Advanced Script Help....PLEASE!!!!

[peopleperson88]

I'm attempting to create a database for an ATM project that I'm working on.

Here is what I have so far.
A script called nawk.test. This file is used to find the member's number and then subtract the amount given from their current balance, then publish the results.

I need to be able to 1) find the balance, 2) calculate
the new balance (old balance - withdraw amount) and 3) substitute it back into the database.

I can get #1 and #2 - but cannot get the statement to
publish the new value correctly back into the database.

Here is how I am executing the script.

nawk.test 111111 50
[script][member number][withdrawl amount]

MEM=$1
FIELD=10
old_balance=`nawk ' BEGIN { FS = ":" } /^'$1'/ { print $10 } ' data_base`
new_balance=`expr $old_balance - $2`
nawk -F: -v field=$FIELD change=$new_balance ' $1 ~ /$MEM/ {$field=change;OFS=":";print $0} ' data_base >> data_base2
echo $old_balance
echo $new_balance



Here is the database that I am working with.
File name is database.

[Member Number][Fname][MI][LName][Address][ST][Zip][Balance][Last Amount][Last Type (withdrawl, deposit, etc..)]

11111:BOB:JONES:9909 Hoyt Way:Westminster:CO:80021:CHECKING:5000:200
22222:CHARLES:AETERS:1800 Test Street:Carter Lake:CO:80052:CHECKING:20000:50:W
33333:MARY:X:SMITH:1234 Wadsworth Blvd:Broomfield:CO:80021:CHECKING:10000:200:W


Someone plesae help me. I have been working on this for a very long time and can NOT figure this one out.

Thanks

 

[olded]

Peopleperson:

nawk -F: -v field=$FIELD -v change=$new_balance '
$1 ~ /'$MEM'/ { $field=change; print $0 } ' data_base > data_base2

Your problems:

1) Need -v before change variable
2) Need quotes around $MEM variable
3) OFS=":" is unnecesary

While your solution works, you could solve this problem in one awk script. You'd not only save one call to nawk, but a call to expr.

Also, you might consider posting questions like this in the unix scirpting or awk forums.

Regards,


Ed

 

[jared71]

When you say "replace" it, I assume you mean that you want the new value "in place of" the old value? I suggest you take a look at sed's find an replace feature.

-jared

ps- this sounds like a school assignment..