Redirect stdout and stderr to Function

Question

I need help sending the output (stdin and stdout) from system commands to a bash function, while still accepting input from arguments. Something like the example that follow

Answer 1

It's an old thread.. but I have used it to help me write a log function that will output also multiple lines of a command output:

# Defines function to grab a time stamp #
get_Time () { Time=$(date +%Y-%m-%d\ %H:%M:%S) ; }

write_Log()
{
get_Time
if [ -n "${1}" ]; then         # If it's from a "" then set it
    IN="${1}"
    echo "${Time} ${IN}" | tee -a ${log_File}
else
    while read IN               # If it is output from command then loop it
    do
        echo "${Time} ${IN}" | tee -a ${log_File}
    done
fi
}