This document describes the GNU History library, a programming tool that provides a consistent user interface for recalling lines of previously typed input.
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Copyright (C) 1989, 1991 Free Software Foundation, Inc.
This chapter describes how to use the GNU History Library interactively, from a user's standpoint. It should be considered a user's guide. For information on using the GNU History Library in your own programs, see section Programming with GNU History.
The History library provides a history expansion feature that is similar
to the history expansion provided by
csh. The following text
describes the syntax used to manipulate the history information.
History expansion takes place in two parts. The first is to determine which line from the previous history 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 previous history is called the event, and the portions of that line that are acted upon are called words. The line is broken into words in the same fashion that Bash does, so that several English (or Unix) words surrounded by quotes are considered as one word.
An event designator is a reference to a command line entry in the history list.
A : separates the event specification from the word designator. It can be omitted if the word designator begins with a ^, $, * or %. Words are numbered from the beginning of the line, with the first word being denoted by a 0 (zero).
0th word. For many applications, this is the command word.
0th. This is a synonym for
1-$. 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*, but omits the last word.
After the optional word designator, you can add a sequence of one or more of the following modifiers, each preceded by a :.
s, as in
gs/old/new/, or with