With no options, display the command history list with line numbers. Lines listed with a * have been modified. An argument of n lists only the last nfilename is supplied, it is used as the name of the history file; if not, the value of lines. If HISTFILE is used. Options, if supplied, have the following meanings:

-c

Clear the history list by deleting all the entries.

-d offset

Delete the history entry at position offset.

-a

Append the ``new'' history lines (history lines entered since the beginning of the current bash session) to the history file.

-n

Read the history lines not already read from the history file into the current history list. These are lines appended to the history file since the beginning of the current bash session.

-r

Read the contents of the history file and use them as the current history.

-w

Write the current history to the history file, overwriting the history file's contents.

-p

Perform history substitution on the following args and display the result on the standard output. Does not store the results in the history list. Each arg must be quoted to disable normal history expansion.

-s

Store the args in the history list as a single entry. The last command in the history list is removed before the args are added.

The return value is 0 unless an invalid option is encountered, an error occurs while reading or writing the history file, an invalid offset is supplied as an argument to -d, or the history expansion supplied as an argument to -p fails.

! Start a history substitution, except when followed by a space,
 tab, the end of the line, `=' or `('.

!n Refer to command line n.

!-n Refer to the command n lines back.

!! 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 containing string.
 The trailing `?' may be omitted if the string is followed
 immediately by a newline.

^string1^string2^ Quick Substitution. Repeat the last command, replacing string1
 with string2. Equivalent to !!:s/string1/string2/.

!# 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.

For example,

!! designates the preceding command. When you type this, the
preceding command is repeated in toto.

!!:$ designates the last argument of the preceding command.
This may be shortened to !$.

!fi:2 designates the second argument of the most recent command
starting with the letters fi.

Here are the word designators:

0 (zero) The 0th word. For many applications, this is the command word.

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, except the 0th. This is a synonym for `1-$'.
It is not an error to use `*' if there is just one word 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,
the previous command is used as the event.

Modifiers

After the optional word designator, you can add a sequence of one or more of the following modifiers, each preceded by a `:'.

h Remove a trailing pathname component, leaving only the head.

t Remove all leading pathname components, leaving the tail.

r Remove a trailing suffix of the form `.suffix', leaving the basename.

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 with `q', but break into words at
spaces, tabs, and newlines.

s/old/new/
Substitute new for the first occurrence of old in the event line.
Any delimiter may be used in place of `/'. The delimiter may be
quoted in old and new with a single backslash.
If `&' appears in new, it is replaced by old.
A single backslash will quote the `&'.
The final delimiter is optional if it is the last character on the input line.

& Repeat the previous substitution.

g Cause changes to be applied over the entire event line.
Used in conjunction with `s', as in gs/old/new/, or with `&'.