BASH: Capturing both the output and the exit code of a process

Of course I found an answer to this in a collection of Stack Overflow questions, but to make things easier for anybody who might stumble into this post (and mainly for Future Me), here’s the answer.

Basically I have a command that sometimes produces an error, but usually just re-running it produces the correct output. When it encounters an error, it dutifully sets its error code to something other than 0 (success). But how to I capture both the command’s output and its exit code? This way.

output=$(myCommandWhichSometimesDoesntWork)
exit_code=$? # This HAS to be exeuted right after the command above

So I made a little wrapper script that repeatedly calls the first one until it gets an answer, with a set maximum number of retries to avoid infinite loops.

#!/bin/bash
retries=0
max_retries=10 # Change this appropriately
 
# The "2> /dev/null" silences stderr redirecting it to /dev/null
# The command must be first executed outside of the while loop:
# bash does not have a do...while construct
output=$(myCommandWhichSometimesDoesntWork 2> /dev/null)
while [[ $? -gt 0 ]]
do
        ((retries++))
        if [[ retries -gt max_retries ]]
        then
                exit 1
        fi
 
        output=$(myCommandWhichSometimesDoesntWork 2> /dev/null)
done
 
echo $output

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