=0} p'. So i have a better understanding of this

This code use p as a flag. The flag is turned on and off with 1 and 0.
By default a non zero value means 'TRUE' otherwise 'FALSE', if the last awk instruction (here: p ) is true, then the current line is printed, if false, nothing is printed.
This is the default behaviour of awk for displaying stuff until another behaviours is explicitly coded with print/printf/getline/next or some other instruction that may have an influence on the output.