Expanding a variable inside quotes

Question

am trying to get the files from S3 bucket,starting with certain prefix. To do so am using aws cli command in the bash script.

Below is my code

#!/bin/bash  

FILESIZE=$(mktemp)
declare -a files=( "A1S0" "D1S0" "D2S0" "D3S0" "D4S0" "D5S0" "D6S0" )
for n in "${!files[@]}"; do
    printf '%8d  %s\n' "${n}" ${files[n]}
 echo aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query "Contents[?contains(Key, '${files[n]}$(date +%m%d)')]" 

done

In my code there is a problem when expanding variables inside the quotes, $(date +%m%d)**Date variable is expanding but i need to avoid single quotes **'A1S00526' . How can i do that Pls help me

Output:

aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'A1S00526')]
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'D1S00526')]
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'D2S00526')]
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'D3S00526')]
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'D4S00526')]
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'D5S00526')]
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, 'D6S00526')]

Expected output:

 aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, A1S00526)]
    aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, D1S00526)]
    aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, D2S00526)]
    aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, D3S00526)]
    aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, D4S00526)]
    aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, D5S00526)]
    aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query Contents[?contains(Key, D6S00526)]

Can someone pls help me to expand the variables inside the quotes

When i run code as below, please find the attached output

aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query \'"Contents[?contains(Key, ${files[n]}$(date +%m%d))]"\'

Answer 1

This is what you need to do:

#!/bin/bash

FILESIZE=$(mktemp)
declare -a files=("A1S0" "D1S0" "D2S0" "D3S0" "D4S0" "D5S0" "D6S0")
for n in "${!files[@]}"; do
    #printf '%8d  %s\n' "${n}" ${files[n]}
    echo aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query \'"Contents[?contains(Key, ${files[n]}$(date +%m%d))]"\'
done

The output will be:

aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, A1S00526)]'
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, D1S00526)]'
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, D2S00526)]'
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, D3S00526)]'
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, D4S00526)]'
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, D5S00526)]'
aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query 'Contents[?contains(Key, D6S00526)]'

Answer 2

If you write you echo as

echo aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query "Contents[?contains(Key, ${files[n]}$(date +%m%d))]" 

you will get exactly the output you expected. If you actually want to run the command, and it is important that the quotes are passed to aws , it becomes

for n in "${!files[@]}"; do
  printf '%8d  %s\n' "${n}" ${files[n]}
  aws s3api list-objects --bucket ui-dl-weather-ecmwf-ltf --prefix daily/ --query "Contents[?contains(Key, '${files[n]}$(date +%m%d)')]" 
done

In short: You want the quotes, you put them in. You don't want them, you leave them out.