bash to pass array to ssh to another server

Question

In the below bash I am trying to pass the ${array[$i]} to ssh after changing to a specific directory, but ${array[$i]} it is not recognized? The goal is to use the id in ${array[$i]} (there may be more than 1) to further go into that directory. The bash seems to work as expected except for the ${array[$i]} not be passed.

bash

readarray -t array <<< "$(printf '%s\n' $id)"
for ((i=0; i<${#array[@]}; i++ )) ; do
   echo "${array[$i]}"
done

 sshpass -f file.txt ssh -o strictHostKeyChecking=no -t xxx@xxx "${array[$i]}" 'cd path/to/folder/"$array[$i]" && exec bash -l'
 echo ${array[$i]}

maybe?

readarray -t array <<< "$(printf '%s\n' $id)"
for ((i=0; i<${#array[@]}; i++ )) ; do
   echo "${array[$i]}"
done

 for i in "${array[$i]} ; do
 sshpass -f file.txt ssh -o strictHostKeyChecking=no -t xxx@xxx "${array[$i]}" 'cd path/to/folder && exec bash -l'
done

contents of array[$i] ---- array[$i] will be different in number each time but the format will always be the same ----

00-0000-xxx-xxx-xxx
00-0001-yyy-yyy-yyy

desired ssh

cd path/to/folder/00-0000-xxx-xxx-xxx && cp *.txt* /home/location
cd path/to/folder/00-0000-yyy-yyy-yyy && cp *.txt* /home/location

As a future note, printf '%s\n' "${array[@]}" is a much easier way to print all array contents one-line-to-an-item. — Charles Duffy
– Charles Duffy, Commented Oct 11, 2019 at 14:58
That said, because array contents can contain literal newlines, the above isn't a safe serialization format; only NULs aren't allowed to be present inside elements (which is why they're what you should use). — Charles Duffy
– Charles Duffy, Commented Oct 11, 2019 at 14:58
Anyhow, I don't know how/why you expect the above code to work, or even what "working" means in its context -- the sshpass command isn't in a loop at all, f/e; and when you pass multiple arguments to ssh, they're just concatenated together into a single shell command. — Charles Duffy
– Charles Duffy, Commented Oct 11, 2019 at 14:59
...so, when you pass "${array[$i]}" as an extra argument: (1) what kind of thing do you expect it to contain? (2) how, and why, do you expect the remote shell to parse that opaque thing you aren't showing us in any particular way? — Charles Duffy
– Charles Duffy, Commented Oct 11, 2019 at 15:00
I'm not saying that, because I don't understand what you're actually trying to do, so I can't say anything useful and specific (and afaict, neither can anyone else). Do you want only one ssh connection to happen passing all the array elements across at the same time? Do you want one connection per element? ...? — Charles Duffy
– Charles Duffy, Commented Oct 11, 2019 at 15:42

Charles Duffy · Accepted Answer · 2019-10-11 17:31:53Z

1

Here, we generate a single remote that runs (cd ... && exec cp) for each array element, with each in a subshell to prevent the cd from having side effects on subsequent elements' commands:

printf -v cmd_q '(cd /path/to/folder/%q && exec cp -- *.txt* /home/location)\n' "${array[@]}"
sshpass -f file.txt ssh -o strictHostKeyChecking=no -t xxx@xxx "$cmd_q"

The exec is a minor performance enhancement, consuming the subshell started with the parenthesis by replacing it with the cp process.

The %q placeholder in the printf format string gets substituted with the individual array values.

edited Oct 11, 2019 at 17:31

answered Oct 11, 2019 at 16:00

Charles Duffy

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1 Comment

justaguy Over a year ago

Thank you very much for your help and explanation :)

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