[Issue 3409] Support '--help' option of Pulsar command-line tools (#3410)

* Support '--help' option of Pulsar command-line tools.

* Fix a indentation

* Fix a minor bug

bin/bookkeeper

@@ -195,7 +195,7 @@ elif [ $COMMAND == "upgrade" ]; then
 elif [ $COMMAND == "shell" ]; then
     ENTRY_FORMATTER_ARG="-DentryFormatterClass=${ENTRY_FORMATTER_CLASS:-org.apache.bookkeeper.util.StringEntryFormatter}"
     exec $JAVA $OPTS $ENTRY_FORMATTER_ARG org.apache.bookkeeper.bookie.BookieShell -conf $BOOKIE_CONF $@
-elif [ $COMMAND == "help" ]; then
+elif [ $COMMAND == "help" -o $COMMAND == "--help" -o $COMMAND == "-h" ]; then
     bookkeeper_help;
 else
     exec $JAVA $OPTS $COMMAND $@

bin/pulsar

@@ -334,7 +334,7 @@ elif [ $COMMAND == "sql-worker" ]; then
     exec ${PRESTO_HOME}/bin/launcher --etc-dir ${PULSAR_PRESTO_CONF} "${@}"
 elif [ $COMMAND == "tokens" ]; then
       exec $JAVA $OPTS org.apache.pulsar.utils.auth.tokens.TokensCliUtils $@
-elif [ $COMMAND == "help" ]; then
+elif [ $COMMAND == "help" -o $COMMAND == "--help" -o $COMMAND == "-h" ]; then
     pulsar_help;
 else
     echo ""

bin/pulsar-daemon

@@ -50,11 +50,18 @@ PULSAR_LOG_APPENDER=${PULSAR_LOG_APPENDER:-"RollingFile"}
 PULSAR_STOP_TIMEOUT=${PULSAR_STOP_TIMEOUT:-30}
 PULSAR_PID_DIR=${PULSAR_PID_DIR:-$PULSAR_HOME/bin}
 
-if [ $# -lt 2 ]
-then
-    echo "Error: no enough arguments provided."
+if [ $# = 0 ]; then
     usage
     exit 1
+elif [ $# = 1 ]; then
+    if [ $1 == "--help" -o $1 == "-h" ]; then
+        usage
+        exit 1
+    else
+        echo "Error: no enough arguments provided."
+        usage
+        exit 1
+    fi
 fi
 
 startStop=$1

bin/pulsar-perf

@@ -74,7 +74,7 @@ add_maven_deps_to_classpath() {
 }
 pulsar_help() {
     cat <<EOF
-Usage: pulsar <command>
+Usage: pulsar-perf <command>
 where command is one of:
     produce                 Run a producer
     consume                 Run a consumer
@@ -87,13 +87,13 @@ where command is one of:
     simulation-client       Run a simulation server acting as a Pulsar client
     simulation-controller   Run a simulation controller to give commands to servers
 
-    help                           This help message
+    help                    This help message
 
 or command is the full name of a class with a defined main() method.
 
 Environment variables:
    PULSAR_LOG_CONF               Log4j configuration file (default $DEFAULT_LOG_CONF)
-   PULSAR_CLIENT_CONF          Configuration file for client (default: $DEFAULT_CLIENT_CONF)
+   PULSAR_CLIENT_CONF            Configuration file for client (default: $DEFAULT_CLIENT_CONF)
    PULSAR_EXTRA_OPTS             Extra options to be passed to the jvm
    PULSAR_EXTRA_CLASSPATH        Add extra paths to the pulsar classpath