log.sh

#!/bin/bash

logfile="my.log"

# Set up a named pipe for logging
npipe=/tmp/$$.tmp
mknod $npipe p

# Log all output to a log for error checking
tee <$npipe $logfile &
exec 1>&- # close stdout, produces 'write error: Bad file descriptor' if not re-opened below

exec 1>$npipe 2>&1 # 2>&1 redirect stderr to stdout
trap "rm -f $npipe" EXIT

# test
ls -al