DevStack-style log redirection wrapper

logtest.sh

#!/bin/bash
# Test stack.sh logging scenarios

LOGFILE=${LOGFILE:-test.log}
SUMFILE=sum.log
VERBOSE=${VERBOSE:-True}

# Kill background processes on exit
trap exit_trap EXIT
function exit_trap {
    local r=$?
    jobs=$(jobs -p)
    if [[ -n $jobs ]]; then
        echo "exit_trap: cleaning up child processes"
        kill 2>&1 $jobs
    fi
    exit $r
}

# Exit on any errors so that errors don't compound
trap err_trap ERR
function err_trap {
    local r=$?
    set +o xtrace
    if [[ -n "$LOGFILE" ]]; then
        echo "${0##*/} failed: full log in $LOGFILE"
    else
        echo "${0##*/} failed"
    fi
    exit $r
}


echo "Before"
ls -l /proc/self/fd
echo -e "\n\n"
sleep 1

# set up file handles like stack.sh
if [[ -n "$LOGFILE" ]]; then

    # Copy stdout to fd 3
    exec 3>&1
    if [[ "$VERBOSE" == "True" ]]; then
        # Redirect stdout/stderr to tee to write the log file
        exec 1> >( awk -v logfile=${LOGFILE} '
                /((set \+o$)|xtrace)/ { next }
                {
                    cmd ="date +\"%Y-%m-%d %H:%M:%S.%3N | \""
                    cmd | getline now
                    close("date +\"%Y-%m-%d %H:%M:%S.%3N | \"")
                    sub(/^/, now)
                    print
                    print > logfile
                    fflush("")
                }' ) 2>&1
        # Set up a second fd for output
        exec 6> >( tee "${SUMFILE}" )
    else
        # Set fd 1 and 2 to primary logfile
        exec 1> "${LOGFILE}" 2>&1
        # Set fd 6 to summary logfile and stdout
        exec 6> >( tee "${SUMFILE}" >&3 )
    fi
else
    # Set up output redirection without log files
    # Copy stdout to fd 3
    exec 3>&1
    if [[ "$VERBOSE" != "True" ]]; then
        # Throw away stdout and stderr
        exec 1>/dev/null 2>&1
    fi
    # Always send summary fd to original stdout
    exec 6>&3
fi

# try stuff here

echo "During"
ls -l /proc/self/fd
echo -e "\n\n"
sleep 1

# tear down redirection

if [[ -n "$LOGFILE" ]]; then
    exec 1>&3
    # Force all output to stdout and logs now
    exec 1> >( tee -a "${LOGFILE}" ) 2>&1
else
    # Force all output to stdout now
    exec 1>&3
fi

echo -e "\nAfter:"
ls -l /proc/self/fd