Be Playful in Bash

HISTORY EXPANSION

Event Designators

An event designator is a reference to a command line entry in thehistory list.

!

Start a history substitution, except when followed by ablank,newline, carriage return, =or ( (when the extglob shell option is enabled usingthe shopt builtin).

!n

Refer to command linen.

!-n

Refer to the current command line minusn.

!!

Refer to the previous command. This is a synonym for `!-1'.

!string

Refer to the most recent command starting with string.

!?string[?]

Refer to the most recent command containingstring.The trailing ? may be omitted ifstringis followed immediately by a newline.

^string1^string2^

Quick substitution. Repeat the last command, replacingstring1withstring2.Equivalent to``!!:s/string1/string2/''(see Modifiers below).

!#

The entire command line typed so far.

Word Designators

Word designators are used to select desired words from the event.A :separates the event specification from the word designator.It may be omitted if the word designator begins with a^,$,*,-,or%.Words are numbered from the beginning of the line,with the first word being denoted by 0 (zero).Words are inserted into the current line separated by single spaces.

0 (zero)

The zeroth word. For the shell, this is the commandword.

n

The nth word.

^

The first argument. That is, word 1.

$

The last argument.

%

The word matched by the most recent `?string?' search.

x-y

A range of words; `-y' abbreviates `0-y'.

*

All of the words but the zeroth. This is a synonymfor `1-$'. It is not an error to use*if there is just oneword in the event; the empty string is returned in that case.

x*

Abbreviates x-$.

x-

Abbreviates x-$ like x*, but omits the last word.

If a word designator is supplied without an event specification, theprevious command is used as the event. 

 

Modifiers

After the optional word designator, there may appear a sequence ofone or more of the following modifiers, each preceded by a `:'.

 

h

Remove a trailing file name component, leaving only the head.

t

Remove all leading file name components, leaving the tail.

r

Remove a trailing suffix of the form .xxx, leaving thebasename.

e

Remove all but the trailing suffix.

p

Print the new command but do not execute it.

q

Quote the substituted words, escaping further substitutions.

x

Quote the substituted words as withq,but break into words atblanksand newlines.

s/old/new/

Substitutenewfor the first occurrence ofoldin the event line. Any delimiter can be used in place of /. Thefinal delimiter is optional if it is the last character of theevent line. The delimiter may be quoted inoldandnewwith a single backslash. If & appears innew,it is replaced byold.A single backslash will quote the &. Ifoldis null, it is set to the lastoldsubstituted, or, if no previous history substitutions took place,the laststringin a!?string[?]search.

&

Repeat the previous substitution.

g

Cause changes to be applied over the entire event line. This isused in conjunction with `:s' (e.g., `:gs/old/new/')or `:&'. If used with`:s', any delimiter can be usedin place of /, and the final delimiter is optionalif it is the last character of the event line.An a may be used as a synonym for g.

G

Apply the following `s' modifier once to each word in the event line.