Getting 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: Getting 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

  bfd               Clear Bidirectional Forwarding Detection information

  bgp               Clear Border Gateway Protocol information

  cli               Clear command-line interface settings

  firewall          Clear firewall counters

  helper            Clear port-forwarding helper information

  igmp              Clear Internet Group Management Protocol information

  ike               Clear IKE information

  ilmi              Clear interim local management interface statistics

  interfaces        Clear interface information

  ipsec             Clear IP Security information

  ipv6              Clear IP version 6 information

  isis              Clear Intermediate System-to-Intermediate System information

  ldp               Clear Label Distribution Protocol information

  log               Clear contents of log file

  mld               Clear multicast listener discovery information

  mpls              Clear Multiprotocol Label Switching information

  msdp              Clear Multicast Source Discovery Protocol information

  multicast         Clear multicast information

  ospf              Clear Open Shortest Path First information

  ospf3             Clear Open Shortest Path First version 3 information

  pgm               Clear Pragmatic Generalized Multicast information

  pim               Clear Protocol Independent Multicast information

  rip               Clear Routing Information Protocol information

  ripng             Clear Routing Information Protocol for IPv6 information

  route             Clear routing table information

  rsvp              Clear Resource Reservation Protocol information

  services          Clear service applications information

  snmp              Clear Simple Network Management Protocol information

  system            Clear system information

  vpls              Clear VPLS information

  vrrp              Clear Virtual Router Redundancy Protocol statistics

user@host> clear