Bash: nested for loop + middle loop contains two arrays?

Question

Maybe I'm over-thinking this but here's my desired output:

one four seven 
one five eight
one six nine
two four seven
two five eight
two six nine
three four seven
three five eight
three six nine

Here's what I started. I got to the second for loop and totally lost my mind trying to find the solution.

#!/bin/bash

declare -a aaa=("four" "five" "six")
declare -a bbb=("one" "two" "three")
declare -a ccc=("seven" "eight" "nine")


for bs in ${bbb[@]}; do
  for as in ${aaa[@]}, cs in ${ccc[@]}; do
    echo "$bs" "$as" "$cs"
  done
done

choroba · Accepted Answer · 2017-09-20 08:03:17Z

1

You can't have more than one in in a for clause.

If you need to iterate two arrays simultaneously, iterate over their indices:

#! /bin/bash

declare -a aaa=("four" "five" "six")
declare -a bbb=("one" "two" "three")
declare -a ccc=("seven" "eight" "nine")

for b in "${bbb[@]}" ; do
    for i in "${!aaa[@]}" ; do  # or ccc
        echo "$b" "${aaa[i]}" "${ccc[i]}"
    done
done

edited Sep 20, 2017 at 8:03

answered Sep 20, 2017 at 7:02

choroba

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2 Comments

zewiblzd Over a year ago

Thanks for your answer. I've updated my original question to better address my problem. I over-simplified the issue originally. Thanks for your help though. I would be grateful if you tried to solve this again.

choroba Over a year ago

@zewiblzd: Updated. Next time, please ask a new question if it's significantly different to the original one.

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