How do I get the result of a command from a remote server using ssh?-CodePudding

I am working in Linux bash (version 16.04.4 LTS). I am using ssh to connect to a remote server where I want to find for a specific file from a list of files (most recent file version) and then retrieve only the version. For example, considering this files on the remote server (server.com):

file-30.0-2.tar.xz
file-30.0-3.tar.xz
file-30.0-4.tar.xz
file-30.0-5.tar.xz
file-30.0-7.tar.xz
file-30.0-10.tar.xz

If I login directly in the remote server and If I try the following command it works.

ls file-*.tar.xz | sort -V | tail -n1 | grep -o '[[:digit:]]\ .[[:digit:]]\ .[[:digit:]]\ '

Output: 30.0-10

As I am working from another server I am using ssh to connect to remote server like this:

#!/bin/bash
set -euxo pipefail

ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o PreferredAuthentications=publickey [email protected] "cd /myDir; \\
  ls file-*.tar.xz | sort -V | tail -n1 | grep -o '[[:digit:]]\ .[[:digit:]]\ .[[:digit:]]\ ')"

This command it's working and I get the same output as before (30.0-10).

But I want to be able to pass that result (30.0-10) to outside the script and use it in the local server.

Any ideas?

CodePudding user response：

Print null delimited file list remotely, sort it by reverse major version, and patch version, so the latest is listed first

read -r -d '' latest_archive < <(
  ssh \
    -o UserKnownHostsFile=/dev/null \
    -o StrictHostKeyChecking=no \
    -o PreferredAuthentications=publickey \
    [email protected] \
    printf '%s\\0' '/my/dir/file-*[[:digit:]].tar.xz' | sort -zt- -k2nr,3nr
)

How it works:

printf '%s\\0' '/my/dir/file-*[[:digit:]].tar.xz': Prints null-delimited list of files matching the pattern.
| sort -zt- -k2nr,3nr: Pipe to sort -z null-delimited entries, -t- with dash - as field delimiter, -k2nr,3nr on 2nd field numerically, largest first, combined with 3rd field numerically and also largest first.

CodePudding user response：

Simply assign the output of your script to a variable and later use that variable:

result="$(./yourscript)"
echo "Result from SSH = $result"