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572a0c97 1\input texinfo @c -*-texinfo-*-
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2@c %**start of header
3@setfilename ../info/eshell
4@settitle Eshell: The Emacs Shell
18f952d5 5@synindex vr fn
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6@c %**end of header
7
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8@copying
9This manual is for Eshell, the Emacs shell.
b409f09b 10
b65d8176 11Copyright @copyright{} 1999, 2000, 2001, 2002, 2003, 2004,
4e6835db 122005, 2006, 2007 Free Software Foundation, Inc.
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13
14@quotation
b409f09b 15Permission is granted to copy, distribute and/or modify this document
678e7c71 16under the terms of the GNU Free Documentation License, Version 1.2 or
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17any later version published by the Free Software Foundation; with no
18Invariant Sections, with the Front-Cover texts being ``A GNU
19Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
20license is included in the section entitled ``GNU Free Documentation
21License'' in the Emacs manual.
22
23(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
24this GNU Manual, like GNU software. Copies published by the Free
25Software Foundation raise funds for GNU development.''
26
27This document is part of a collection distributed under the GNU Free
28Documentation License. If you want to distribute this document
29separately from the collection, you can do so by adding a copy of the
30license to the document, as described in section 6 of the license.
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31@end quotation
32@end copying
33
34@dircategory Emacs
35@direntry
36* Eshell: (eshell). A command shell implemented in Emacs Lisp.
37@end direntry
38
39@setchapternewpage on
572a0c97 40
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41@titlepage
42@sp 4
43@c The title is printed in a large font.
44@center @titlefont{User's Guide}
45@sp
46@center @titlefont{to}
47@sp
48@center @titlefont{Eshell: The Emacs Shell}
49@ignore
50@sp 2
dace60cf 51@center release 2.4
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52@c -release-
53@end ignore
54@sp 3
55@center John Wiegley
56@c -date-
57
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58@page
59@vskip 0pt plus 1filll
18f952d5 60@insertcopying
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61@end titlepage
62
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63@contents
64
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65@c ================================================================
66@c The real text starts here
67@c ================================================================
68
18f952d5 69@ifnottex
7d97fbf4 70@node Top, What is Eshell?, (dir), (dir)
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71@top Eshell
72
73This manual documents Eshell, a shell-like command interpretor
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74implemented in Emacs Lisp. It invokes no external processes except for
75those requested by the user. It is intended to be a functional
572a0c97 76replacement for command shells such as @command{bash}, @command{zsh},
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77@command{rc}, or @command{4dos}; since Emacs itself is capable of
78handling the sort of tasks accomplished by those tools.
79@c This manual is updated to release 2.4 of Eshell.
18f952d5 80@end ifnottex
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81
82@menu
219227ea 83* What is Eshell?:: A brief introduction to the Emacs Shell.
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84* Command basics:: The basics of command usage.
85* Commands::
86* Arguments::
87* Input/Output::
88* Process control::
89* Extension modules::
90* Extras and Goodies::
219227ea 91* Bugs and ideas:: Known problems, and future ideas.
84247bb5 92* GNU Free Documentation License:: The license for this documentation.
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93* Concept Index::
94* Function and Variable Index::
95* Key Index::
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96@end menu
97
7d97fbf4 98@node What is Eshell?
572a0c97 99@chapter What is Eshell?
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100@cindex what is Eshell?
101@cindex Eshell, what it is
572a0c97 102
dace60cf 103Eshell is a @dfn{command shell} written in Emacs Lisp. Everything it
219227ea 104does, it uses Emacs' facilities to do. This means that Eshell is as
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105portable as Emacs itself. It also means that cooperation with Lisp code
106is natural and seamless.
572a0c97 107
dace60cf 108What is a command shell? To properly understand the role of a shell,
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109it's necessary to visualize what a computer does for you. Basically, a
110computer is a tool; in order to use that tool, you must tell it what to
304724c2 111do---or give it ``commands.'' These commands take many forms, such as
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112clicking with a mouse on certain parts of the screen. But that is only
113one form of command input.
114
115By far the most versatile way to express what you want the computer to
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116do is by using an abbreviated language called @dfn{script}. In
117script, instead of telling the computer, ``list my files, please'',
118one writes a standard abbreviated command word---@samp{ls}. Typing
119@samp{ls} in a command shell is a script way of telling the computer
120to list your files.@footnote{This is comparable to viewing the
121contents of a folder using a graphical display.}
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122
123The real flexibility of this approach is apparent only when you realize
124that there are many, many different ways to list files. Perhaps you
125want them sorted by name, sorted by date, in reverse order, or grouped
126by type. Most graphical browsers have simple ways to express this. But
127what about showing only a few files, or only files that meet a certain
128criteria? In very complex and specific situations, the request becomes
129too difficult to express using a mouse or pointing device. It is just
130these kinds of requests that are easily solved using a command shell.
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131
132For example, what if you want to list every Word file on your hard
133drive, larger than 100 kilobytes in size, and which hasn't been looked
134at in over six months? That is a good candidate list for deletion, when
135you go to clean up your hard drive. But have you ever tried asking your
136computer for such a list? There is no way to do it! At least, not
137without using a command shell.
138
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139The role of a command shell is to give you more control over what your
140computer does for you. Not everyone needs this amount of control, and
141it does come at a cost: Learning the necessary script commands to
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142express what you want done. A complicated query, such as the example
143above, takes time to learn. But if you find yourself using your
144computer frequently enough, it is more than worthwhile in the long run.
dace60cf 145Any tool you use often deserves the time spent learning to master it.
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146@footnote{For the understandably curious, here is what that command
147looks like: But don't let it fool you; once you know what's going on,
148it's easier than it looks: @code{ls -lt **/*.doc(Lk+50aM+5)}.}
149
572a0c97 150@menu
dace60cf 151* Contributors to Eshell:: People who have helped out!
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152@end menu
153
7d97fbf4 154@node Contributors to Eshell
572a0c97 155@section Contributors to Eshell
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156@cindex contributors
157@cindex authors
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158
159Contributions to Eshell are welcome. I have limited time to work on
160this project, but I will gladly add any code you contribute to me to
161this package.
162
163The following persons have made contributions to Eshell.
164
165@itemize @bullet
166@item
167Eli Zaretskii made it possible for Eshell to run without requiring
168asynchronous subprocess support. This is important for MS-DOS, which
169does not have such support.@refill
170
171@item
172Miles Bader contributed many fixes during the port to Emacs 21.@refill
173
174@item
175Stefan Monnier fixed the things which bothered him, which of course made
176things better for all.@refill
177
178@item
179Gerd Moellmann also helped to contribute bug fixes during the initial
180integration with Emacs 21.@refill
181
182@item
183Alex Schroeder contributed code for interactively querying the user
184before overwriting files.@refill
185
186@item
187Sudish Joseph helped with some XEmacs compatibility issues.@refill
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188@end itemize
189
190Apart from these, a lot of people have sent suggestions, ideas,
191requests, bug reports and encouragement. Thanks a lot! Without you
192there would be no new releases of Eshell.
193
7d97fbf4 194@node Command basics
219227ea 195@chapter Basic overview
572a0c97 196
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197A command shell is a means of entering verbally-formed commands. This
198is really all that it does, and every feature described in this manual
199is a means to that end. Therefore, it's important to take firm hold on
200exactly what a command is, and how it fits in the overall picture of
201things.
572a0c97 202
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203@menu
204* Commands verbs:: Commands always begin with a verb.
205* Command arguments:: Some verbs require arguments.
206@end menu
207
7d97fbf4 208@node Commands verbs
dace60cf 209@section Commands verbs
572a0c97 210
dace60cf 211Commands are expressed using @dfn{script}, a special shorthand language
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212computers can understand with no trouble. Script is an extremely simple
213language; oddly enough, this is what makes it look so complicated!
214Whereas normal languages use a variety of embellishments, the form of a
215script command is always:
572a0c97 216
dace60cf 217@example
304724c2 218@var{verb} [@var{arguments}]
dace60cf 219@end example
572a0c97 220
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221The verb expresses what you want your computer to do. There are a fixed
222number of verbs, although this number is usually quite large. On the
223author's computer, it reaches almost 1400 in number. But of course,
224only a handful of these are really necessary.
572a0c97 225
dace60cf 226Sometimes, the verb is all that's written. A verb is always a single
219227ea 227word, usually related to the task it performs. @command{reboot} is a
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228good example. Entering that on GNU/Linux will reboot the
229computer---assuming you have sufficient privileges.
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230
231Other verbs require more information. These are usually very capable
232verbs, and must be told specifically what to do. The extra information
233is given in the form of @dfn{arguments}. For example, the
234@command{echo} verb prints back whatever arguments you type. It
235requires these arguments to know what to echo. A proper use of
dace60cf 236@command{echo} looks like this:
572a0c97 237
dace60cf 238@example
304724c2 239echo This is an example of using echo!
dace60cf 240@end example
572a0c97 241
219227ea 242This script command causes the computer to echo back: ``This is an
304724c2 243example of using echo!''
572a0c97 244
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245Although command verbs are always simple words, like @command{reboot} or
246@command{echo}, arguments may have a wide variety of forms. There are
247textual arguments, numerical arguments---even Lisp arguments.
248Distinguishing these different types of arguments requires special
249typing, for the computer to know exactly what you mean.
572a0c97 250
7d97fbf4 251@node Command arguments
dace60cf 252@section Command arguments
572a0c97 253
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254Eshell recognizes several different kinds of command arguments:
255
256@enumerate
257@item Strings (also called textual arguments)
258@item Numbers (floating point or integer)
259@item Lisp lists
260@item Lisp symbols
261@item Emacs buffers
262@item Emacs process handles
263@end enumerate
264
1fc0f361 265Most users need to worry only about the first two. The third, Lisp lists,
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266occur very frequently, but almost always behind the scenes.
267
268Strings are the most common type of argument, and consist of nearly any
269character. Special characters---those used by Eshell
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270specifically---must be preceded by a backslash (@samp{\}). When in doubt, it
271is safe to add backslashes anywhere and everywhere.
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272
273Here is a more complicated @command{echo} example:
274
275@example
304724c2 276echo A\ Multi-word\ Argument\ With\ A\ \$\ dollar
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277@end example
278
279Beyond this, things get a bit more complicated. While not beyond the
280reach of someone wishing to learn, it is definitely beyond the scope of
281this manual to present it all in a simplistic manner. Get comfortable
282with Eshell as a basic command invocation tool, and learn more about the
283commands on your system; then come back when it all sits more familiarly
284on your mind. Have fun!
285
7d97fbf4 286@node Commands
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287@chapter Commands
288
289@menu
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290* Invocation::
291* Completion::
292* Aliases::
293* History::
294* Scripts::
7d97fbf4 295* Built-ins::
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296@end menu
297
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298Essentially, a command shell is all about invoking commands---and
299everything that entails. So understanding how Eshell invokes commands
300is the key to comprehending how it all works.
301
7d97fbf4 302@node Invocation
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303@section Invocation
304
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305Unlike regular system shells, Eshell never invokes kernel functions
306directly, such as @code{exec(3)}. Instead, it uses the Lisp functions
307available in the Emacs Lisp library. It does this by transforming the
308command you specify into a callable Lisp form.@footnote{To see the Lisp
309form that will be invoked, type: @samp{eshell-parse-command "echo
310hello"}}
311
312This transformation, from the string of text typed at the command
313prompt, to the ultimate invocation of either a Lisp function or external
314command, follows these steps:
315
316@enumerate
317@item Parse the command string into separate arguments.
177c0ea7 318@item
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319@end enumerate
320
7d97fbf4 321@node Completion
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322@section Completion
323
7d97fbf4 324@node Aliases
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325@section Aliases
326
7d97fbf4 327@node History
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328@section History
329
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330Eshell knows a few built-in variables:
331
332@table @code
333
334@item $+
335@vindex $+
336This variable always contains the current working directory.
337
338@item $-
339@vindex $-
340This variable always contains the previous working directory (the
341current working directory from before the last @code{cd} command).
342
343@end table
344
345@node Scripts
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346@section Scripts
347
348
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349@node Built-ins
350@section Built-in commands
351
352Here is a list of built-in commands that Eshell knows about:
353
354@table @code
355
356@item cd
357@findex cd
358This command changes the current working directory. Usually, it is
359invoked as @samp{cd foo} where @file{foo} is the new working
360directory. But @code{cd} knows about a few special arguments:
361
362When it receives no argument at all, it changes to the home directory.
363
364Giving the command @samp{cd -} changes back to the previous working
365directory (this is the same as @samp{cd $-}).
366
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367The command @samp{cd =} shows the directory stack. Each line is
368numbered.
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369
370With @samp{cd =foo}, Eshell searches the directory stack for a
371directory matching the regular expression @samp{foo} and changes to
372that directory.
373
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374With @samp{cd -42}, you can access the directory stack by number.
375
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376@end table
377
378
379@node Arguments
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380@chapter Arguments
381
382@menu
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383* The Parser::
384* Variables::
385* Substitution::
386* Globbing::
387* Predicates::
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388@end menu
389
7d97fbf4 390@node The Parser
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391@section The Parser
392
7d97fbf4 393@node Variables
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394@section Variables
395
7d97fbf4 396@node Substitution
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397@section Substitution
398
7d97fbf4 399@node Globbing
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400@section Globbing
401
7d97fbf4 402@node Predicates
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403@section Predicates
404
405
7d97fbf4 406@node Input/Output
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407@chapter Input/Output
408
7d97fbf4 409@node Process control
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410@chapter Process control
411
412
7d97fbf4 413@node Extension modules
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414@chapter Extension modules
415
416@menu
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417* Writing a module::
418* Module testing::
419* Directory handling::
420* Key rebinding::
421* Smart scrolling::
422* Terminal emulation::
423* Built-in UNIX commands::
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424@end menu
425
7d97fbf4 426@node Writing a module
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427@section Writing a module
428
7d97fbf4 429@node Module testing
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430@section Module testing
431
7d97fbf4 432@node Directory handling
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433@section Directory handling
434
7d97fbf4 435@node Key rebinding
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436@section Key rebinding
437
7d97fbf4 438@node Smart scrolling
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439@section Smart scrolling
440
7d97fbf4 441@node Terminal emulation
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442@section Terminal emulation
443
7d97fbf4 444@node Built-in UNIX commands
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445@section Built-in UNIX commands
446
447
7d97fbf4 448@node Extras and Goodies
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449@chapter Extras and Goodies
450
7d97fbf4 451@node Bugs and ideas
572a0c97 452@chapter Bugs and ideas
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453@cindex reporting bugs and ideas
454@cindex bugs, how to report them
455@cindex author, how to reach
456@cindex email to the author
572a0c97 457@cindex FAQ
997c7f71 458@cindex problems, list of common
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459
460If you find a bug or misfeature, don't hesitate to let me know! Send
997c7f71 461email to @email{johnw@@gnu.org}. Feature requests should also be sent
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462there. I prefer discussing one thing at a time. If you find several
463unrelated bugs, please report them separately.
464
465If you have ideas for improvements, or if you have written some
466extensions to this package, I would like to hear from you. I hope you
467find this package useful!
468
469@menu
177c0ea7 470* Known problems::
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471@end menu
472
7d97fbf4 473@node Known problems
572a0c97 474@section Known problems
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475@cindex known bugs
476@cindex bugs, known
572a0c97 477
04171c28 478Below is complete list of known problems with Eshell version 2.4.2,
e088c9fd 479which is the version included with Emacs 22.
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480
481@table @asis
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482@item Documentation incomplete
483
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484@item Differentiate between aliases and functions
485
486Allow for a bash-compatible syntax, such as:
487
488@example
489alias arg=blah
dbdc47a3 490function arg () @{ blah $* @}
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491@end example
492
493@item @samp{for i in 1 2 3 @{ grep -q a b && *echo has it @} | wc -l} outputs result after prompt
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494
495In fact, piping to a process from a looping construct doesn't work in
496general. If I change the call to @code{eshell-copy-handles} in
497@code{eshell-rewrite-for-command} to use @code{eshell-protect}, it seems
498to work, but the output occurs after the prompt is displayed. The whole
499structured command thing is too complicated at present.
500
501@item Error with @command{bc} in @code{eshell-test}
502
503On some XEmacs system, the subprocess interaction test fails
997c7f71 504inexplicably, although @command{bc} works fine at the command prompt.
572a0c97 505
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506@item Eshell does not delete @file{*Help*} buffers in XEmacs 21.1.8+
507
508In XEmacs 21.1.8, the @file{*Help*} buffer has been renamed such that
509multiple instances of the @file{*Help*} buffer can exist.
510
511@item Pcomplete sometimes gets stuck
512
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513You press @key{TAB}, but no completions appear, even though the
514directory has matching files. This behavior is rare.
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515
516@item @samp{grep python $<rpm -qa>} doesn't work, but using @samp{*grep} does
517
518This happens because the @code{grep} Lisp function returns immediately,
519and then the asynchronous @command{grep} process expects to examine the
520temporary file, which has since been deleted.
521
522@item Problem with C-r repeating text
523
524If the text @emph{before point} reads "./run", and you type @kbd{C-r r u
525n}, it will repeat the line for every character typed.
526
527@item Backspace doesn't scroll back after continuing (in smart mode)
528
529Hitting space during a process invocation, such as @command{make}, will
530cause it to track the bottom of the output; but backspace no longer
531scrolls back.
532
533@item It's not possible to fully @code{unload-feature} Eshell
534
535@item Menu support was removed, but never put back
536
537@item Using C-p and C-n with rebind gets into a locked state
538
28665d46 539This happened a few times in Emacs 21, but has been unreproducible
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540since.
541
542@item If an interactive process is currently running, @kbd{M-!} doesn't work
543
544@item Use a timer instead of @code{sleep-for} when killing child processes
545
546@item Piping to a Lisp function is not supported
547
548Make it so that the Lisp command on the right of the pipe is repeatedly
549called with the input strings as arguments. This will require changing
dace60cf 550@code{eshell-do-pipeline} to handle non-process targets.
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551
552@item Input redirection is not supported
553
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554See the above entry.
555
219227ea 556@item Problem running @command{less} without arguments on Windows
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557
558The result in the Eshell buffer is:
559
560@example
561Spawning child process: invalid argument
562@end example
563
564Also a new @command{less} buffer was created with nothing in it@dots{}
565(presumably this holds the output of @command{less}).
566
567If @command{less.exe} is invoked from the Eshell command line, the
568expected output is written to the buffer.
569
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570Note that this happens on NT-Emacs 20.6.1 on Windows 2000. The term.el
571package and the supplied shell both use the @command{cmdproxy} program
572for running shells.
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573
574@item Implement @samp{-r}, @samp{-n} and @samp{-s} switches for @command{cp}
575
576@item Make @kbd{M-5 M-x eshell} switch to ``*eshell<5>*'', creating if need be
577
bbd9b8db 578@item @samp{mv @var{dir} @var{file}.tar} does not remove directories
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579
580This is because the tar option --remove-files doesn't do so. Should it
581be Eshell's job?
582
583@item Bind @code{standard-output} and @code{standard-error}
584
585This would be so that if a Lisp function calls @code{print}, everything
586will happen as it should (albeit slowly).
587
588@item When an extension module fails to load, @samp{cd /} gives a Lisp error
589
590@item If a globbing pattern returns one match, should it be a list?
591
592@item Make sure syntax table is correct in Eshell mode
593
594So that @kbd{M-DEL} acts in a predictable manner, etc.
595
596@item Allow all Eshell buffers to share the same history and list-dir
597
598@item There is a problem with script commands that output to @file{/dev/null}
599
600If a script file, somewhere in the middle, uses @samp{> /dev/null},
601output from all subsequent commands is swallowed.
602
603@item Split up parsing of text after @samp{$} in @file{esh-var.el}
604
605Make it similar to the way that @file{esh-arg.el} is structured.
606Then add parsing of @samp{$[?\n]}.
607
608@item After pressing @kbd{M-RET}, redisplay before running the next command
609
610@item Argument predicates and modifiers should work anywhere in a path
611
612@example
613/usr/local/src/editors/vim $ vi **/CVS(/)/Root(.)
614Invalid regexp: "Unmatched ( or \\("
615@end example
616
617With @command{zsh}, the glob above expands to all files named
618@file{Root} in directories named @file{CVS}.
619
dbdc47a3 620@item Typing @samp{echo $@{locate locate@}/bin<TAB>} results in a Lisp error
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621
622Perhaps it should interpolate all permutations, and make that the
623globbing result, since otherwise hitting return here will result in
624``(list of filenames)/bin'', which is never valuable. Thus, one could
dbdc47a3 625@command{cat} only C backup files by using @samp{ls $@{identity *.c@}~}.
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626In that case, having an alias command name @command{glob} for
627@command{identity} would be useful.
628
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629@item Once symbolic mode is supported for @command{umask}, implement @command{chmod} in Lisp
630
631@item Create @code{eshell-expand-file-name}
632
633This would use a data table to transform things such as @samp{~+},
634@samp{...}, etc.
635
636@item Abstract @file{em-smart.el} into @file{smart-scroll.el}
637
638It only really needs: to be hooked onto the output filter and the
639pre-command hook, and to have the input-end and input-start markers.
304724c2 640And to know whether the last output group was ``successful.''
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641
642@item Allow for fully persisting the state of Eshell
643
644This would include: variables, history, buffer, input, dir stack, etc.
645
646@item Implement D as an argument predicate
647
648It means that files beginning with a dot should be included in the
649glob match.
650
651@item A comma in a predicate list should mean OR
652
653At the moment, this is not supported.
654
655@item Error if a glob doesn't expand due to a predicate
656
657An error should be generated only if @code{eshell-error-if-no-glob} is
bf301e70 658non-@code{nil}.
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659
660@item @samp{(+ RET SPC TAB} does not cause @code{indent-according-to-mode} to occur
661
662@item Create @code{eshell-auto-accumulate-list}
663
664This is a list of commands for which, if the user presses @kbd{RET}, the
665text is staged as the next Eshell command, rather than being sent to the
666current interactive process.
667
668@item Display file and line number if an error occurs in a script
669
670@item @command{wait} doesn't work with process ids at the moment
671
672@item Enable the direct-to-process input code in @file{em-term.el}
673
674@item Problem with repeating @samp{echo $@{find /tmp@}}
675
676With smart display active, if @kbd{RET} is held down, after a while it
677can't keep up anymore and starts outputting blank lines. It only
678happens if an asynchronous process is involved@dots{}
679
680I think the problem is that @code{eshell-send-input} is resetting the
681input target location, so that if the asynchronous process is not done
682by the time the next @kbd{RET} is received, the input processor thinks
683that the input is meant for the process; which, when smart display is
684enabled, will be the text of the last command line! That is a bug in
685itself.
686
687In holding down @kbd{RET} while an asynchronous process is running,
688there will be a point in between termination of the process, and the
689running of @code{eshell-post-command-hook}, which would cause
690@code{eshell-send-input} to call @code{eshell-copy-old-input}, and then
691process that text as a command to be run after the process. Perhaps
692there should be a way of killing pending input between the death of the
693process, and the @code{post-command-hook}.
694
695@item Allow for a more aggressive smart display mode
696
697Perhaps toggled by a command, that makes each output block a smart
698display block.
699
700@item Create more meta variables
701
702@table @samp
703@item $!
704The reason for the failure of the last disk command, or the text of the
705last Lisp error.
706
707@item $=
708A special associate array, which can take references of the form
709@samp{$=[REGEXP]}. It indexes into the directory ring.
710@end table
711
712@item Eshell scripts can't execute in the background
713
bbd9b8db 714@item Support zsh's ``Parameter Expansion'' syntax, i.e. @samp{$@{@var{name}:-@var{val}@}}
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715
716@item Write an @command{info} alias that can take arguments
717
718So that the user can enter @samp{info chmod}, for example.
719
720@item Create a mode @code{eshell-browse}
721
722It would treat the Eshell buffer as a outline. Collapsing the outline
723hides all of the output text. Collapsing again would show only the
724first command run in each directory
725
726@item Allow other revisions of a file to be referenced using @samp{file@{rev@}}
727
728This would be expanded by @code{eshell-expand-file-name} (see above).
729
730@item Print ``You have new mail'' when the ``Mail'' icon is turned on
731
732@item Implement @kbd{M-|} for Eshell
733
734@item Implement input redirection
735
736If it's a Lisp function, input redirection implies @command{xargs} (in a
737way@dots{}). If input redirection is added, also update the
738@code{file-name-quote-list}, and the delimiter list.
739
bbd9b8db 740@item Allow @samp{#<@var{word} @var{arg}>} as a generic syntax
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741
742With the handling of @emph{word} specified by an
743@code{eshell-special-alist}.
744
219227ea 745@item In @code{eshell-veal-using-options}, allow a @code{:complete} tag
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746
747It would be used to provide completion rules for that command. Then the
748macro will automagically define the completion function.
749
750@item For @code{eshell-command-on-region}, apply redirections to the result
751
752So that @samp{+ > 'blah} would cause the result of the @code{+} (using
753input from the current region) to be inserting into the symbol
754@code{blah}.
755
756If an external command is being invoked, the input is sent as standard
757input, as if a @samp{cat <region> |} had been invoked.
758
759If a Lisp command, or an alias, is invoked, then if the line has no
760newline characters, it is divided by whitespace and passed as arguments
761to the Lisp function. Otherwise, it is divided at the newline
762characters. Thus, invoking @code{+} on a series of numbers will add
763them; @code{min} would display the smallest figure, etc.
764
765@item Write @code{eshell-script-mode} as a minor mode
766
767It would provide syntax, abbrev, highlighting and indenting support like
768@code{emacs-lisp-mode} and @code{shell-mode}.
769
770@item In the history mechanism, finish the @command{bash}-style support
771
772This means @samp{!n}, @samp{!#}, @samp{!:%}, and @samp{!:1-} as separate
773from @samp{!:1*}.
774
775@item Support the -n command line option for @command{history}
776
777@item Implement @command{fc} in Lisp
778
779@item Specifying a frame as a redirection target should imply the currently active window's buffer
780
bbd9b8db 781@item Implement @samp{>@var{func-or-func-list}}
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782
783This would allow for an ``output translators'', that take a function to
784modify output with, and a target. Devise a syntax that works well with
28665d46 785pipes, and can accommodate multiple functions (i.e., @samp{>'(upcase
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786regexp-quote)} or @samp{>'upcase}).
787
788@item Allow Eshell to read/write to/from standard input and output
789
790This would be optional, rather than always using the Eshell buffer.
791This would allow it to be run from the command line (perhaps).
792
793@item Write a @command{help} command
794
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795It would call subcommands with @option{--help}, or @option{-h} or
796@option{/?}, as appropriate.
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797
798@item Implement @command{stty} in Lisp
799
bbd9b8db 800@item Support @command{rc}'s matching operator, e.g. @samp{~ (@var{list}) @var{regexp}}
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801
802@item Implement @command{bg} and @command{fg} as editors of @code{eshell-process-list}
803
804Using @command{bg} on a process that is already in the background does
805nothing. Specifying redirection targets replaces (or adds) to the list
806current being used.
807
808@item Have @command{jobs} print only the processes for the current shell
809
810@item How can Eshell learn if a background process has requested input?
811
812@item Support @samp{2>&1} and @samp{>&} and @samp{2>} and @samp{|&}
813
814The syntax table for parsing these should be customizable, such that the
815user could change it to use rc syntax: @samp{>[2=1]}.
816
817@item Allow @samp{$_[-1]}, which would indicate the last element of the array
818
819@item Make @samp{$x[*]} equal to listing out the full contents of @samp{x}
820
821Return them as a list, so that @samp{$_[*]} is all the arguments of the
822last command.
823
824@item Copy ANSI code handling from @file{term.el} into @file{em-term.el}
825
826Make it possible for the user to send char-by-char to the underlying
827process. Ultimately, I should be able to move away from using term.el
828altogether, since everything but the ANSI code handling is already part
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829of Eshell. Then, things would work correctly on MS-Windows as well
830(which doesn't have @file{/bin/sh}, although @file{term.el} tries to use
831it).
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832
833@item Make the shell spawning commands be visual
834
835That is, make (@command{su}, @command{bash}, @command{telnet},
836@command{rlogin}, @command{rsh}, etc.) be part of
837@code{eshell-visual-commands}. The only exception is if the shell is
838being used to invoke a single command. Then, the behavior should be
839based on what that command is.
840
bbd9b8db 841@item Create a smart viewing command named @command{open}
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842
843This would search for some way to open its argument (similar to opening
844a file in the Windows Explorer).
845
846@item Alias @command{read} to be the same as @command{open}, only read-only
847
848@item Write a @command{tail} command which uses @code{view-file}
849
850It would move point to the end of the buffer, and then turns on
851auto-revert mode in that buffer at frequent intervals---and a
4dc5fe62 852@command{head} alias which assumes an upper limit of
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853@code{eshell-maximum-line-length} characters per line.
854
855@item Make @command{dgrep} load @code{dired}, mark everything, then invoke @code{dired-do-search}
856
219227ea 857@item Write mesh.c
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858
859This would run Emacs with the appropriate arguments to invoke Eshell
860only. That way, it could be listed as a login shell.
861
862@item Use an intangible @code{PS2} string for multi-line input prompts
863
864@item Auto-detect when a command is visual, by checking @code{TERMCAP} usage
865
866@item The first keypress after @kbd{M-x watson} triggers `eshell-send-input'
867
868@item Make @kbd{/} electric
869
870So that it automatically expands and corrects pathnames. Or make
871pathname completion for Pcomplete auto-expand @samp{/u/i/std<TAB>} to
872@samp{/usr/include/std<TAB>}.
873
874@item Write the @command{pushd} stack to disk along with @code{last-dir-ring}
875
876@item Add options to @code{eshell/cat} which would allow it to sort and uniq
877
878@item Implement @command{wc} in Lisp
879
880Add support for counting sentences, paragraphs, pages, etc.
881
882@item Once piping is added, implement @command{sort} and @command{uniq} in Lisp
883
884@item Implement @command{touch} in Lisp
885
886@item Implement @command{comm} in Lisp
887
888@item Implement an @command{epatch} command in Lisp
889
890This would call @code{ediff-patch-file}, or @code{ediff-patch-buffer},
891depending on its argument.
892
893@item Have an option such that @samp{ls -l} generates a dired buffer
894
895@item Write a version of @command{xargs} based on command rewriting
896
897That is, @samp{find X | xargs Y} would be indicated using @samp{Y
898$@{find X@}}. Maybe @code{eshell-do-pipelines} could be changed to
899perform this on-thy-fly rewriting.
900
901@item Write an alias for @command{less} that brings up a @code{view-mode} buffer
902
bbd9b8db 903Such that the user can press @key{SPC} and @key{DEL}, and then @key{q}
177c0ea7 904to return to Eshell. It would be equivalent to:
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905@samp{X > #<buffer Y>; view-buffer #<buffer Y>}.
906
907@item Make @code{eshell-mode} as much a full citizen as @code{shell-mode}
908
909Everywhere in Emacs where @code{shell-mode} is specially noticed, add
910@code{eshell-mode} there.
911
912@item Permit the umask to be selectively set on a @command{cp} target
913
914@item Problem using @kbd{M-x eshell} after using @code{eshell-command}
915
916If the first thing that I do after entering Emacs is to run
917@code{eshell-command} and invoke @command{ls}, and then use @kbd{M-x
918eshell}, it doesn't display anything.
919
920@item @kbd{M-RET} during a long command (using smart display) doesn't work
921
922Since it keeps the cursor up where the command was invoked.
923
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924@end table
925
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926@node GNU Free Documentation License
927@appendix GNU Free Documentation License
928@include doclicense.texi
929
7d97fbf4 930@node Concept Index
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931@unnumbered Concept Index
932
933@printindex cp
934
7d97fbf4 935@node Function and Variable Index
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936@unnumbered Function and Variable Index
937
938@printindex fn
939
7d97fbf4 940@node Key Index
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941@unnumbered Key Index
942
943@printindex ky
572a0c97 944@bye
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945
946@ignore
947 arch-tag: 776409ba-cb15-42b9-b2b6-d2bdc7ebad01
948@end ignore