Shell Programming and Scripting

Originally Posted by ahamed101

Try this...

Code:

echo $i | md5sum | grep -v ^000000 >> /home/ubuntu/Documents/log

--ahamed

Originally Posted by jremio

Thanks will try it as soon as i get to a linux terminal... thanks a lot for the assistance!

---------- Post updated at 06:50 PM ---------- Previous update was at 06:34 PM ----------

Hi i tried your grep code, didnt work as planned.

in order to test i wrote this small code....

for i in $(seq -w 100000 100100)
do

echo $i | grep -v ^100088 >> /home/ubuntu/Documents/test_log

done

it didnt stop at 100088 but went all the way to 100100.

Originally Posted by ahamed101

The code provided wasn't supposed to stop there... Your request was not to include any hash strings starting with 0000...

--ahamed

Originally Posted by jremio

I got one problem though, when the echo logs into the log file, is there any way to make it stop when one of the md5sum starts with 000000?

Originally Posted by azaria

this works for me:

for i in $( seq -w 0000 9999);
do
hash=`echo $i | md5sum`;
echo $hash >> /tmp/somefile;
if [ `echo $hash|cut -c -4` == '0000' ];
then
break;
fi;
done;

However... it seams there are no hashes that start with four zeros.
You can verify this by changing the condition to:
if [ `echo $hash|cut -c -3` == '000' ];

or even removing the condition and then greping the output file for '^0000' (i.e. lines with four zeros at their beginning.

PS. Note that while this does work, it is not very efficient. As all the piping invokes subshels. 10Kiterations, with quite a few subshells in each iteration.... plenty of room for optimization. ;-)