Commit | Line | Data |
---|---|---|
7be570e7 JM |
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. | |
38 | @c For | |
39 | @c information on using the GNU History Library in your own programs, | |
40 | @c @pxref{Programming with GNU History}. | |
41 | @end ifclear | |
42 | ||
43 | @ifset BashFeatures | |
44 | @menu | |
45 | * Bash History Facilities:: How Bash lets you manipulate your command | |
46 | history. | |
47 | * Bash History Builtins:: The Bash builtin commands that manipulate | |
48 | the command history. | |
49 | * History Interaction:: What it feels like using History as a user. | |
50 | @end menu | |
51 | @end ifset | |
52 | @ifclear BashFeatures | |
53 | @menu | |
54 | * History Interaction:: What it feels like using History as a user. | |
55 | @end menu | |
56 | @end ifclear | |
57 | ||
58 | @ifset BashFeatures | |
59 | @node Bash History Facilities | |
60 | @section Bash History Facilities | |
61 | @cindex command history | |
62 | @cindex history list | |
63 | ||
64 | When the @samp{-o history} option to the @code{set} builtin | |
65 | is enabled (@pxref{The Set Builtin}), | |
66 | the shell provides access to the @var{command history}, | |
67 | the list of commands previously typed. The text of the last | |
68 | @code{HISTSIZE} | |
69 | commands (default 500) is saved in a history list. The shell | |
70 | stores each command in the history list prior to parameter and | |
71 | variable expansion | |
72 | but after history expansion is performed, subject to the | |
73 | values of the shell variables | |
74 | @code{HISTIGNORE} and @code{HISTCONTROL}. | |
75 | When the shell starts up, the history is initialized from the | |
76 | file named by the @code{HISTFILE} variable (default @file{~/.bash_history}). | |
77 | @code{HISTFILE} is truncated, if necessary, to contain no more than | |
78 | the number of lines specified by the value of the @code{HISTFILESIZE} | |
79 | variable. When an interactive shell exits, the last | |
80 | @code{HISTSIZE} lines are copied from the history list to @code{HISTFILE}. | |
81 | If the @code{histappend} shell option is set (@pxref{Bash Builtins}), | |
82 | the lines are appended to the history file, | |
83 | otherwise the history file is overwritten. | |
84 | If @code{HISTFILE} | |
85 | is unset, or if the history file is unwritable, the history is | |
86 | not saved. After saving the history, the history file is truncated | |
87 | to contain no more than @code{$HISTFILESIZE} | |
88 | lines. If @code{HISTFILESIZE} is not set, no truncation is performed. | |
89 | ||
90 | The builtin command @code{fc} may be used to list or edit and re-execute | |
91 | a portion of the history list. | |
92 | The @code{history} builtin can be used to display or modify the history | |
93 | list and manipulate the history file. | |
94 | When using the command-line editing, search commands | |
95 | are available in each editing mode that provide access to the | |
96 | history list. | |
97 | ||
98 | The shell allows control over which commands are saved on the history | |
99 | list. The @code{HISTCONTROL} and @code{HISTIGNORE} | |
100 | variables may be set to cause the shell to save only a subset of the | |
101 | commands entered. | |
102 | The @code{cmdhist} | |
103 | shell option, if enabled, causes the shell to attempt to save each | |
104 | line of a multi-line command in the same history entry, adding | |
105 | semicolons where necessary to preserve syntactic correctness. | |
106 | The @code{lithist} | |
107 | shell option causes the shell to save the command with embedded newlines | |
108 | instead of semicolons. | |
109 | @xref{Bash Builtins}, for a description of @code{shopt}. | |
110 | ||
111 | @node Bash History Builtins | |
112 | @section Bash History Builtins | |
113 | @cindex history builtins | |
114 | ||
115 | Bash provides two builtin commands that allow you to manipulate the | |
116 | history list and history file. | |
117 | ||
118 | @table @code | |
119 | ||
120 | @item fc | |
121 | @c btindex fc | |
122 | @example | |
123 | @code{fc [-e @var{ename}] [-nlr] [@var{first}] [@var{last}]} | |
124 | @code{fc -s [@var{pat}=@var{rep}] [@var{command}]} | |
125 | @end example | |
126 | ||
127 | Fix Command. In the first form, a range of commands from @var{first} to | |
128 | @var{last} is selected from the history list. Both @var{first} and | |
129 | @var{last} may be specified as a string (to locate the most recent | |
130 | command beginning with that string) or as a number (an index into the | |
131 | history list, where a negative number is used as an offset from the | |
132 | current command number). If @var{last} is not specified it is set to | |
133 | @var{first}. If @var{first} is not specified it is set to the previous | |
134 | command for editing and @minus{}16 for listing. If the @samp{-l} flag is | |
135 | given, the commands are listed on standard output. The @samp{-n} flag | |
136 | suppresses the command numbers when listing. The @samp{-r} flag | |
137 | reverses the order of the listing. Otherwise, the editor given by | |
138 | @var{ename} is invoked on a file containing those commands. If | |
139 | @var{ename} is not given, the value of the following variable expansion | |
140 | is used: @code{$@{FCEDIT:-$@{EDITOR:-vi@}@}}. This says to use the | |
141 | value of the @code{FCEDIT} variable if set, or the value of the | |
142 | @code{EDITOR} variable if that is set, or @code{vi} if neither is set. | |
143 | When editing is complete, the edited commands are echoed and executed. | |
144 | ||
145 | In the second form, @var{command} is re-executed after each instance | |
146 | of @var{pat} in the selected command is replaced by @var{rep}. | |
147 | ||
148 | A useful alias to use with the @code{fc} command is @code{r='fc -s'}, so | |
149 | that typing @samp{r cc} runs the last command beginning with @code{cc} | |
150 | and typing @samp{r} re-executes the last command (@pxref{Aliases}). | |
151 | ||
152 | @item history | |
153 | @c btindex history | |
154 | @example | |
155 | history [-c] [@var{n}] | |
156 | history [-anrw] [@var{filename}] | |
157 | history -ps @var{arg} | |
158 | @end example | |
159 | ||
160 | Display the history list with line numbers. Lines prefixed with | |
161 | with a @samp{*} have been modified. An argument of @var{n} says | |
162 | to list only the last @var{n} lines. Options, if supplied, have | |
163 | the following meanings: | |
164 | ||
165 | @table @code | |
166 | @item -w | |
167 | Write out the current history to the history file. | |
168 | ||
169 | @item -r | |
170 | Read the current history file and append its contents to | |
171 | the history list. | |
172 | ||
173 | @item -a | |
174 | Append the new | |
175 | history lines (history lines entered since the beginning of the | |
176 | current Bash session) to the history file. | |
177 | ||
178 | @item -n | |
179 | Append the history lines not already read from the history file | |
180 | to the current history list. These are lines appended to the history | |
181 | file since the beginning of the current Bash session. | |
182 | ||
183 | @item -c | |
184 | Clear the history list. This may be combined | |
185 | with the other options to replace the history list completely. | |
186 | ||
187 | @item -s | |
188 | The @var{arg}s are added to the end of | |
189 | the history list as a single entry. | |
190 | ||
191 | @item -p | |
192 | Perform history substitution on the @var{arg}s and display the result | |
193 | on the standard output, without storing the results in the history list. | |
194 | @end table | |
195 | ||
196 | When the @samp{-w}, @samp{-r}, @samp{-a}, or @samp{-n} option is | |
197 | used, if @var{filename} | |
198 | is given, then it is used as the history file. If not, then | |
199 | the value of the @code{HISTFILE} variable is used. | |
200 | ||
201 | @end table | |
202 | @end ifset | |
203 | ||
204 | @node History Interaction | |
205 | @section History Expansion | |
206 | @cindex history expansion | |
207 | ||
208 | The History library provides a history expansion feature that is similar | |
209 | to the history expansion provided by @code{csh}. This section | |
210 | describes the syntax used to manipulate the history information. | |
211 | ||
212 | History expansions introduce words from the history list into | |
213 | the input stream, making it easy to repeat commands, insert the | |
214 | arguments to a previous command into the current input line, or | |
215 | fix errors in previous commands quickly. | |
216 | ||
217 | History expansion takes place in two parts. The first is to determine | |
218 | which line from the history list should be used during substitution. | |
219 | The second is to select portions of that line for inclusion into the | |
220 | current one. The line selected from the history is called the | |
221 | @dfn{event}, and the portions of that line that are acted upon are | |
222 | called @dfn{words}. Various @dfn{modifiers} are available to manipulate | |
223 | the selected words. The line is broken into words in the same fashion | |
224 | that Bash does, so that several words | |
225 | surrounded by quotes are considered one word. | |
226 | History expansions are introduced by the appearance of the | |
227 | history expansion character, which is @samp{!} by default. | |
228 | @ifset BashFeatures | |
229 | Only @samp{\} and @samp{'} may be used to escape the history expansion | |
230 | character. | |
231 | @end ifset | |
232 | ||
233 | @ifset BashFeatures | |
234 | Several shell options settable with the @code{shopt} | |
235 | builtin (@pxref{Bash Builtins}) may be used to tailor | |
236 | the behavior of history expansion. If the | |
237 | @code{histverify} shell option is enabled, and Readline | |
238 | is being used, history substitutions are not immediately passed to | |
239 | the shell parser. | |
240 | Instead, the expanded line is reloaded into the Readline | |
241 | editing buffer for further modification. | |
242 | If Readline is being used, and the @code{histreedit} | |
243 | shell option is enabled, a failed history expansion will be | |
244 | reloaded into the Readline editing buffer for correction. | |
245 | The @samp{-p} option to the @code{history} builtin command | |
246 | may be used to see what a history expansion will do before using it. | |
247 | The @samp{-s} option to the @code{history} builtin may be used to | |
248 | add commands to the end of the history list without actually executing | |
249 | them, so that they are available for subsequent recall. | |
250 | This is most useful in conjunction with Readline. | |
251 | ||
252 | The shell allows control of the various characters used by the | |
253 | history expansion mechanism with the @code{histchars} variable. | |
254 | @end ifset | |
255 | ||
256 | @menu | |
257 | * Event Designators:: How to specify which history line to use. | |
258 | * Word Designators:: Specifying which words are of interest. | |
259 | * Modifiers:: Modifying the results of substitution. | |
260 | @end menu | |
261 | ||
262 | @node Event Designators | |
263 | @subsection Event Designators | |
264 | @cindex event designators | |
265 | ||
266 | An event designator is a reference to a command line entry in the | |
267 | history list. | |
268 | @cindex history events | |
269 | ||
270 | @table @asis | |
271 | ||
272 | @item @code{!} | |
273 | Start a history substitution, except when followed by a space, tab, | |
274 | the end of the line, @samp{=} or @samp{(}. | |
275 | ||
276 | @item @code{!@var{n}} | |
277 | Refer to command line @var{n}. | |
278 | ||
279 | @item @code{!-@var{n}} | |
280 | Refer to the command @var{n} lines back. | |
281 | ||
282 | @item @code{!!} | |
283 | Refer to the previous command. This is a synonym for @samp{!-1}. | |
284 | ||
285 | @item @code{!@var{string}} | |
286 | Refer to the most recent command starting with @var{string}. | |
287 | ||
288 | @item @code{!?@var{string}[?]} | |
289 | Refer to the most recent command containing @var{string}. The trailing | |
290 | @samp{?} may be omitted if the @var{string} is followed immediately by | |
291 | a newline. | |
292 | ||
293 | @item @code{^@var{string1}^@var{string2}^} | |
294 | Quick Substitution. Repeat the last command, replacing @var{string1} | |
295 | with @var{string2}. Equivalent to | |
296 | @code{!!:s/@var{string1}/@var{string2}/}. | |
297 | ||
298 | @item @code{!#} | |
299 | The entire command line typed so far. | |
300 | ||
301 | @end table | |
302 | ||
303 | @node Word Designators | |
304 | @subsection Word Designators | |
305 | ||
306 | Word designators are used to select desired words from the event. | |
307 | A @samp{:} separates the event specification from the word designator. It | |
308 | may be omitted if the word designator begins with a @samp{^}, @samp{$}, | |
309 | @samp{*}, @samp{-}, or @samp{%}. Words are numbered from the beginning | |
310 | of the line, with the first word being denoted by 0 (zero). Words are | |
311 | inserted into the current line separated by single spaces. | |
312 | ||
313 | @table @code | |
314 | ||
315 | @item 0 (zero) | |
316 | The @code{0}th word. For many applications, this is the command word. | |
317 | ||
318 | @item @var{n} | |
319 | The @var{n}th word. | |
320 | ||
321 | @item ^ | |
322 | The first argument; that is, word 1. | |
323 | ||
324 | @item $ | |
325 | The last argument. | |
326 | ||
327 | @item % | |
328 | The word matched by the most recent @samp{?@var{string}?} search. | |
329 | ||
330 | @item @var{x}-@var{y} | |
331 | A range of words; @samp{-@var{y}} abbreviates @samp{0-@var{y}}. | |
332 | ||
333 | @item * | |
334 | All of the words, except the @code{0}th. This is a synonym for @samp{1-$}. | |
335 | It is not an error to use @samp{*} if there is just one word in the event; | |
336 | the empty string is returned in that case. | |
337 | ||
338 | @item @var{x}* | |
339 | Abbreviates @samp{@var{x}-$} | |
340 | ||
341 | @item @var{x}- | |
342 | Abbreviates @samp{@var{x}-$} like @samp{@var{x}*}, but omits the last word. | |
343 | ||
344 | @end table | |
345 | ||
346 | If a word designator is supplied without an event specification, the | |
347 | previous command is used as the event. | |
348 | ||
349 | @node Modifiers | |
350 | @subsection Modifiers | |
351 | ||
352 | After the optional word designator, you can add a sequence of one or more | |
353 | of the following modifiers, each preceded by a @samp{:}. | |
354 | ||
355 | @table @code | |
356 | ||
357 | @item h | |
358 | Remove a trailing pathname component, leaving only the head. | |
359 | ||
360 | @item t | |
361 | Remove all leading pathname components, leaving the tail. | |
362 | ||
363 | @item r | |
364 | Remove a trailing suffix of the form @samp{.@var{suffix}}, leaving | |
365 | the basename. | |
366 | ||
367 | @item e | |
368 | Remove all but the trailing suffix. | |
369 | ||
370 | @item p | |
371 | Print the new command but do not execute it. | |
372 | ||
373 | @ifset BashFeatures | |
374 | @item q | |
375 | Quote the substituted words, escaping further substitutions. | |
376 | ||
377 | @item x | |
378 | Quote the substituted words as with @samp{q}, | |
379 | but break into words at spaces, tabs, and newlines. | |
380 | @end ifset | |
381 | ||
382 | @item s/@var{old}/@var{new}/ | |
383 | Substitute @var{new} for the first occurrence of @var{old} in the | |
384 | event line. Any delimiter may be used in place of @samp{/}. | |
385 | The delimiter may be quoted in @var{old} and @var{new} | |
386 | with a single backslash. If @samp{&} appears in @var{new}, | |
387 | it is replaced by @var{old}. A single backslash will quote | |
388 | the @samp{&}. The final delimiter is optional if it is the last | |
389 | character on the input line. | |
390 | ||
391 | @item & | |
392 | Repeat the previous substitution. | |
393 | ||
394 | @item g | |
395 | Cause changes to be applied over the entire event line. Used in | |
396 | conjunction with @samp{s}, as in @code{gs/@var{old}/@var{new}/}, | |
397 | or with @samp{&}. | |
398 | ||
399 | @end table |