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1 | @ignore |
2 | This file documents the user interface to the GNU History library. | |
3 | ||
4 | Copyright (C) 1988, 1991, 1996 Free Software Foundation, Inc. | |
5 | Authored by Brian Fox and Chet Ramey. | |
6 | ||
7 | Permission is granted to make and distribute verbatim copies of this manual | |
8 | provided the copyright notice and this permission notice are preserved on | |
9 | all copies. | |
10 | ||
11 | Permission is granted to process this file through Tex and print the | |
12 | results, provided the printed document carries copying permission notice | |
13 | identical to this one except for the removal of this paragraph (this | |
14 | paragraph not being relevant to the printed manual). | |
15 | ||
16 | Permission is granted to copy and distribute modified versions of this | |
17 | manual under the conditions for verbatim copying, provided also that the | |
18 | GNU Copyright statement is available to the distributee, and provided that | |
19 | the entire resulting derived work is distributed under the terms of a | |
20 | permission notice identical to this one. | |
21 | ||
22 | Permission is granted to copy and distribute translations of this manual | |
23 | into another language, under the above conditions for modified versions. | |
24 | @end ignore | |
25 | ||
26 | @node Using History Interactively | |
27 | @chapter Using History Interactively | |
28 | ||
29 | @ifset BashFeatures | |
30 | This chapter describes how to use the GNU History Library interactively, | |
31 | from a user's standpoint. It should be considered a user's guide. For | |
32 | information on using the GNU History Library in other programs, | |
33 | see the GNU Readline Library Manual. | |
34 | @end ifset | |
35 | @ifclear BashFeatures | |
36 | This chapter describes how to use the GNU History Library interactively, | |
37 | from a user's standpoint. It should be considered a user's guide. For | |
38 | information on using the GNU History Library in your own programs, | |
39 | @pxref{Programming with GNU History}. | |
40 | @end ifclear | |
41 | ||
42 | @ifset BashFeatures | |
43 | @menu | |
44 | * Bash History Facilities:: How Bash lets you manipulate your command | |
45 | history. | |
46 | * Bash History Builtins:: The Bash builtin commands that manipulate | |
47 | the command history. | |
48 | * History Interaction:: What it feels like using History as a user. | |
49 | @end menu | |
50 | @end ifset | |
51 | @ifclear BashFeatures | |
52 | @menu | |
53 | * History Interaction:: What it feels like using History as a user. | |
54 | @end menu | |
55 | @end ifclear | |
56 | ||
57 | @ifset BashFeatures | |
58 | @node Bash History Facilities | |
59 | @section Bash History Facilities | |
60 | @cindex command history | |
61 | @cindex history list | |
62 | ||
63 | When the @samp{-o history} option to the @code{set} builtin | |
64 | is enabled (@pxref{The Set Builtin}), | |
65 | the shell provides access to the @var{command history}, | |
66 | the list of commands previously typed. The text of the last | |
67 | @code{HISTSIZE} | |
68 | commands (default 500) is saved in a history list. The shell | |
69 | stores each command in the history list prior to parameter and | |
70 | variable expansion | |
71 | but after history expansion is performed, subject to the | |
72 | values of the shell variables | |
73 | @code{HISTIGNORE} and @code{HISTCONTROL}. | |
74 | When the shell starts up, the history is initialized from the | |
75 | file named by the @code{HISTFILE} variable (default @file{~/.bash_history}). | |
76 | @code{HISTFILE} is truncated, if necessary, to contain no more than | |
77 | the number of lines specified by the value of the @code{HISTFILESIZE} | |
78 | variable. When an interactive shell exits, the last | |
79 | @code{HISTSIZE} lines are copied from the history list to @code{HISTFILE}. | |
80 | If the @code{histappend} shell option is set (@pxref{Bash Builtins}), | |
81 | the lines are appended to the history file, | |
82 | otherwise the history file is overwritten. | |
83 | If @code{HISTFILE} | |
84 | is unset, or if the history file is unwritable, the history is | |
85 | not saved. After saving the history, the history file is truncated | |
86 | to contain no more than @code{$HISTFILESIZE} | |
87 | lines. If @code{HISTFILESIZE} is not set, no truncation is performed. | |
88 | ||
89 | The builtin command @code{fc} may be used to list or edit and re-execute | |
90 | a portion of the history list. | |
91 | The @code{history} builtin can be used to display or modify the history | |
92 | list and manipulate the history file. | |
93 | When using the command-line editing, search commands | |
94 | are available in each editing mode that provide access to the | |
95 | history list. | |
96 | ||
97 | The shell allows control over which commands are saved on the history | |
98 | list. The @code{HISTCONTROL} and @code{HISTIGNORE} | |
99 | variables may be set to cause the shell to save only a subset of the | |
100 | commands entered. | |
101 | The @code{cmdhist} | |
102 | shell option, if enabled, causes the shell to attempt to save each | |
103 | line of a multi-line command in the same history entry, adding | |
104 | semicolons where necessary to preserve syntactic correctness. | |
105 | The @code{lithist} | |
106 | shell option causes the shell to save the command with embedded newlines | |
107 | instead of semicolons. | |
108 | @xref{Bash Builtins}, for a description of @code{shopt}. | |
109 | ||
110 | @node Bash History Builtins | |
111 | @section Bash History Builtins | |
112 | @cindex history builtins | |
113 | ||
114 | Bash provides two builtin commands that allow you to manipulate the | |
115 | history list and history file. | |
116 | ||
117 | @table @code | |
118 | ||
119 | @item fc | |
d1857004 | 120 | @comment btindex fc |
d60d9f65 SS |
121 | @example |
122 | @code{fc [-e @var{ename}] [-nlr] [@var{first}] [@var{last}]} | |
123 | @code{fc -s [@var{pat}=@var{rep}] [@var{command}]} | |
124 | @end example | |
125 | ||
126 | Fix Command. In the first form, a range of commands from @var{first} to | |
127 | @var{last} is selected from the history list. Both @var{first} and | |
128 | @var{last} may be specified as a string (to locate the most recent | |
129 | command beginning with that string) or as a number (an index into the | |
130 | history list, where a negative number is used as an offset from the | |
131 | current command number). If @var{last} is not specified it is set to | |
132 | @var{first}. If @var{first} is not specified it is set to the previous | |
133 | command for editing and @minus{}16 for listing. If the @samp{-l} flag is | |
134 | given, the commands are listed on standard output. The @samp{-n} flag | |
135 | suppresses the command numbers when listing. The @samp{-r} flag | |
136 | reverses the order of the listing. Otherwise, the editor given by | |
137 | @var{ename} is invoked on a file containing those commands. If | |
138 | @var{ename} is not given, the value of the following variable expansion | |
139 | is used: @code{$@{FCEDIT:-$@{EDITOR:-vi@}@}}. This says to use the | |
140 | value of the @code{FCEDIT} variable if set, or the value of the | |
141 | @code{EDITOR} variable if that is set, or @code{vi} if neither is set. | |
142 | When editing is complete, the edited commands are echoed and executed. | |
143 | ||
144 | In the second form, @var{command} is re-executed after each instance | |
145 | of @var{pat} in the selected command is replaced by @var{rep}. | |
146 | ||
147 | A useful alias to use with the @code{fc} command is @code{r='fc -s'}, so | |
148 | that typing @samp{r cc} runs the last command beginning with @code{cc} | |
149 | and typing @samp{r} re-executes the last command (@pxref{Aliases}). | |
150 | ||
151 | @item history | |
d1857004 | 152 | @comment btindex history |
d60d9f65 SS |
153 | @example |
154 | history [-c] [@var{n}] | |
155 | history [-anrw] [@var{filename}] | |
156 | history -ps @var{arg} | |
157 | @end example | |
158 | ||
159 | Display the history list with line numbers. Lines prefixed with | |
160 | with a @samp{*} have been modified. An argument of @var{n} says | |
161 | to list only the last @var{n} lines. Options, if supplied, have | |
162 | the following meanings: | |
163 | ||
164 | @table @code | |
165 | @item -w | |
166 | Write out the current history to the history file. | |
167 | ||
168 | @item -r | |
169 | Read the current history file and append its contents to | |
170 | the history list. | |
171 | ||
172 | @item -a | |
173 | Append the new | |
174 | history lines (history lines entered since the beginning of the | |
175 | current Bash session) to the history file. | |
176 | ||
177 | @item -n | |
178 | Append the history lines not already read from the history file | |
179 | to the current history list. These are lines appended to the history | |
180 | file since the beginning of the current Bash session. | |
181 | ||
182 | @item -c | |
183 | Clear the history list. This may be combined | |
184 | with the other options to replace the history list completely. | |
185 | ||
186 | @item -s | |
187 | The @var{arg}s are added to the end of | |
188 | the history list as a single entry. | |
189 | ||
190 | @item -p | |
191 | Perform history substitution on the @var{arg}s and display the result | |
192 | on the standard output, without storing the results in the history list. | |
193 | @end table | |
194 | ||
195 | When the @samp{-w}, @samp{-r}, @samp{-a}, or @samp{-n} option is | |
196 | used, if @var{filename} | |
197 | is given, then it is used as the history file. If not, then | |
198 | the value of the @code{HISTFILE} variable is used. | |
199 | ||
200 | @end table | |
201 | @end ifset | |
202 | ||
203 | @node History Interaction | |
204 | @section History Expansion | |
205 | @cindex history expansion | |
206 | ||
207 | The History library provides a history expansion feature that is similar | |
208 | to the history expansion provided by @code{csh}. This section | |
209 | describes the syntax used to manipulate the history information. | |
210 | ||
211 | History expansions introduce words from the history list into | |
212 | the input stream, making it easy to repeat commands, insert the | |
213 | arguments to a previous command into the current input line, or | |
214 | fix errors in previous commands quickly. | |
215 | ||
216 | History expansion takes place in two parts. The first is to determine | |
217 | which line from the history list should be used during substitution. | |
218 | The second is to select portions of that line for inclusion into the | |
219 | current one. The line selected from the history is called the | |
220 | @dfn{event}, and the portions of that line that are acted upon are | |
221 | called @dfn{words}. Various @dfn{modifiers} are available to manipulate | |
222 | the selected words. The line is broken into words in the same fashion | |
223 | that Bash does, so that several words | |
224 | surrounded by quotes are considered one word. | |
225 | History expansions are introduced by the appearance of the | |
226 | history expansion character, which is @samp{!} by default. | |
227 | @ifset BashFeatures | |
228 | Only @samp{\} and @samp{'} may be used to escape the history expansion | |
229 | character. | |
230 | @end ifset | |
231 | ||
232 | @ifset BashFeatures | |
233 | Several shell options settable with the @code{shopt} | |
234 | builtin (@pxref{Bash Builtins}) may be used to tailor | |
235 | the behavior of history expansion. If the | |
236 | @code{histverify} shell option is enabled, and Readline | |
237 | is being used, history substitutions are not immediately passed to | |
238 | the shell parser. | |
239 | Instead, the expanded line is reloaded into the Readline | |
240 | editing buffer for further modification. | |
241 | If Readline is being used, and the @code{histreedit} | |
242 | shell option is enabled, a failed history expansion will be | |
243 | reloaded into the Readline editing buffer for correction. | |
244 | The @samp{-p} option to the @code{history} builtin command | |
245 | may be used to see what a history expansion will do before using it. | |
246 | The @samp{-s} option to the @code{history} builtin may be used to | |
247 | add commands to the end of the history list without actually executing | |
248 | them, so that they are available for subsequent recall. | |
249 | This is most useful in conjunction with Readline. | |
250 | ||
251 | The shell allows control of the various characters used by the | |
252 | history expansion mechanism with the @code{histchars} variable. | |
253 | @end ifset | |
254 | ||
255 | @menu | |
256 | * Event Designators:: How to specify which history line to use. | |
257 | * Word Designators:: Specifying which words are of interest. | |
258 | * Modifiers:: Modifying the results of substitution. | |
259 | @end menu | |
260 | ||
261 | @node Event Designators | |
262 | @subsection Event Designators | |
263 | @cindex event designators | |
264 | ||
265 | An event designator is a reference to a command line entry in the | |
266 | history list. | |
267 | @cindex history events | |
268 | ||
269 | @table @asis | |
270 | ||
271 | @item @code{!} | |
272 | Start a history substitution, except when followed by a space, tab, | |
273 | the end of the line, @samp{=} or @samp{(}. | |
274 | ||
275 | @item @code{!@var{n}} | |
276 | Refer to command line @var{n}. | |
277 | ||
278 | @item @code{!-@var{n}} | |
279 | Refer to the command @var{n} lines back. | |
280 | ||
281 | @item @code{!!} | |
282 | Refer to the previous command. This is a synonym for @samp{!-1}. | |
283 | ||
284 | @item @code{!@var{string}} | |
285 | Refer to the most recent command starting with @var{string}. | |
286 | ||
287 | @item @code{!?@var{string}[?]} | |
288 | Refer to the most recent command containing @var{string}. The trailing | |
289 | @samp{?} may be omitted if the @var{string} is followed immediately by | |
290 | a newline. | |
291 | ||
292 | @item @code{^@var{string1}^@var{string2}^} | |
293 | Quick Substitution. Repeat the last command, replacing @var{string1} | |
294 | with @var{string2}. Equivalent to | |
295 | @code{!!:s/@var{string1}/@var{string2}/}. | |
296 | ||
297 | @item @code{!#} | |
298 | The entire command line typed so far. | |
299 | ||
300 | @end table | |
301 | ||
302 | @node Word Designators | |
303 | @subsection Word Designators | |
304 | ||
305 | Word designators are used to select desired words from the event. | |
306 | A @samp{:} separates the event specification from the word designator. It | |
307 | may be omitted if the word designator begins with a @samp{^}, @samp{$}, | |
308 | @samp{*}, @samp{-}, or @samp{%}. Words are numbered from the beginning | |
309 | of the line, with the first word being denoted by 0 (zero). Words are | |
310 | inserted into the current line separated by single spaces. | |
311 | ||
312 | @table @code | |
313 | ||
314 | @item 0 (zero) | |
315 | The @code{0}th word. For many applications, this is the command word. | |
316 | ||
317 | @item @var{n} | |
318 | The @var{n}th word. | |
319 | ||
320 | @item ^ | |
321 | The first argument; that is, word 1. | |
322 | ||
323 | @item $ | |
324 | The last argument. | |
325 | ||
326 | @item % | |
327 | The word matched by the most recent @samp{?@var{string}?} search. | |
328 | ||
329 | @item @var{x}-@var{y} | |
330 | A range of words; @samp{-@var{y}} abbreviates @samp{0-@var{y}}. | |
331 | ||
332 | @item * | |
333 | All of the words, except the @code{0}th. This is a synonym for @samp{1-$}. | |
334 | It is not an error to use @samp{*} if there is just one word in the event; | |
335 | the empty string is returned in that case. | |
336 | ||
337 | @item @var{x}* | |
338 | Abbreviates @samp{@var{x}-$} | |
339 | ||
340 | @item @var{x}- | |
341 | Abbreviates @samp{@var{x}-$} like @samp{@var{x}*}, but omits the last word. | |
342 | ||
343 | @end table | |
344 | ||
345 | If a word designator is supplied without an event specification, the | |
346 | previous command is used as the event. | |
347 | ||
348 | @node Modifiers | |
349 | @subsection Modifiers | |
350 | ||
351 | After the optional word designator, you can add a sequence of one or more | |
352 | of the following modifiers, each preceded by a @samp{:}. | |
353 | ||
354 | @table @code | |
355 | ||
356 | @item h | |
357 | Remove a trailing pathname component, leaving only the head. | |
358 | ||
359 | @item t | |
360 | Remove all leading pathname components, leaving the tail. | |
361 | ||
362 | @item r | |
363 | Remove a trailing suffix of the form @samp{.@var{suffix}}, leaving | |
364 | the basename. | |
365 | ||
366 | @item e | |
367 | Remove all but the trailing suffix. | |
368 | ||
369 | @item p | |
370 | Print the new command but do not execute it. | |
371 | ||
372 | @ifset BashFeatures | |
373 | @item q | |
374 | Quote the substituted words, escaping further substitutions. | |
375 | ||
376 | @item x | |
377 | Quote the substituted words as with @samp{q}, | |
378 | but break into words at spaces, tabs, and newlines. | |
379 | @end ifset | |
380 | ||
381 | @item s/@var{old}/@var{new}/ | |
382 | Substitute @var{new} for the first occurrence of @var{old} in the | |
383 | event line. Any delimiter may be used in place of @samp{/}. | |
384 | The delimiter may be quoted in @var{old} and @var{new} | |
385 | with a single backslash. If @samp{&} appears in @var{new}, | |
386 | it is replaced by @var{old}. A single backslash will quote | |
387 | the @samp{&}. The final delimiter is optional if it is the last | |
388 | character on the input line. | |
389 | ||
390 | @item & | |
391 | Repeat the previous substitution. | |
392 | ||
393 | @item g | |
394 | Cause changes to be applied over the entire event line. Used in | |
395 | conjunction with @samp{s}, as in @code{gs/@var{old}/@var{new}/}, | |
396 | or with @samp{&}. | |
397 | ||
398 | @end table |