[SOLVED] how to get a total sum which is having both addition and subtraction sign in bash?

Issue

I am having a file a.txt from that i grep a line start with A and cut 3 to 7 index character and try to sum them but problem is that it is also having (-) sign how I am able to do that.

I am working on linux server and tried many script but not able to find a solution.

and using this code its doing addition but i also want to do subtraction according to sign

grep "^A" a.txt |cut -c3-7 |awk '{SUM += $1} END {print SUM}'

original file contains:

A05000+
B05005-
C05845+
A05007-
A05648+

Should evaluate like:

5000+ 5007- 5648, resulting in 4359.

Expexted output: 5641

getting Output: 15655

Solution

Here is one awk variation.

awk '/^A/ {s+=substr($1,7,1) substr($1,2,5)} END {print s}' file
5641

+5000+-5007+5648=5641

Answered By - Jotne