Info: (bash) History Interaction

bash: History Interaction

 
 9.3 History Expansion
 =====================
 
 The History library provides a history expansion feature that is similar
 to the history expansion provided by 'csh'.  This section describes the
 syntax used to manipulate the history information.
 
    History expansions introduce words from the history list into the
 input stream, making it easy to repeat commands, insert the arguments to
 a previous command into the current input line, or fix errors in
 previous commands quickly.
 
    History expansion is performed immediately after a complete line is
 read, before the shell breaks it into words.
 
    History expansion takes place in two parts.  The first is to
 determine which line from the history list should be used during
 substitution.  The second is to select portions of that line for
 inclusion into the current one.  The line selected from the history is
 called the "event", and the portions of that line that are acted upon
 are called "words".  Various "modifiers" are available to manipulate the
 selected words.  The line is broken into words in the same fashion that
 Bash does, so that several words surrounded by quotes are considered one
 word.  History expansions are introduced by the appearance of the
 history expansion character, which is '!' by default.  Only '\' and '''
 may be used to escape the history expansion character, but the history
 expansion character is also treated as quoted if it immediately precedes
 the closing double quote in a double-quoted string.
 
    Several shell options settable with the 'shopt' builtin (Bash
 Builtins) may be used to tailor the behavior of history expansion.  If
 the 'histverify' shell option is enabled, and Readline is being used,
 history substitutions are not immediately passed to the shell parser.
 Instead, the expanded line is reloaded into the Readline editing buffer
 for further modification.  If Readline is being used, and the
 'histreedit' shell option is enabled, a failed history expansion will be
 reloaded into the Readline editing buffer for correction.  The '-p'
 option to the 'history' builtin command may be used to see what a
 history expansion will do before using it.  The '-s' option to the
 'history' builtin may be used to add commands to the end of the history
 list without actually executing them, so that they are available for
 subsequent recall.  This is most useful in conjunction with Readline.
 
    The shell allows control of the various characters used by the
 history expansion mechanism with the 'histchars' variable, as explained
 above (Bash Variables).  The shell uses the history comment
 character to mark history timestamps when writing the history file.
bash: History Interaction

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