Get the matching string prefix

Hi, I would like to exact the first X character of a string S1 where X is the lenght of a string S2. How to do that in shell ksh script

Here is my testing script

#/bin/ksh
OUT_DATA="ABCDEFGHIJKLMN 111111 22222"
MMM="ABCDEFG"
 
echo "OUT_DATA = $OUT_DATA"
 
EEE=`echo $OUT_DATA | awk -F "ABC" '{printf("%s", $1)}'`
FFF=`echo $OUT_DATA | awk "ABC" '{printf("%s", $1)}'`

echo "EEE = $EEE"
echo "FFF = $FFF"

DDD=$(echo $OUT_DATA |awk '{print substr($0, 0 , 7))}')

Both EEE and FFF returns empty string.
DDD is okay, I am getting ABCDEFG back
But, how do i make it more dynamic? That is, somehow the length field in substr can
be determined based on the length of $MMM
tommym121Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

tommym121Author Commented:
Ah, I find a solution.

YY=`expr length $MMM`  
GGG=$(echo $OUT_DATA | cut -c1-$YY)
echo "GGG = $GGG"

GGG = ABCDEFG

Any better idea?

It works.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
ozoCommented:
Did you mean
EEE=`echo $OUT_DATA | awk -F "ABC" '{printf("%s", $2)}'`
0
ozoCommented:
or did you mean
DDD=${OUT_DATA:0:${#MMM}}
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Shell Scripting

From novice to tech pro — start learning today.