echo/warning/error messages in the bash shell

Reference from the kamailio source, scripts/kamdbctl.base
mdbg() {
if [ "0$VERBOSE" -ne 0 ] ; then
if [ -t 1 -a -z "$NOHLPRINT" ] ; then
echo -e "\033[1m$1\033[0m"
else
echo "$1"
fi
fi
}

mwarn() {
if [ -t 1 -a -z "$NOHLPRINT" ] ; then
echo -e '\E[37;32m'"\033[1mWARNING: $1\033[0m"
else
echo "** WARNING: $1"
fi
}

minfo() {
if [ -t 1 -a -z "$NOHLPRINT" ] ; then
echo -e '\E[37;33m'"\033[1mINFO: $1\033[0m"
else
echo "** INFO: $1"
fi
}

mecho() {
if [ -t 1 -a -z "$NOHLPRINT" ] ; then
echo -e "\033[1m$1\033[0m"
else
echo "$1"
fi
}

merr() {
if [ -t 1 -a -z "$NOHLPRINT" ] ; then
echo -e '\E[37;31m'"\033[1mERROR: $1\033[0m"
else
echo "** ERROR: $1"
fi
}