You can display commands and syntax information in any mode and from any point in the command hierarchy.
Enter a question mark (?) in any command mode to display the list of commands available in that mode.
device# ?
To display a list of commands that start with the same characters, type the characters followed by a question mark (? ).
device# e? Possible completions: event-handler Event Handler Commands execute-script Run user-level BASH scripts exit Exit the management session
To display the keywords and arguments associated with a command, enter the keyword followed by a space a then a question mark (?).
device# terminal ? Possible completions: length Sets Terminal Length for this session monitor Enables terminal monitoring for this session no Sets Terminal Length for this session to default :24. timeout Sets the interval that the EXEC command interpreter wait for user input.
If the question mark (?) is typed within an incomplete keyword, but the keyword matches several keywords, the CLI displays help for all the matching keywords.
device# show d? Possible completions: debug Display the udld debug configuration defaults Display default configuration dot1x Show dot1x
If the device does not recognize a command after you press Enter, an error message displays.
device# hookup
^
syntax error: unknown argument.
If you enter an incomplete command, an error message displays.
device# show
^
syntax error: unknown argument.