Starting the Gremlin console

Starting the Gremlin console for an interactive environment.

Gremlin is the query language used to interact with DSE Graph. One method of inputting Gremlin code is to use the Gremlin console. The Gremlin console is a useful interactive environment for directly inputting Gremlin to create graph schema, load data, administer graph, and retrieve traversal results. The Gremlin Console is an interface to the Gremlin Server that can interact with DSE Graph.

Procedure

Start the Gremlin console using the dse command and passing the additional command gremlin-console:
```
bin/dse gremlin-console
```
```
         \,,,/
         (o o)
-----oOOo-(3)-oOOo-----
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
plugin activated: tinkerpop.tinkergraph
gremlin>
```
Three plugins are activated by default, as shown. The Gremlin Server, tinkerpop.server, is started so that commands can be issued to DSE Graph. The utilities plugin, tinkerpop.utilities, provides various functions, helper methods and imports of external classes that are useful in Gremlin console. TinkerGraph, an in-memory graph that is used as an intermediary for some graph operations is started with tinkerpop.tinkergraph. The Gremlin console automatically connects to the remote Gremlin Server.
Note: The Gremlin console packaged with DataStax Enterprise does not allow plugin installation like the Gremlin console packaged with Apache TinkerPop.

Gremlin console help can be displayed with the -h flag:

bin/dse gremlin-console -h

usage: gremlin.sh [options] [...]
  -C, --color                               Disable use of ANSI colors
  -D, --debug                               Enabled debug Console output
  -Q, --quiet                               Suppress superfluous Console
                                            output
  -V, --verbose                             Enable verbose Console output
  -e, --execute=SCRIPT ARG1 ARG2 ...        Execute the specified script
                                            (SCRIPT ARG1 ARG2 ...) and
                                            close the console on
                                            completion
  -h, --help                                Display this help message
  -i, --interactive=SCRIPT ARG1 ARG2 ...    Execute the specified script
                                            and leave the console open on
                                            completion
  -l                                        Set the logging level of
                                            components that use standard
                                            logging output independent of
                                            the Console
  -v, --version                             Display the version

Tip: Use -V to display all lines when loading a file, to discover which line of code causes an error.

Run the Gremlin console with the host:port option to specify a specific host and port:
```
bin/dse gremlin-console 127.0.0.1:8182
```
Any hostname or IP address will work to specify the host.
Run Gremlin console with the -e flag to execute one or more scripts:
```
bin/dse gremlin-console -e test1.groovy -e test2.groovy
```
If the scripts run successfully, the command will return with the prompt after execution. If errors occur, the standard output will show the errors.
If you prefer to have Gremlin console open at the script completion, run Gremlin console with the -i flag instead of the -e flag:
```
bin/dse gremlin-console -i test1.groovy -i test2.groovy
```
If the scripts run successfully, the command will return with the Gremlin console prompt after execution. If errors occur, the console will show the errors.

Discover all Gremlin console commands with help. Console commands are not Gremlin language commands, but rather commands issued to the Gremlin console for shell functionality. The Gremlin console is based on the Groovy shell.

:help

For information about Groovy, visit:
    http://groovy-lang.org 

Available commands:
  :help       (:h  ) Display this help message
  ?           (:?  ) Alias to: :help
  :exit       (:x  ) Exit the shell
  :quit       (:q  ) Alias to: :exit
  import      (:i  ) Import a class into the namespace
  :display    (:d  ) Display the current buffer
  :clear      (:c  ) Clear the buffer and reset the prompt counter.
  :show       (:S  ) Show variables, classes or imports
  :inspect    (:n  ) Inspect a variable or the last result with the GUI object browser
  :purge      (:p  ) Purge variables, classes, imports or preferences
  :edit       (:e  ) Edit the current buffer
  :load       (:l  ) Load a file or URL into the buffer
  .           (:.  ) Alias to: :load
  :save       (:s  ) Save the current buffer to a file
  :record     (:r  ) Record the current session to a file
  :history    (:H  ) Display, manage and recall edit-line history
  :alias      (:a  ) Create an alias
  :register   (:rc ) Registers a new command with the shell
  :doc        (:D  ) Opens a browser window displaying the doc for the argument
  :set        (:=  ) Set (or list) preferences
  :uninstall  (:-  ) Uninstall a Maven library and its dependencies from the Gremlin Console
  :install    (:+  ) Install a Maven library and its dependencies into the Gremlin Console
  :plugin     (:pin) Manage plugins for the Console
  :remote     (:rem) Define a remote connection
  :submit     (:>  ) Send a Gremlin script to Gremlin Server

For help on a specific command type:
    :help command

The Gremlin Console provides code help via auto-complete functionality, using the <TAB> key to trigger a list of possible options.

Note: :install and :plugin should not be used with DSE Graph. These commands will result in gremlin console errors.