Get Help About Commands

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 ?. You do not need to press Enter after typing the question mark. What you see on the screen depends on when and where you type the question mark:

• If you type the question mark at the command-line prompt, the CLI lists the available commands and options.
• If you type the 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.
• If you type the 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.

Examples: Get Help with Commands

In this example, all available commands are listed at the top level of the command hierarchy:

user@host> ?

Possible completions:

  clear                            Clear information in the system

  configure                            Manipulate software configuration information

  file                            Perform file operations

  help                            Provide help information

  monitor                            Real-time debugging

  mtrace                            Trace multicast path from a source to a receiver

  ping                            Ping a remote target

  quit                            Exit the management session

  request                            Make system-level requests

  restart                            Restart a software process

  set                            Set CLI properties, date, time, craft display text

  show                            Show information about the system

  ssh                            Open a secure shell to another host

  start                            Start a software process

  telnet                            Telnet to another host

  test                            Diagnostic debugging commands

  traceroute                            Trace the route to a remote host

user@host>

List all commands that start with the letter c:

user@host> c?

Possible completions:

  clear                            Clear information in the system

  configure                            Manipulate software configuration information

user@host> c

List all available clear commands:

user@host> clear ? 

Possible completions:

  arp                                              Clear address-resolution information

  bgp                                              Clear BGP information

  chassis                             Clear chassis information

  firewall                             Clear firewall counters

  igmp                             Clear IGMP information

  interfaces                             Clear interface information

  isis                             Clear IS-IS information

  ldp                             Clear LDP information

  log                             Clear contents of a log file

  mpls                 Clear MPLS information

  msdp                             Clear MSDP information

  multicast                             Clear Multicast information

  ospf                             Clear OSPF information

  pim                             Clear PIM information

  rip                             Clear RIP information

  route                             Clear routing table information

  rsvp                             Clear RSVP information

  snmp                             Clear SNMP information

  system                             Clear system status

  vrrp                             Clear VRRP statistics information

user@host> clear