bash: How to add array elements to command?

Question

I got values in a file that needs to read and added to a command. This is my failing solution...

for arrayValue in "${fileArray[@]}"
do
    curl -s --user "${arrayValue[0]}:${arrayValue[1]}" "https://dyndns.loopia.se?hostname=$arrayValue
done

The file is like this:

username
password
domain
domain
...

Reading from the file is no problem, the problem is how to add them to the curl command.

You are filling fileArray=( < yourfile )? Show the output of declare -p fileArray. (before the loop). And, what is the end your curl command, e.g. "https://dyndns.loopia.se?hostname=$arrayValue..."? — David C. Rankin
– David C. Rankin, Commented Feb 13, 2019 at 7:20
Is the user name and the password in the same array as the other data? — tripleee
– tripleee, Commented Feb 13, 2019 at 7:22
I didn't ask about reading the file, I asked (1) "How are you filling your array?" and (2) "What is the content of your array immediately prior to your loop?" — David C. Rankin
– David C. Rankin, Commented Feb 13, 2019 at 7:24
curl -s --user "${arrayValue[0]}:${arrayValue[1]}" should be curl -s --user "${fileArray[0]}:${fileArray[1]}" — David C. Rankin
– David C. Rankin, Commented Feb 13, 2019 at 7:25

Inian · Accepted Answer · 2019-02-13 07:53:38Z

4

If your array contains the user name and password in the first two elements, and you want to avoid looping over those, try

for arrayValue in "${fileArray[@]:2}"
do
    curl -s --user "${fileArray[0]}:${fileArray[1]}" "https://dyndns.loopia.se?hostname=$arrayValue"
done

Notice how arrayValue refers to the current element out of fileArray. It is not an array, so the references to ${arrayValue[0]} and ${arrayValue[1]} in your attempt were not valid.

Also notice how we loop over the array elements starting from the third with the :2 suffix. (Array indexing is zero-based, so the index 2 refers to the third element.)

edited Feb 13, 2019 at 7:53

Inian

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answered Feb 13, 2019 at 7:25

tripleee

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Comments

oliv · Accepted Answer · 2019-02-13 07:45:07Z

0

Assuming there is no blank character (space, CR...) in the hostname, you could also get rid of the for loop by using printf:

printf -v url "https://dyndns.loopia.se?hostname=${fileArray[@]:2}"

Note the :2 that gets all array elements except the 2 first ones.

Since curl accepts several URL, you can simple use:

curl -s --user "${fileArray[0]}:${fileArray[1]}" $url

answered Feb 13, 2019 at 7:45

oliv

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