What is the meaning of success & failure in shell script? - bash

Question

In this init script you can see lines which say only success or failure.
What are these commands?
start)
echo -n "Starting Jenkins "
daemon --user "$JENKINS_USER" --pidfile "$JENKINS_PID_FILE" $JAVA_CMD $PARAMS > /dev/null
RETVAL=$?
if [ $RETVAL = 0 ]; then
success
echo > "$JENKINS_PID_FILE" # just in case we fail to find it
MY_SESSION_ID=`/bin/ps h -o sess -p $$`
# get PID
/bin/ps hww -u "$JENKINS_USER" -o sess,ppid,pid,cmd | \
while read sess ppid pid cmd; do
[ "$ppid" = 1 ] || continue
# this test doesn't work because Jenkins sets a new Session ID
# [ "$sess" = "$MY_SESSION_ID" ] || continue
echo "$cmd" | grep $JENKINS_WAR > /dev/null
[ $? = 0 ] || continue
# found a PID
echo $pid > "$JENKINS_PID_FILE"
done
touch $JENKINS_LOCKFILE
else
failure
fi
echo
;;

Answer 1

Oh, I found the answer. These are the functions defined in /etc/init.d/functions.
# Log that something succeeded
success() {
[ "$BOOTUP" != "verbose" -a -z "${LSB:-}" ] && echo_success
return 0
}
# Log that something failed
failure() {
local rc=$?
[ "$BOOTUP" != "verbose" -a -z "${LSB:-}" ] && echo_failure
[ -x /bin/plymouth ] && /bin/plymouth --details
return $rc
}