Cisco Systems 4500 Performing History Substitution, About Cisco IOS Command Modes

2-4
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 2 Command-Line Interfaces
Performing History Substitution
Performing History Substitution
The history buffer stores the last 20 command lines you entered. History substitution enables you to
access these command lines without retyping them. Table 2-2 lists the history substitution commands.
About Cisco IOS Command Modes
Note For complete information about Cisco IOS command modes, refer to the Cisco IOS Configuration
Fundamentals Configuration Guide and the Cisco IOS Configuration Fundamentals Command
Reference at the following URLs:
http://www.cisco.com/en/US/docs/ios/12_2/configfun/configuration/guide/ffun_c.html
http://www.cisco.com/en/US/docs/ios/fundamentals/command/reference/cf_book.html
The Cisco IOS user interface has many different modes: user EXEC, privileged EXEC (enable), global
configuration, interface, subinterface, and protocol-specific. The commands available to you depend on
which mode you are in. To get a list of the commands in a given mode, enter a question mark (?) at the
system prompt. See the “Getting a List of Commands and Syntax” section on page 2-5 for more
information.
When you start a session on the switch, you begin in user mode, also called user EXEC mode. Only a
small subset of commands are available in EXEC mode. To have access to all commands, you must enter
privileged EXEC mode, also called enable mode. To access the privileged EXEC mode, you must enter
a password. When you are in the privileged EXEC mode, you can enter any EXEC command or access
global configuration mode. Most EXEC commands are one-time commands, such as show commands,
which display the current configuration status, and clear commands, which reset counters or interfaces.
The EXEC commands are not saved when the switch is rebooted.
The configuration modes allow you to make changes to the running configuration. If you save the
configuration, these commands are stored when you reboot the switch. You must start in global
configuration mode. From global configuration mode, you can enter interface configuration mode,
subinterface configuration mode, and a variety of protocol-specific modes.
Table 2-2 History Substitution Commands
Command Purpose
Ctrl-P or the Up Arrow key1
1. The Arrow keys function only on ANSI-compatible terminals such as VT100s.
Recalls commands in the history buffer, beginning with
the most recent command. Repeat the key sequence to
recall older commands successively.
Ctrl-N or the Down Arrow key1Returns to more recent commands in the history buffer
after commands have been recalled with Ctrl-P or the
Up Arrow key. Repeat the key sequence to recall more
recent commands.
Switch# show history Lists the last several commands you have entered in
EXEC mode.