Bash - Passing value to both console and variable/file

Question

I prepared a simple logger with a function logMETHOD:

function logMETHOD {
    exec 5>&1
    local log

    log="$( "$@" 2>&1 | tee /dev/fd/5; echo ${PIPESTATUS[0]}>/tmp/ssg_retval )"
    local retVal=$(</tmp/ssg_retval)
    rm -f /tmp/ssg_retval

    _LOG_SSG+=$log$'\n'
    return $retVal
}

It is great. It puts output of a passed method into both console (through /dev/fd/5) AND variable log (through /dev/fd/1) at the same time. It also returns value returned by the passed method. Eg.

logMETHOD scp test.txt ala@host:/direcotry

It works, but unfortunately I can't use it, cause I have no access to /dev/fd/5 on the server I need to use. "Permission denied".

I tried to use a temporary file instead of a file descriptor but it breaks dynamic output like scp progress bar.

Is there any way to implement this functionality without using file descriptors?

Answer 1

It appears that you have permission to use &5 but not to use /dev/fd/5. You could try to trace down why by running ls -l /dev/fd/5 and comparing that to the user+group that your script runs under. It may be simpler, though, to just try replacing:

tee /dev/fd/5;

With:

tee >(cat >&5)