In addition to what Scrutinizer and RudiC have already pointed out...

There is a HUGE difference between $result.csv and result.csv unless somewhere in your script you also had a shell assignment statement like:
result=result

If you want our help debugging your script, you need to show us your script! (Not just bits and pieces that work fine when you run them separately, but don't work in your whole script.) Most of us aren't very good at guessing what:

Code:

..... (matching fields script using awk)

and:

Code:

.....

actually expand to in your script, but it obviously makes a huge difference in what your script will do.

Are you trying to remove all but the 1st line in your file for each unique field one value, and hoping that sort -u will do that for you? Or, are you trying to remove all but the 1st line in your file for each unique field one value and also need to sort the output?

What operating system (including release numbers) and shell are you using? Do you need to be able to run this script only on that operating system, or are you trying to write portable code that will work on any UNIX or Linux system?

If you have a problem to solve, stop and think about what the problem is. Describe the entire problem. Describe your inputs. Describe your desired outputs.

Piecewise refinement is great when you've got a big problem to solve, but if you don't know your end target when you start, a lot of those pieces may be wasted since they won't lead to your final goal.

Please help us help you. Tell us in detail, about your inputs, your outputs, and the code you've tried to get to your goal.