Shell Programming and Scripting

i have a script that grep for today date

a=`date +"%F"`--------greps current/today date

wat if suppose i want to grep a date for yesterday...

how to do that using the above format: i,e 2008-01-20

For cshell,
Ksh,

Code:

 TZ=`date +%Z`+24 ; date +%Y-%m-%d

Thanks
Nagarajan G

thanks a lot for ur reply........
i have use ur command like this

TZ=`date +%Z`+24 ; a=`date +%Y-%m-%d`

echo $ a

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i m able to grep yesterday date...can u tell me how to grep 2 day ago and also 3 day ago and likewise in the same format in the above command

The point is we can achieve it by modifying the TZ variable.
If you need yesterday's date then we advance TZ by 24,similarly for 2 days ago advance TZ by 48 ...
For future dates,we ll reduce the TZ by the 24 for 1 day,48 for 2 days and so on..

Thanks
Nagarajan

thanks again to u.now i m able to grep 1 day ago date and likewise in that format.

i need one more help.

TZ=`date +%Z`+48 ; a=`date +%Y-%m-%d`-----------greps 1 day ago date........

but this command greps date in files for 1 day ago date........even the current date is found.....

is there any logic using this command that it will grep the last date entry made in file ,whether it is current date or 1 day ago date or 2 day and likewise

here is the script
---------------------------------------------------

TZ=`date +%Z`+48 ; a=`date +%Y-%m-%d`

for i in *.log*
do
echo "Processing for $i"
count=0
count=`cat $i | grep $a | wc -l`
echo $i >> file1.txt
echo "the last date entry made in file1 is $a" >> file1.txt

done