from RPM

jenkins.sh

# Search usable Java. We do this because various reports indicated
# that /usr/bin/java may not always point to Java 1.5
# see http://www.nabble.com/guinea-pigs-wanted-----Hudson-RPM-for-RedHat-Linux-td25673707.html
for candidate in /etc/alternatives/java /usr/lib/jvm/java-1.6.0/bin/java /usr/lib/jvm/jre-1.6.0/bin/java /usr/lib/jvm/java-1.5.0/bin/java /usr/lib/jvm/jre-1.5.0/bin/java /usr/bin/java
do
  [ -x "$JENKINS_JAVA_CMD" ] && break
  JENKINS_JAVA_CMD="$candidate"
done

JAVA_CMD="$JENKINS_JAVA_CMD $JENKINS_JAVA_OPTIONS -DJENKINS_HOME=$JENKINS_HOME -jar $JENKINS_WAR"
PARAMS="--logfile=/var/log/jenkins/jenkins.log --webroot=/var/cache/jenkins/war --daemon"
[ -n "$JENKINS_PORT" ] && PARAMS="$PARAMS --httpPort=$JENKINS_PORT"
[ -n "$JENKINS_LISTEN_ADDRESS" ] && PARAMS="$PARAMS --httpListenAddress=$JENKINS_LISTEN_ADDRESS"
[ -n "$JENKINS_HTTPS_PORT" ] && PARAMS="$PARAMS --httpsPort=$JENKINS_HTTPS_PORT"
[ -n "$JENKINS_HTTPS_KEYSTORE" ] && PARAMS="$PARAMS --httpsKeyStore=$JENKINS_HTTPS_KEYSTORE"
[ -n "$JENKINS_HTTPS_KEYSTORE_PASSWORD" ] && PARAMS="$PARAMS --httpsKeyStorePassword='$JENKINS_HTTPS_KEYSTORE_PASSWORD'"
[ -n "$JENKINS_HTTPS_LISTEN_ADDRESS" ] && PARAMS="$PARAMS --httpsListenAddress=$JENKINS_HTTPS_LISTEN_ADDRESS"
[ -n "$JENKINS_AJP_PORT" ] && PARAMS="$PARAMS --ajp13Port=$JENKINS_AJP_PORT"
[ -n "$JENKINS_AJP_LISTEN_ADDRESS" ] && PARAMS="$PARAMS --ajp13ListenAddress=$JENKINS_AJP_LISTEN_ADDRESS"
[ -n "$JENKINS_DEBUG_LEVEL" ] && PARAMS="$PARAMS --debug=$JENKINS_DEBUG_LEVEL"
[ -n "$JENKINS_HANDLER_STARTUP" ] && PARAMS="$PARAMS --handlerCountStartup=$JENKINS_HANDLER_STARTUP"
[ -n "$JENKINS_HANDLER_MAX" ] && PARAMS="$PARAMS --handlerCountMax=$JENKINS_HANDLER_MAX"
[ -n "$JENKINS_HANDLER_IDLE" ] && PARAMS="$PARAMS --handlerCountMaxIdle=$JENKINS_HANDLER_IDLE"
[ -n "$JENKINS_ARGS" ] && PARAMS="$PARAMS $JENKINS_ARGS"

if [ "$JENKINS_ENABLE_ACCESS_LOG" = "yes" ]; then
    PARAMS="$PARAMS --accessLoggerClassName=winstone.accesslog.SimpleAccessLogger --simpleAccessLogger.format=combined --simpleAccessLogger.file=/var/log/jenkins/access_log"
fi