Cisco CLI Tips and Tricks

1. Key shortcuts

Key Combination Result
Recalling Commands
Ctrl+P or UP Moves backwards through command history
Ctrl+N or DOWN Moves forward through command history
Moving Cursor
Ctrl+B or LEFT Moves 1 character to the left (Backward)
Ctrl+F or RIGHT Moves 1 character to the right (Forward)
ESC,B Moves 1 word to the left (Backward)
ESC,F Moves 1 word to the right (Forward)
Ctrl+A Moves to the beginning of the line
Ctrl+E Moves to the end of the line
Deleting Entries
DEL or BACKSPACE Deletes one character to the left of the cursor
Ctrl+D Deletes the character at the cursor
Ctrl+K Deletes all the characters from the cursor to the end of the command line
Ctrl+U or Ctrl+X Deletes all the characters from the beginning of the line to the cursor
Ctrl+W Deletes the word to the left of the cursor
ESC,D Deletes from the cursor to the end of the word
Recalling Deleted Entries
Ctrl+Y Recalls the most recent characters deleted with Ctrl+X, Ctrl+K or Ctrl+U
ESC,Y After recalling with Ctrl+Y, browse through the history of deleted characters
Redisplay the current line
Ctrl+L or Ctrl+R Redisplays the current command line. – Useful when interrupted by logs
Transposing
Ctrl+T Transposes the character to the left of the cursor with the character to the right
Capitalization
ESC,C Capitalizes the letter at the cursor
ESC,L Changes the word at the cursor to lowercase
ESC,U Changes the word at the cursor to uppercase
Disable editing commands temporarily
Ctrl+V or ESC,Q Make the system accept the following key as a command, not asa an editing command – Useful for inserting “?” into the command

2. Limiting Output

When running a show command you can limit the output by only showing the lines that begin with, include or do not include a certain Regular Expression:

R# show COMMAND | {being|include|exclude} REGEX

When the output is long enough to generate a -More- line, you can filter the output using :

-More-
/REGEX
! Goes to the first match of Regular Expression
-REGEX
! Displays lines that do not contain the Regular Expression
+REGEX
! Displays lines that contain the Regular Expression

2.1 Regular Expressions

Regular expressions define patterns of characters that are used to match lines in a text entry. Usually a character in the REGEX matches itself in a string, but there are some special characters or groups of characters that don’t match themselves:

Character Meaning
. Matches a single character, including space
_ Matches: , { } ( _ space beginning-of-string end-of-string
\ Escape character used to match a special character
Groups
[LIST] Matches any character in the LIST. The LIST can be specified as an unordered group of characters and ranges, like a-dA-D
[^LIST] Matches any character that is not part of the LIST.

A pattern can be a character or a group of characters between parenthesis (). Between parenthesis, a | acts as a logical OR. Patterns can be multiplied if followed by one of the Multiplier characters. Also, you can recall a pattern used once, if you use a \ followed by the number which indicates which pattern it is.

Patterns
(PATTERN) Matches the PATTERN
(PATTERN1|PATTERN2) Matches PATTERN1 or PATTERN2
Multipliers
* Matches 0 or more sequences of the pattern
+ Matches 1 or more sequences of the pattern
? Matches 0 or 1 sequences of the pattern
^ Matches the beginning of string
$ Matches end of the string
Recalling
\n Recalls the n-th pattern and uses it again in the regular expression

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