Calling another program in a shell script and using the returned data

Question

I have a c program named calculate which sorts out the correct data

Data input (initial file.txt):

abcd!1023!92
ckdw!3251!io
efgh!9873!xk

Data returned:

abcd!1023!92
efgh!9873!xk

My shell script contains:

./calculate | awk -F '!' '{sum += $2} END{print sum}' "$1"

When I run the script ./check file.txt it ignores the values returned from the calculate function and instead calculates from the input file.

How do I fix this so that the "awk" function works from the data returned from the ./test function?

Make sure you don't name your test scripts as 'test'. On linux, 'test' in an existing program, and if you forget to use ./ then you might wonder what's wrong. — Deanie
– Deanie, Commented Mar 31, 2015 at 15:27
@Deanie it was actually called calculate just tried to rush the unimportant parts — Kadana Kanz
– Kadana Kanz, Commented Mar 31, 2015 at 15:30

Etan Reisner · Accepted Answer · 2015-03-31 15:32:42Z

1

You are passing a file to the awk script as well as input.

./calculate | awk -F '!' '{sum += $2} END{print sum}' "$1"

awk only uses one or the other and it prefers file arguments when given.

Drop the "$1" bit from there.

answered Mar 31, 2015 at 15:32

Etan Reisner

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Comments

josegomezr · Accepted Answer · 2015-03-31 16:21:02Z

1

I did my try.

sorting.sh (my version of your filtering program)

#!/usr/bin/env bash
egrep 'a|e' input.txt

program.sh (your shell command)

./program.sh | awk -F '!' '{sum += $2} END{print sum}'

@Updated, deleted "$1" as stated by Etan Reisner

answered Mar 31, 2015 at 15:32

josegomezr

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Stick that pipeline in a script and pass the input file as an argument to the script and you'll see the problem.

@josegomezr my program was working. I just removed the "$1" like the other answer indicated and it seems to work fine!