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1 \input texinfo @c -*-texinfo-*-
2 @c %**start of header
3 @setfilename ../../info/eshell
4 @settitle Eshell: The Emacs Shell
5 @synindex vr fn
6 @c %**end of header
7
8 @copying
9 This manual is for Eshell, the Emacs shell.
10
11 Copyright @copyright{} 1999, 2000, 2001, 2002, 2003, 2004,
12 2005, 2006, 2007 Free Software Foundation, Inc.
13
14 @quotation
15 Permission is granted to copy, distribute and/or modify this document
16 under the terms of the GNU Free Documentation License, Version 1.2 or
17 any later version published by the Free Software Foundation; with no
18 Invariant Sections, with the Front-Cover texts being ``A GNU
19 Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
20 license is included in the section entitled ``GNU Free Documentation
21 License'' in the Emacs manual.
22
23 (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
24 this GNU Manual, like GNU software. Copies published by the Free
25 Software Foundation raise funds for GNU development.''
26
27 This document is part of a collection distributed under the GNU Free
28 Documentation License. If you want to distribute this document
29 separately from the collection, you can do so by adding a copy of the
30 license to the document, as described in section 6 of the license.
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
40
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
51 @center release 2.4
52 @c -release-
53 @end ignore
54 @sp 3
55 @center John Wiegley
56 @c -date-
57
58 @page
59 @vskip 0pt plus 1filll
60 @insertcopying
61 @end titlepage
62
63 @contents
64
65 @c ================================================================
66 @c The real text starts here
67 @c ================================================================
68
69 @ifnottex
70 @node Top, What is Eshell?, (dir), (dir)
71 @top Eshell
72
73 This manual documents Eshell, a shell-like command interpretor
74 implemented in Emacs Lisp. It invokes no external processes except for
75 those requested by the user. It is intended to be a functional
76 replacement for command shells such as @command{bash}, @command{zsh},
77 @command{rc}, or @command{4dos}; since Emacs itself is capable of
78 handling the sort of tasks accomplished by those tools.
79 @c This manual is updated to release 2.4 of Eshell.
80 @end ifnottex
81
82 @menu
83 * What is Eshell?:: A brief introduction to the Emacs Shell.
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::
91 * Bugs and ideas:: Known problems, and future ideas.
92 * GNU Free Documentation License:: The license for this documentation.
93 * Concept Index::
94 * Function and Variable Index::
95 * Key Index::
96 @end menu
97
98 @node What is Eshell?
99 @chapter What is Eshell?
100 @cindex what is Eshell?
101 @cindex Eshell, what it is
102
103 Eshell is a @dfn{command shell} written in Emacs Lisp. Everything it
104 does, it uses Emacs' facilities to do. This means that Eshell is as
105 portable as Emacs itself. It also means that cooperation with Lisp code
106 is natural and seamless.
107
108 What is a command shell? To properly understand the role of a shell,
109 it's necessary to visualize what a computer does for you. Basically, a
110 computer is a tool; in order to use that tool, you must tell it what to
111 do---or give it ``commands.'' These commands take many forms, such as
112 clicking with a mouse on certain parts of the screen. But that is only
113 one form of command input.
114
115 By far the most versatile way to express what you want the computer to
116 do is by using an abbreviated language called @dfn{script}. In
117 script, instead of telling the computer, ``list my files, please'',
118 one writes a standard abbreviated command word---@samp{ls}. Typing
119 @samp{ls} in a command shell is a script way of telling the computer
120 to list your files.@footnote{This is comparable to viewing the
121 contents of a folder using a graphical display.}
122
123 The real flexibility of this approach is apparent only when you realize
124 that there are many, many different ways to list files. Perhaps you
125 want them sorted by name, sorted by date, in reverse order, or grouped
126 by type. Most graphical browsers have simple ways to express this. But
127 what about showing only a few files, or only files that meet a certain
128 criteria? In very complex and specific situations, the request becomes
129 too difficult to express using a mouse or pointing device. It is just
130 these kinds of requests that are easily solved using a command shell.
131
132 For example, what if you want to list every Word file on your hard
133 drive, larger than 100 kilobytes in size, and which hasn't been looked
134 at in over six months? That is a good candidate list for deletion, when
135 you go to clean up your hard drive. But have you ever tried asking your
136 computer for such a list? There is no way to do it! At least, not
137 without using a command shell.
138
139 The role of a command shell is to give you more control over what your
140 computer does for you. Not everyone needs this amount of control, and
141 it does come at a cost: Learning the necessary script commands to
142 express what you want done. A complicated query, such as the example
143 above, takes time to learn. But if you find yourself using your
144 computer frequently enough, it is more than worthwhile in the long run.
145 Any tool you use often deserves the time spent learning to master it.
146 @footnote{For the understandably curious, here is what that command
147 looks like: But don't let it fool you; once you know what's going on,
148 it's easier than it looks: @code{ls -lt **/*.doc(Lk+50aM+5)}.}
149
150 @menu
151 * Contributors to Eshell:: People who have helped out!
152 @end menu
153
154 @node Contributors to Eshell
155 @section Contributors to Eshell
156 @cindex contributors
157 @cindex authors
158
159 Contributions to Eshell are welcome. I have limited time to work on
160 this project, but I will gladly add any code you contribute to me to
161 this package.
162
163 The following persons have made contributions to Eshell.
164
165 @itemize @bullet
166 @item
167 Eli Zaretskii made it possible for Eshell to run without requiring
168 asynchronous subprocess support. This is important for MS-DOS, which
169 does not have such support.@refill
170
171 @item
172 Miles Bader contributed many fixes during the port to Emacs 21.@refill
173
174 @item
175 Stefan Monnier fixed the things which bothered him, which of course made
176 things better for all.@refill
177
178 @item
179 Gerd Moellmann also helped to contribute bug fixes during the initial
180 integration with Emacs 21.@refill
181
182 @item
183 Alex Schroeder contributed code for interactively querying the user
184 before overwriting files.@refill
185
186 @item
187 Sudish Joseph helped with some XEmacs compatibility issues.@refill
188 @end itemize
189
190 Apart from these, a lot of people have sent suggestions, ideas,
191 requests, bug reports and encouragement. Thanks a lot! Without you
192 there would be no new releases of Eshell.
193
194 @node Command basics
195 @chapter Basic overview
196
197 A command shell is a means of entering verbally-formed commands. This
198 is really all that it does, and every feature described in this manual
199 is a means to that end. Therefore, it's important to take firm hold on
200 exactly what a command is, and how it fits in the overall picture of
201 things.
202
203 @menu
204 * Commands verbs:: Commands always begin with a verb.
205 * Command arguments:: Some verbs require arguments.
206 @end menu
207
208 @node Commands verbs
209 @section Commands verbs
210
211 Commands are expressed using @dfn{script}, a special shorthand language
212 computers can understand with no trouble. Script is an extremely simple
213 language; oddly enough, this is what makes it look so complicated!
214 Whereas normal languages use a variety of embellishments, the form of a
215 script command is always:
216
217 @example
218 @var{verb} [@var{arguments}]
219 @end example
220
221 The verb expresses what you want your computer to do. There are a fixed
222 number of verbs, although this number is usually quite large. On the
223 author's computer, it reaches almost 1400 in number. But of course,
224 only a handful of these are really necessary.
225
226 Sometimes, the verb is all that's written. A verb is always a single
227 word, usually related to the task it performs. @command{reboot} is a
228 good example. Entering that on GNU/Linux will reboot the
229 computer---assuming you have sufficient privileges.
230
231 Other verbs require more information. These are usually very capable
232 verbs, and must be told specifically what to do. The extra information
233 is given in the form of @dfn{arguments}. For example, the
234 @command{echo} verb prints back whatever arguments you type. It
235 requires these arguments to know what to echo. A proper use of
236 @command{echo} looks like this:
237
238 @example
239 echo This is an example of using echo!
240 @end example
241
242 This script command causes the computer to echo back: ``This is an
243 example of using echo!''
244
245 Although command verbs are always simple words, like @command{reboot} or
246 @command{echo}, arguments may have a wide variety of forms. There are
247 textual arguments, numerical arguments---even Lisp arguments.
248 Distinguishing these different types of arguments requires special
249 typing, for the computer to know exactly what you mean.
250
251 @node Command arguments
252 @section Command arguments
253
254 Eshell 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
265 Most users need to worry only about the first two. The third, Lisp lists,
266 occur very frequently, but almost always behind the scenes.
267
268 Strings are the most common type of argument, and consist of nearly any
269 character. Special characters---those used by Eshell
270 specifically---must be preceded by a backslash (@samp{\}). When in doubt, it
271 is safe to add backslashes anywhere and everywhere.
272
273 Here is a more complicated @command{echo} example:
274
275 @example
276 echo A\ Multi-word\ Argument\ With\ A\ \$\ dollar
277 @end example
278
279 Beyond this, things get a bit more complicated. While not beyond the
280 reach of someone wishing to learn, it is definitely beyond the scope of
281 this manual to present it all in a simplistic manner. Get comfortable
282 with Eshell as a basic command invocation tool, and learn more about the
283 commands on your system; then come back when it all sits more familiarly
284 on your mind. Have fun!
285
286 @node Commands
287 @chapter Commands
288
289 @menu
290 * Invocation::
291 * Completion::
292 * Aliases::
293 * History::
294 * Scripts::
295 * Built-ins::
296 @end menu
297
298 Essentially, a command shell is all about invoking commands---and
299 everything that entails. So understanding how Eshell invokes commands
300 is the key to comprehending how it all works.
301
302 @node Invocation
303 @section Invocation
304
305 Unlike regular system shells, Eshell never invokes kernel functions
306 directly, such as @code{exec(3)}. Instead, it uses the Lisp functions
307 available in the Emacs Lisp library. It does this by transforming the
308 command you specify into a callable Lisp form.@footnote{To see the Lisp
309 form that will be invoked, type: @samp{eshell-parse-command "echo
310 hello"}}
311
312 This transformation, from the string of text typed at the command
313 prompt, to the ultimate invocation of either a Lisp function or external
314 command, follows these steps:
315
316 @enumerate
317 @item Parse the command string into separate arguments.
318 @item
319 @end enumerate
320
321 @node Completion
322 @section Completion
323
324 @node Aliases
325 @section Aliases
326
327 @node History
328 @section History
329
330 Eshell knows a few built-in variables:
331
332 @table @code
333
334 @item $+
335 @vindex $+
336 This variable always contains the current working directory.
337
338 @item $-
339 @vindex $-
340 This variable always contains the previous working directory (the
341 current working directory from before the last @code{cd} command).
342
343 @end table
344
345 @node Scripts
346 @section Scripts
347
348
349 @node Built-ins
350 @section Built-in commands
351
352 Here is a list of built-in commands that Eshell knows about:
353
354 @table @code
355
356 @item cd
357 @findex cd
358 This command changes the current working directory. Usually, it is
359 invoked as @samp{cd foo} where @file{foo} is the new working
360 directory. But @code{cd} knows about a few special arguments:
361
362 When it receives no argument at all, it changes to the home directory.
363
364 Giving the command @samp{cd -} changes back to the previous working
365 directory (this is the same as @samp{cd $-}).
366
367 The command @samp{cd =} shows the directory stack. Each line is
368 numbered.
369
370 With @samp{cd =foo}, Eshell searches the directory stack for a
371 directory matching the regular expression @samp{foo} and changes to
372 that directory.
373
374 With @samp{cd -42}, you can access the directory stack by number.
375
376 @end table
377
378
379 @node Arguments
380 @chapter Arguments
381
382 @menu
383 * The Parser::
384 * Variables::
385 * Substitution::
386 * Globbing::
387 * Predicates::
388 @end menu
389
390 @node The Parser
391 @section The Parser
392
393 @node Variables
394 @section Variables
395
396 @node Substitution
397 @section Substitution
398
399 @node Globbing
400 @section Globbing
401
402 @node Predicates
403 @section Predicates
404
405
406 @node Input/Output
407 @chapter Input/Output
408
409 @node Process control
410 @chapter Process control
411
412
413 @node Extension modules
414 @chapter Extension modules
415
416 @menu
417 * Writing a module::
418 * Module testing::
419 * Directory handling::
420 * Key rebinding::
421 * Smart scrolling::
422 * Terminal emulation::
423 * Built-in UNIX commands::
424 @end menu
425
426 @node Writing a module
427 @section Writing a module
428
429 @node Module testing
430 @section Module testing
431
432 @node Directory handling
433 @section Directory handling
434
435 @node Key rebinding
436 @section Key rebinding
437
438 @node Smart scrolling
439 @section Smart scrolling
440
441 @node Terminal emulation
442 @section Terminal emulation
443
444 @node Built-in UNIX commands
445 @section Built-in UNIX commands
446
447
448 @node Extras and Goodies
449 @chapter Extras and Goodies
450
451 @node Bugs and ideas
452 @chapter Bugs and ideas
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
457 @cindex FAQ
458 @cindex problems, list of common
459
460 If you find a bug or misfeature, don't hesitate to let me know! Send
461 email to @email{johnw@@gnu.org}. Feature requests should also be sent
462 there. I prefer discussing one thing at a time. If you find several
463 unrelated bugs, please report them separately.
464
465 If you have ideas for improvements, or if you have written some
466 extensions to this package, I would like to hear from you. I hope you
467 find this package useful!
468
469 @menu
470 * Known problems::
471 @end menu
472
473 @node Known problems
474 @section Known problems
475 @cindex known bugs
476 @cindex bugs, known
477
478 Below is complete list of known problems with Eshell version 2.4.2,
479 which is the version included with Emacs 22.
480
481 @table @asis
482 @item Documentation incomplete
483
484 @item Differentiate between aliases and functions
485
486 Allow for a bash-compatible syntax, such as:
487
488 @example
489 alias arg=blah
490 function arg () @{ blah $* @}
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
494
495 In fact, piping to a process from a looping construct doesn't work in
496 general. If I change the call to @code{eshell-copy-handles} in
497 @code{eshell-rewrite-for-command} to use @code{eshell-protect}, it seems
498 to work, but the output occurs after the prompt is displayed. The whole
499 structured command thing is too complicated at present.
500
501 @item Error with @command{bc} in @code{eshell-test}
502
503 On some XEmacs system, the subprocess interaction test fails
504 inexplicably, although @command{bc} works fine at the command prompt.
505
506 @item Eshell does not delete @file{*Help*} buffers in XEmacs 21.1.8+
507
508 In XEmacs 21.1.8, the @file{*Help*} buffer has been renamed such that
509 multiple instances of the @file{*Help*} buffer can exist.
510
511 @item Pcomplete sometimes gets stuck
512
513 You press @key{TAB}, but no completions appear, even though the
514 directory has matching files. This behavior is rare.
515
516 @item @samp{grep python $<rpm -qa>} doesn't work, but using @samp{*grep} does
517
518 This happens because the @code{grep} Lisp function returns immediately,
519 and then the asynchronous @command{grep} process expects to examine the
520 temporary file, which has since been deleted.
521
522 @item Problem with C-r repeating text
523
524 If the text @emph{before point} reads "./run", and you type @kbd{C-r r u
525 n}, it will repeat the line for every character typed.
526
527 @item Backspace doesn't scroll back after continuing (in smart mode)
528
529 Hitting space during a process invocation, such as @command{make}, will
530 cause it to track the bottom of the output; but backspace no longer
531 scrolls 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
539 This happened a few times in Emacs 21, but has been unreproducible
540 since.
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
548 Make it so that the Lisp command on the right of the pipe is repeatedly
549 called with the input strings as arguments. This will require changing
550 @code{eshell-do-pipeline} to handle non-process targets.
551
552 @item Input redirection is not supported
553
554 See the above entry.
555
556 @item Problem running @command{less} without arguments on Windows
557
558 The result in the Eshell buffer is:
559
560 @example
561 Spawning child process: invalid argument
562 @end example
563
564 Also a new @command{less} buffer was created with nothing in it@dots{}
565 (presumably this holds the output of @command{less}).
566
567 If @command{less.exe} is invoked from the Eshell command line, the
568 expected output is written to the buffer.
569
570 Note that this happens on NT-Emacs 20.6.1 on Windows 2000. The term.el
571 package and the supplied shell both use the @command{cmdproxy} program
572 for running shells.
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
578 @item @samp{mv @var{dir} @var{file}.tar} does not remove directories
579
580 This is because the tar option --remove-files doesn't do so. Should it
581 be Eshell's job?
582
583 @item Bind @code{standard-output} and @code{standard-error}
584
585 This would be so that if a Lisp function calls @code{print}, everything
586 will 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
594 So 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
600 If a script file, somewhere in the middle, uses @samp{> /dev/null},
601 output from all subsequent commands is swallowed.
602
603 @item Split up parsing of text after @samp{$} in @file{esh-var.el}
604
605 Make it similar to the way that @file{esh-arg.el} is structured.
606 Then 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(.)
614 Invalid regexp: "Unmatched ( or \\("
615 @end example
616
617 With @command{zsh}, the glob above expands to all files named
618 @file{Root} in directories named @file{CVS}.
619
620 @item Typing @samp{echo $@{locate locate@}/bin<TAB>} results in a Lisp error
621
622 Perhaps it should interpolate all permutations, and make that the
623 globbing result, since otherwise hitting return here will result in
624 ``(list of filenames)/bin'', which is never valuable. Thus, one could
625 @command{cat} only C backup files by using @samp{ls $@{identity *.c@}~}.
626 In that case, having an alias command name @command{glob} for
627 @command{identity} would be useful.
628
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
633 This 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
638 It only really needs: to be hooked onto the output filter and the
639 pre-command hook, and to have the input-end and input-start markers.
640 And to know whether the last output group was ``successful.''
641
642 @item Allow for fully persisting the state of Eshell
643
644 This would include: variables, history, buffer, input, dir stack, etc.
645
646 @item Implement D as an argument predicate
647
648 It means that files beginning with a dot should be included in the
649 glob match.
650
651 @item A comma in a predicate list should mean OR
652
653 At the moment, this is not supported.
654
655 @item Error if a glob doesn't expand due to a predicate
656
657 An error should be generated only if @code{eshell-error-if-no-glob} is
658 non-@code{nil}.
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
664 This is a list of commands for which, if the user presses @kbd{RET}, the
665 text is staged as the next Eshell command, rather than being sent to the
666 current 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
676 With smart display active, if @kbd{RET} is held down, after a while it
677 can't keep up anymore and starts outputting blank lines. It only
678 happens if an asynchronous process is involved@dots{}
679
680 I think the problem is that @code{eshell-send-input} is resetting the
681 input target location, so that if the asynchronous process is not done
682 by the time the next @kbd{RET} is received, the input processor thinks
683 that the input is meant for the process; which, when smart display is
684 enabled, will be the text of the last command line! That is a bug in
685 itself.
686
687 In holding down @kbd{RET} while an asynchronous process is running,
688 there will be a point in between termination of the process, and the
689 running of @code{eshell-post-command-hook}, which would cause
690 @code{eshell-send-input} to call @code{eshell-copy-old-input}, and then
691 process that text as a command to be run after the process. Perhaps
692 there should be a way of killing pending input between the death of the
693 process, and the @code{post-command-hook}.
694
695 @item Allow for a more aggressive smart display mode
696
697 Perhaps toggled by a command, that makes each output block a smart
698 display block.
699
700 @item Create more meta variables
701
702 @table @samp
703 @item $!
704 The reason for the failure of the last disk command, or the text of the
705 last Lisp error.
706
707 @item $=
708 A special associate array, which can take references of the form
709 @samp{$=[REGEXP]}. It indexes into the directory ring.
710 @end table
711
712 @item Eshell scripts can't execute in the background
713
714 @item Support zsh's ``Parameter Expansion'' syntax, i.e. @samp{$@{@var{name}:-@var{val}@}}
715
716 @item Write an @command{info} alias that can take arguments
717
718 So that the user can enter @samp{info chmod}, for example.
719
720 @item Create a mode @code{eshell-browse}
721
722 It would treat the Eshell buffer as a outline. Collapsing the outline
723 hides all of the output text. Collapsing again would show only the
724 first command run in each directory
725
726 @item Allow other revisions of a file to be referenced using @samp{file@{rev@}}
727
728 This 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
736 If it's a Lisp function, input redirection implies @command{xargs} (in a
737 way@dots{}). If input redirection is added, also update the
738 @code{file-name-quote-list}, and the delimiter list.
739
740 @item Allow @samp{#<@var{word} @var{arg}>} as a generic syntax
741
742 With the handling of @emph{word} specified by an
743 @code{eshell-special-alist}.
744
745 @item In @code{eshell-veal-using-options}, allow a @code{:complete} tag
746
747 It would be used to provide completion rules for that command. Then the
748 macro will automagically define the completion function.
749
750 @item For @code{eshell-command-on-region}, apply redirections to the result
751
752 So that @samp{+ > 'blah} would cause the result of the @code{+} (using
753 input from the current region) to be inserting into the symbol
754 @code{blah}.
755
756 If an external command is being invoked, the input is sent as standard
757 input, as if a @samp{cat <region> |} had been invoked.
758
759 If a Lisp command, or an alias, is invoked, then if the line has no
760 newline characters, it is divided by whitespace and passed as arguments
761 to the Lisp function. Otherwise, it is divided at the newline
762 characters. Thus, invoking @code{+} on a series of numbers will add
763 them; @code{min} would display the smallest figure, etc.
764
765 @item Write @code{eshell-script-mode} as a minor mode
766
767 It 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
772 This means @samp{!n}, @samp{!#}, @samp{!:%}, and @samp{!:1-} as separate
773 from @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
781 @item Implement @samp{>@var{func-or-func-list}}
782
783 This would allow for an ``output translators'', that take a function to
784 modify output with, and a target. Devise a syntax that works well with
785 pipes, and can accommodate multiple functions (i.e., @samp{>'(upcase
786 regexp-quote)} or @samp{>'upcase}).
787
788 @item Allow Eshell to read/write to/from standard input and output
789
790 This would be optional, rather than always using the Eshell buffer.
791 This would allow it to be run from the command line (perhaps).
792
793 @item Write a @command{help} command
794
795 It would call subcommands with @option{--help}, or @option{-h} or
796 @option{/?}, as appropriate.
797
798 @item Implement @command{stty} in Lisp
799
800 @item Support @command{rc}'s matching operator, e.g. @samp{~ (@var{list}) @var{regexp}}
801
802 @item Implement @command{bg} and @command{fg} as editors of @code{eshell-process-list}
803
804 Using @command{bg} on a process that is already in the background does
805 nothing. Specifying redirection targets replaces (or adds) to the list
806 current 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
814 The syntax table for parsing these should be customizable, such that the
815 user 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{$x[*]} equal to listing out the full contents of @samp{x}
820
821 Return them as a list, so that @samp{$_[*]} is all the arguments of the
822 last command.
823
824 @item Copy ANSI code handling from @file{term.el} into @file{em-term.el}
825
826 Make it possible for the user to send char-by-char to the underlying
827 process. Ultimately, I should be able to move away from using term.el
828 altogether, since everything but the ANSI code handling is already part
829 of 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
831 it).
832
833 @item Make the shell spawning commands be visual
834
835 That 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
838 being used to invoke a single command. Then, the behavior should be
839 based on what that command is.
840
841 @item Create a smart viewing command named @command{open}
842
843 This would search for some way to open its argument (similar to opening
844 a 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
850 It would move point to the end of the buffer, and then turns on
851 auto-revert mode in that buffer at frequent intervals---and a
852 @command{head} alias which assumes an upper limit of
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
857 @item Write mesh.c
858
859 This would run Emacs with the appropriate arguments to invoke Eshell
860 only. 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
870 So that it automatically expands and corrects pathnames. Or make
871 pathname 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
880 Add 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
890 This would call @code{ediff-patch-file}, or @code{ediff-patch-buffer},
891 depending 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
897 That is, @samp{find X | xargs Y} would be indicated using @samp{Y
898 $@{find X@}}. Maybe @code{eshell-do-pipelines} could be changed to
899 perform this on-thy-fly rewriting.
900
901 @item Write an alias for @command{less} that brings up a @code{view-mode} buffer
902
903 Such that the user can press @key{SPC} and @key{DEL}, and then @key{q}
904 to return to Eshell. It would be equivalent to:
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
909 Everywhere 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
916 If 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
918 eshell}, it doesn't display anything.
919
920 @item @kbd{M-RET} during a long command (using smart display) doesn't work
921
922 Since it keeps the cursor up where the command was invoked.
923
924 @end table
925
926 @node GNU Free Documentation License
927 @appendix GNU Free Documentation License
928 @include doclicense.texi
929
930 @node Concept Index
931 @unnumbered Concept Index
932
933 @printindex cp
934
935 @node Function and Variable Index
936 @unnumbered Function and Variable Index
937
938 @printindex fn
939
940 @node Key Index
941 @unnumbered Key Index
942
943 @printindex ky
944 @bye
945
946 @ignore
947 arch-tag: 776409ba-cb15-42b9-b2b6-d2bdc7ebad01
948 @end ignore