bash return code after reading for pipe

Question

How to return $code as the exit code for this script and not the exit code of the last command rm "${fifo}".

#!/bin/bash

fifo=myPipe
mkfifo "${fifo}"|| exit 1
{
    read code <${fifo}
} | {
    timeout 1 sleep 2
    timeoutCode=$?
    echo "${timeoutCode}" >${fifo}
}
rm "${fifo}"

Answer 1

Perhaps this can serve your purpose:

This answer has 2 parts, which you were looking for:

1. Set $? to any required value
2. Use ${PIPESTATUS[@]} array to obtain exit status of individual stages of the pipeline...

Code:

#!/bin/bash

return_code() { return $1; }    # A dummy function to set $? to any value

fifo=myPipe
mkfifo "${fifo}"|| exit 1
{
    read code <${fifo}
    return_code $code
} | {
    timeout 1 sleep 2
    timeoutCode=$?
    echo "${timeoutCode}" >${fifo}
}
ret=${PIPESTATUS[0]}
rm "${fifo}"
exit $ret

Considering that the expected exit code of the entire script is actually being generated via stage 2 of the pipeline, below logic would also work.

#!/bin/bash

    fifo=myPipe
    trap "rm $fifo" EXIT #Put your cleanup here...

    mkfifo "${fifo}"|| exit 1
    {
        read code <${fifo}
    } | {
        timeout 1 sleep 2
        timeoutCode=$?
        echo unused > ${fifo}
        exit $timeoutCode
    }