Online Help

The CLI provides context-sensitive help at every level of the command hierarchy. The help information tells you which commands are available at the current level in the hierarchy and provides a brief description of each.

To get help while in the CLI, type a question mark (?) in one of the following ways:

• Type a question mark at the command-line prompt—The CLI lists the available commands and options. For examples, see CLI Operational Mode and CLI Configuration Mode.
• Type a question mark after entering the complete name of a command or command option—The CLI lists the available commands and options, then redisplays the command names and options that you typed:
  user@host> request ?

  Possible completions:
    chassis              Perform chassis-specific operations
    ipsec                Perform IP Security operations
    message              Send text message to other users
    routing-engine       Log in to Routing Engine
    security             Perform security-level operations
    services             Perform service application operations
    support              Perform JUNOS support tasks
    system               Perform system-level operations
  user@host> request

• Type a question mark in the middle of a command name—The CLI lists possible command completions that match the letters you have entered so far, then redisplays the letters that you typed. For example, to list all operational mode commands that start with the letter s, type the following:
  user@host> s?

  Possible completions:
    set                  Set CLI properties, date/time, craft interface message
    show                 Show system information
    ssh                  Start secure shell on another host
    start                Start shell
  user@host> s

The CLI also provides usage guidelines and summary information for text contained in configuration statements if you enter the help topic and help reference commands. For example, to display usage guidelines for the OSPF hello interval, enter the command help topic ospf hello-interval. You can enter help commands in operational or configuration mode.