eshell   [plain text]


This is ../info/eshell, produced by makeinfo version 4.0 from
eshell.texi.

INFO-DIR-SECTION Emacs
START-INFO-DIR-ENTRY
* Eshell: (eshell).     A command shell implemented in Emacs Lisp.
END-INFO-DIR-ENTRY

   Copyright (C) 1999, 2000, 2001  Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with the Front-Cover texts being "A GNU Manual",
and with the Back-Cover Texts as in (a) below.  A copy of the license
is included in the section entitled "GNU Free Documentation License" in
the Emacs manual.

   (a) The FSF's Back-Cover Text is: "You have freedom to copy and
modify this GNU Manual, like GNU software.  Copies published by the Free
Software Foundation raise funds for GNU development."

   This document is part of a collection distributed under the GNU Free
Documentation License.  If you want to distribute this document
separately from the collection, you can do so by adding a copy of the
license to the document, as described in section 6 of the license.


File: eshell,  Node: Top,  Next: What is Eshell?,  Prev: (dir),  Up: (dir)

Eshell
******

   This manual documents Eshell, a shell-like command interpretor
implemented in Emacs Lisp.  It invokes no external processes except for
those requested by the user.  It is intended to be a functional
replacement for command shells such as `bash', `zsh', `rc', or `4dos';
since Emacs itself is capable of handling the sort of tasks
accomplished by those tools.

* Menu:

* What is Eshell?::             A brief introduction to the Emacs Shell.
* Installation::                For users of Emacs 20 and XEmacs.
* Command basics::              The basics of command usage.
* Commands::
* Arguments::
* Input/Output::
* Process control::
* Extension modules::
* Extras and Goodies::
* Bugs and ideas::              Known problems, and future ideas.
* Concept Index::
* Function and Variable Index::
* Key Index::


File: eshell,  Node: What is Eshell?,  Next: Installation,  Prev: Top,  Up: Top

What is Eshell?
***************

   Eshell is a "command shell" written in Emacs Lisp.  Everything it
does, it uses Emacs' facilities to do.  This means that Eshell is as
portable as Emacs itself.  It also means that cooperation with Lisp code
is natural and seamless.

   What is a command shell?  To properly understand the role of a shell,
it's necessary to visualize what a computer does for you.  Basically, a
computer is a tool; in order to use that tool, you must tell it what to
do--or give it "commands."  These commands take many forms, such as
clicking with a mouse on certain parts of the screen.  But that is only
one form of command input.

   By far the most versatile way to express what you want the computer
to do is by using an abbreviated language called "script".  In script,
instead of telling the computer, "list my files, please", one writes a
standard abbreviated command word--`ls'.  Typing `ls' in a command
shell is a script way of telling the computer to list your files.(1)

   The real flexibility of this approach is apparent only when you
realize that there are many, many different ways to list files.
Perhaps you want them sorted by name, sorted by date, in reverse order,
or grouped by type.  Most graphical browsers have simple ways to
express this.  But what about showing only a few files, or only files
that meet a certain criteria?  In very complex and specific situations,
the request becomes too difficult to express using a mouse or pointing
device.  It is just these kinds of requests that are easily solved
using a command shell.

   For example, what if you want to list every Word file on your hard
drive, larger than 100 kilobytes in size, and which hasn't been looked
at in over six months?  That is a good candidate list for deletion, when
you go to clean up your hard drive.  But have you ever tried asking your
computer for such a list?  There is no way to do it!  At least, not
without using a command shell.

   The role of a command shell is to give you more control over what
your computer does for you.  Not everyone needs this amount of control,
and it does come at a cost: Learning the necessary script commands to
express what you want done.  A complicated query, such as the example
above, takes time to learn.  But if you find yourself using your
computer frequently enough, it is more than worthwhile in the long run.
Any tool you use often deserves the time spent learning to master it.
(2)

   As of Emacs 21, Eshell is part of the standard Emacs distribution.

* Menu:

* Contributors to Eshell::      People who have helped out!

   ---------- Footnotes ----------

   (1) This is comparable to viewing the contents of a folder using a
graphical display.

   (2) For the understandably curious, here is what that command looks
like: But don't let it fool you; once you know what's going on, it's
easier than it looks: `ls -lt **/*.doc(Lk+50aM+5)'.


File: eshell,  Node: Contributors to Eshell,  Prev: What is Eshell?,  Up: What is Eshell?

Contributors to Eshell
======================

   Contributions to Eshell are welcome.  I have limited time to work on
this project, but I will gladly add any code you contribute to me to
this package.

   The following persons have made contributions to Eshell.

   * Eli Zaretskii made it possible for Eshell to run without requiring
     asynchronous subprocess support.  This is important for MS-DOS,
     which does not have such support.

   * Miles Bader contributed many fixes during the port to Emacs 21.

   * Stefan Monnier fixed the things which bothered him, which of
     course made things better for all.

   * Gerd Moellmann also helped to contribute bug fixes during the
     initial integration with Emacs 21.

   * Alex Schroeder contributed code for interactively querying the user
     before overwriting files.

   * Sudish Joseph helped with some XEmacs compatibility issues.

   Apart from these, a lot of people have sent suggestions, ideas,
requests, bug reports and encouragement.  Thanks a lot!  Without you
there would be no new releases of Eshell.


File: eshell,  Node: Installation,  Next: Command basics,  Prev: What is Eshell?,  Up: Top

Installation
************

   As mentioned above, Eshell comes preinstalled as of Emacs 21.  If
you're using Emacs 20.4 or later, or XEmacs 21, you can download the
most recent version of Eshell from
<http://www.gci-net.com/users/j/johnw/Emacs/eshell.tar.gz>.

   However, if you are using Emacs 21, you may skip this section.

Short Form
==========

   Here's exactly what to do, with no explanation why:

  1. `M-x load-file RET eshell-auto.el RET'.

  2. `ESC : (add-to-list 'load-path "<path where Eshell resides>") RET'.

  3. `ESC : (add-to-list 'load-path "<path where Pcomplete resides>")
     RET'.

  4. `M-x eshell RET'.

     You should see a version banner displayed.

  5. `ls RET'.

     Confirm that you see a file listing.

  6. `eshell-test RET'.

     Confirm that everything runs correctly.  Use `M-x
     eshell-report-bug' if not.

  7. `cd ${dirname (locate-library "eshell-auto")} RET'.

  8. `find-file Makefile RET'.

  9. Edit the Makefile to reflect your site.

 10. `M-x eshell RET'.

 11. `make install RET'.

 12. `find-file $user-init-file RET'.

 13. Add the following lines to your `.emacs' file:

          (add-to-list 'load-path "<directory where you install Eshell>")
          (load "eshell-auto")

 14. `M-x eshell RET'.

 15. `customize-option #'eshell-modules-list RET'.

 16. Select the extension modules you prefer.

 17. Restart Emacs!

 18. `M-x info RET m Eshell RET'.

     Read the manual and enjoy!

Long Form
=========

  1. Before building and installing Eshell, it is important to test
     that it will work properly on your system.  To do this, first load
     the file `eshell-auto', which will define certain autoloads
     required to run Eshell.  This can be done using the command `M-x
     load-file', and then selecting the file `eshell-auto.el'.

  2. In order for Emacs to find Eshell's files, the Eshell directory
     must be added to the `load-path' variable.  This can be done
     within Emacs by typing:

          ESC : (add-to-list 'load-path "<path where Eshell resides>") RET
          ESC : (add-to-list 'load-path "<path where Pcomplete resides>") RET

  3. Start Eshell from the distributed sources, using default settings,
     by typing `M-x eshell'.

  4. Verify that Eshell is functional by typing `ls' followed by <RET>.
     You should have already seen a version banner announcing the
     version number of this release, followed by a prompt.

  5. Run the test suite by typing `eshell-test' followed by <RET> in
     the Eshell buffer.  It is important that Emacs be left alone while
     the tests are running, since extraneous command input may cause
     some of the tests to fail (they were never intended to run in the
     background).  If all of the tests pass, Eshell should work just
     fine on your system.  If any of the tests fail, please send e-mail
     to the Eshell maintainer using the command `M-x eshell-report-bug'.

  6. Edit the file `Makefile' in the directory containing the Eshell
     sources to reflect the location of certain Emacs directories at
     your site.  The only things you really have to change are the
     definitions of `lispdir' and `infodir'.  The elisp files will be
     copied to `lispdir', and the info file to `infodir'.

  7. Type `make install' in the directory containing the Eshell sources.
     This will byte-compile all of the `*.el' files and copy both the
     source and compiled versions to the directories specified in the
     previous step.  It will also copy the info file, and add a
     corresponding entry to your `dir' file---if the program
     `install-info' can be found on your system.

     If you only want to create the compiled elisp files, but don't
     want to install them, you can type just `make' instead.

  8. Add the directory into which Eshell was installed to your
     `load-path' variable.  This can be done by adding the following
     line to your `.emacs' file:

          (add-to-list 'load-path "/usr/local/share/emacs/site-lisp/eshell")

     The actual directory on your system may differ.

  9. To install Eshell privately, edit your `.emacs' file; to install
     Eshell site-wide, edit the file `site-start.el' in your
     `site-lisp' directory (usually `/usr/local/share/emacs/site-lisp'
     or something similar).  In either case enter the following line
     into the appropriate file:

          (load "eshell-auto")

 10. Restart Emacs.  After restarting, customize the variable
     `eshell-modules-list'.  This variable selects which Eshell
     extension modules you want to use.  You will find documentation on
     each of those modules in the Info manual.

   If you have TeX installed at your site, you can make a typeset manual
from `eshell.texi'.

  1. Run TeX by typing `texi2dvi eshell.texi'.  (With Emacs 21.1 or
     later, typing `make eshell.dvi' in the `man/' subdirectory of the
     Emacs source distribution will do that.)

  2. Convert the resulting device independent file `eshell.dvi' to a
     form which your printer can output and print it.  If you have a
     postscript printer, there is a program, `dvi2ps', which does that;
     there is also a program which comes together with TeX, `dvips',
     which you can use.  For other printers, use a suitable DVI driver,
     e.g., `dvilj4' for LaserJet-compatible printers.


File: eshell,  Node: Command basics,  Next: Commands,  Prev: Installation,  Up: Top

Basic overview
**************

   A command shell is a means of entering verbally-formed commands.
This is really all that it does, and every feature described in this
manual is a means to that end.  Therefore, it's important to take firm
hold on exactly what a command is, and how it fits in the overall
picture of things.

* Menu:

* Commands verbs::              Commands always begin with a verb.
* Command arguments::           Some verbs require arguments.


File: eshell,  Node: Commands verbs,  Next: Command arguments,  Prev: Command basics,  Up: Command basics

Commands verbs
==============

   Commands are expressed using "script", a special shorthand language
computers can understand with no trouble.  Script is an extremely simple
language; oddly enough, this is what makes it look so complicated!
Whereas normal languages use a variety of embellishments, the form of a
script command is always:

     VERB [ARGUMENTS]

   The verb expresses what you want your computer to do.  There are a
fixed number of verbs, although this number is usually quite large.  On
the author's computer, it reaches almost 1400 in number.  But of course,
only a handful of these are really necessary.

   Sometimes, the verb is all that's written.  A verb is always a single
word, usually related to the task it performs.  `reboot' is a good
example.  Entering that on GNU/Linux will reboot the computer--assuming
you have sufficient privileges.

   Other verbs require more information.  These are usually very capable
verbs, and must be told specifically what to do.  The extra information
is given in the form of "arguments".  For example, the `echo' verb
prints back whatever arguments you type.  It requires these arguments
to know what to echo.  A proper use of `echo' looks like this:

     echo This is an example of using echo!

   This script command causes the computer to echo back: "This is an
example of using echo!"

   Although command verbs are always simple words, like `reboot' or
`echo', arguments may have a wide variety of forms.  There are textual
arguments, numerical arguments--even Lisp arguments.  Distinguishing
these different types of arguments requires special typing, for the
computer to know exactly what you mean.


File: eshell,  Node: Command arguments,  Prev: Commands verbs,  Up: Command basics

Command arguments
=================

   Eshell recognizes several different kinds of command arguments:

  1. Strings (also called textual arguments)

  2. Numbers (floating point or integer)

  3. Lisp lists

  4. Lisp symbols

  5. Emacs buffers

  6. Emacs process handles

   Most users need to worry only about the first two.  The third, Lisp
lists, occur very frequently, but almost always behind the scenes.

   Strings are the most common type of argument, and consist of nearly
any character.  Special characters--those used by Eshell
specifically--must be preceded by a backslash (`\').  When in doubt, it
is safe to add backslashes anywhere and everywhere.

   Here is a more complicated `echo' example:

     echo A\ Multi-word\ Argument\ With\ A\ \$\ dollar

   Beyond this, things get a bit more complicated.  While not beyond the
reach of someone wishing to learn, it is definitely beyond the scope of
this manual to present it all in a simplistic manner.  Get comfortable
with Eshell as a basic command invocation tool, and learn more about the
commands on your system; then come back when it all sits more familiarly
on your mind.  Have fun!


File: eshell,  Node: Commands,  Next: Arguments,  Prev: Command basics,  Up: Top

Commands
********

* Menu:

* Invocation::
* Completion::
* Aliases::
* History::
* Scripts::

   Essentially, a command shell is all about invoking commands--and
everything that entails.  So understanding how Eshell invokes commands
is the key to comprehending how it all works.


File: eshell,  Node: Invocation,  Next: Completion,  Prev: Commands,  Up: Commands

Invocation
==========

   Unlike regular system shells, Eshell never invokes kernel functions
directly, such as `exec(3)'.  Instead, it uses the Lisp functions
available in the Emacs Lisp library.  It does this by transforming the
command you specify into a callable Lisp form.(1)

   This transformation, from the string of text typed at the command
prompt, to the ultimate invocation of either a Lisp function or external
command, follows these steps:

  1. Parse the command string into separate arguments.

  2.
   ---------- Footnotes ----------

   (1) To see the Lisp form that will be invoked, type:
`eshell-parse-command "echo hello"'


File: eshell,  Node: Completion,  Next: Aliases,  Prev: Invocation,  Up: Commands

Completion
==========


File: eshell,  Node: Aliases,  Next: History,  Prev: Completion,  Up: Commands

Aliases
=======


File: eshell,  Node: History,  Next: Scripts,  Prev: Aliases,  Up: Commands

History
=======


File: eshell,  Node: Scripts,  Prev: History,  Up: Commands

Scripts
=======


File: eshell,  Node: Arguments,  Next: Input/Output,  Prev: Commands,  Up: Top

Arguments
*********

* Menu:

* The Parser::
* Variables::
* Substitution::
* Globbing::
* Predicates::


File: eshell,  Node: The Parser,  Next: Variables,  Prev: Arguments,  Up: Arguments

The Parser
==========


File: eshell,  Node: Variables,  Next: Substitution,  Prev: The Parser,  Up: Arguments

Variables
=========


File: eshell,  Node: Substitution,  Next: Globbing,  Prev: Variables,  Up: Arguments

Substitution
============


File: eshell,  Node: Globbing,  Next: Predicates,  Prev: Substitution,  Up: Arguments

Globbing
========


File: eshell,  Node: Predicates,  Prev: Globbing,  Up: Arguments

Predicates
==========


File: eshell,  Node: Input/Output,  Next: Process control,  Prev: Arguments,  Up: Top

Input/Output
************


File: eshell,  Node: Process control,  Next: Extension modules,  Prev: Input/Output,  Up: Top

Process control
***************


File: eshell,  Node: Extension modules,  Next: Extras and Goodies,  Prev: Process control,  Up: Top

Extension modules
*****************

* Menu:

* Writing a module::
* Module testing::
* Directory handling::
* Key rebinding::
* Smart scrolling::
* Terminal emulation::
* Built-in UNIX commands::


File: eshell,  Node: Writing a module,  Next: Module testing,  Prev: Extension modules,  Up: Extension modules

Writing a module
================


File: eshell,  Node: Module testing,  Next: Directory handling,  Prev: Writing a module,  Up: Extension modules

Module testing
==============


File: eshell,  Node: Directory handling,  Next: Key rebinding,  Prev: Module testing,  Up: Extension modules

Directory handling
==================


File: eshell,  Node: Key rebinding,  Next: Smart scrolling,  Prev: Directory handling,  Up: Extension modules

Key rebinding
=============


File: eshell,  Node: Smart scrolling,  Next: Terminal emulation,  Prev: Key rebinding,  Up: Extension modules

Smart scrolling
===============


File: eshell,  Node: Terminal emulation,  Next: Built-in UNIX commands,  Prev: Smart scrolling,  Up: Extension modules

Terminal emulation
==================


File: eshell,  Node: Built-in UNIX commands,  Prev: Terminal emulation,  Up: Extension modules

Built-in UNIX commands
======================


File: eshell,  Node: Extras and Goodies,  Next: Bugs and ideas,  Prev: Extension modules,  Up: Top

Extras and Goodies
******************


File: eshell,  Node: Bugs and ideas,  Next: Concept Index,  Prev: Extras and Goodies,  Up: Top

Bugs and ideas
**************

   If you find a bug or misfeature, don't hesitate to let me know!  Send
email to <johnw@gnu.org>.  Feature requests should also be sent there.
I prefer discussing one thing at a time.  If you find several unrelated
bugs, please report them separately.

   If you have ideas for improvements, or if you have written some
extensions to this package, I would like to hear from you.  I hope you
find this package useful!

* Menu:

* Known problems::


File: eshell,  Node: Known problems,  Prev: Bugs and ideas,  Up: Bugs and ideas

Known problems
==============

   Below is complete list of known problems with Eshell version 2.4.1,
which is the version included with Emacs 21.1.

Differentiate between aliases and functions
     Allow for a bash-compatible syntax, such as:

          alias arg=blah
          function arg () { blah $* }

`for i in 1 2 3 { grep -q a b && *echo has it } | wc -l' outputs result after prompt
     In fact, piping to a process from a looping construct doesn't work
     in general.  If I change the call to `eshell-copy-handles' in
     `eshell-rewrite-for-command' to use `eshell-protect', it seems to
     work, but the output occurs after the prompt is displayed.  The
     whole structured command thing is too complicated at present.

Error with `bc' in `eshell-test'
     On some XEmacs system, the subprocess interaction test fails
     inexplicably, although `bc' works fine at the command prompt.

Eshell does not delete `*Help*' buffers in XEmacs 21.1.8+
     In XEmacs 21.1.8, the `*Help*' buffer has been renamed such that
     multiple instances of the `*Help*' buffer can exist.

Pcomplete sometimes gets stuck
     You press <TAB>, but no completions appear, even though the
     directory has matching files.  This behavior is rare.

`grep python $<rpm -qa>' doesn't work, but using `*grep' does
     This happens because the `grep' Lisp function returns immediately,
     and then the asynchronous `grep' process expects to examine the
     temporary file, which has since been deleted.

Problem with C-r repeating text
     If the text _before point_ reads "./run", and you type `C-r r u
     n', it will repeat the line for every character typed.

Backspace doesn't scroll back after continuing (in smart mode)
     Hitting space during a process invocation, such as `make', will
     cause it to track the bottom of the output; but backspace no longer
     scrolls back.

It's not possible to fully `unload-feature' Eshell

Menu support was removed, but never put back

Using C-p and C-n with rebind gets into a locked state
     This happened a few times in Emacs 21, but has been unreproducable
     since.

If an interactive process is currently running, `M-!' doesn't work

Use a timer instead of `sleep-for' when killing child processes

Piping to a Lisp function is not supported
     Make it so that the Lisp command on the right of the pipe is
     repeatedly called with the input strings as arguments.  This will
     require changing `eshell-do-pipeline' to handle non-process
     targets.

Input redirection is not supported
     See the above entry.

Problem running `less' without arguments on Windows
     The result in the Eshell buffer is:

          Spawning child process: invalid argument

     Also a new `less' buffer was created with nothing in it...
     (presumably this holds the output of `less').

     If `less.exe' is invoked from the Eshell command line, the
     expected output is written to the buffer.

     Note that this happens on NT-Emacs 20.6.1 on Windows 2000. The
     term.el package and the supplied shell both use the `cmdproxy'
     program for running shells.

Implement `-r', `-n' and `-s' switches for `cp'

Make `M-5 M-x eshell' switch to "*eshell<5>*", creating if need be

`mv DIR FILE.tar' does not remove directories
     This is because the tar option -remove-files doesn't do so.
     Should it be Eshell's job?

Bind `standard-output' and `standard-error'
     This would be so that if a Lisp function calls `print', everything
     will happen as it should (albeit slowly).

When an extension module fails to load, `cd /' gives a Lisp error

If a globbing pattern returns one match, should it be a list?

Make sure syntax table is correct in Eshell mode
     So that `M-DEL' acts in a predictable manner, etc.

Allow all Eshell buffers to share the same history and list-dir

There is a problem with script commands that output to `/dev/null'
     If a script file, somewhere in the middle, uses `> /dev/null',
     output from all subsequent commands is swallowed.

Split up parsing of text after `$' in `esh-var.el'
     Make it similar to the way that `esh-arg.el' is structured.  Then
     add parsing of `$[?\n]'.

After pressing `M-RET', redisplay before running the next command

Argument predicates and modifiers should work anywhere in a path
          /usr/local/src/editors/vim $ vi **/CVS(/)/Root(.)
          Invalid regexp: "Unmatched ( or \\("

     With `zsh', the glob above expands to all files named `Root' in
     directories named `CVS'.

Typing `echo ${locate locate}/bin<TAB>' results in a Lisp error
     Perhaps it should interpolate all permutations, and make that the
     globbing result, since otherwise hitting return here will result in
     "(list of filenames)/bin", which is never valuable.  Thus, one
     could `cat' only C backup files by using `ls ${identity *.c}~'.
     In that case, having an alias command name `glob' for `identity'
     would be useful.

Once symbolic mode is supported for `umask', implement `chmod' in Lisp

Create `eshell-expand-file-name'
     This would use a data table to transform things such as `~+',
     `...', etc.

Abstract `em-smart.el' into `smart-scroll.el'
     It only really needs: to be hooked onto the output filter and the
     pre-command hook, and to have the input-end and input-start
     markers.  And to know whether the last output group was
     "successful."

Allow for fully persisting the state of Eshell
     This would include: variables, history, buffer, input, dir stack,
     etc.

Implement D as an argument predicate
     It means that files beginning with a dot should be included in the
     glob match.

A comma in a predicate list should mean OR
     At the moment, this is not supported.

Error if a glob doesn't expand due to a predicate
     An error should be generated only if `eshell-error-if-no-glob' is
     non-nil.

`(+ RET SPC TAB' does not cause `indent-according-to-mode' to occur

Create `eshell-auto-accumulate-list'
     This is a list of commands for which, if the user presses `RET',
     the text is staged as the next Eshell command, rather than being
     sent to the current interactive process.

Display file and line number if an error occurs in a script

`wait' doesn't work with process ids at the moment

Enable the direct-to-process input code in `em-term.el'

Problem with repeating `echo ${find /tmp}'
     With smart display active, if `RET' is held down, after a while it
     can't keep up anymore and starts outputting blank lines.  It only
     happens if an asynchronous process is involved...

     I think the problem is that `eshell-send-input' is resetting the
     input target location, so that if the asynchronous process is not
     done by the time the next `RET' is received, the input processor
     thinks that the input is meant for the process; which, when smart
     display is enabled, will be the text of the last command line!
     That is a bug in itself.

     In holding down `RET' while an asynchronous process is running,
     there will be a point in between termination of the process, and
     the running of `eshell-post-command-hook', which would cause
     `eshell-send-input' to call `eshell-copy-old-input', and then
     process that text as a command to be run after the process.
     Perhaps there should be a way of killing pending input between the
     death of the process, and the `post-command-hook'.

Allow for a more aggressive smart display mode
     Perhaps toggled by a command, that makes each output block a smart
     display block.

Create more meta variables

    `$!'
          The reason for the failure of the last disk command, or the
          text of the last Lisp error.

    `$='
          A special associate array, which can take references of the
          form `$=[REGEXP]'.  It indexes into the directory ring.

Eshell scripts can't execute in the background

Support zsh's "Parameter Expansion" syntax, i.e. `${NAME:-VAL}'

Write an `info' alias that can take arguments
     So that the user can enter `info chmod', for example.

Create a mode `eshell-browse'
     It would treat the Eshell buffer as a outline.  Collapsing the
     outline hides all of the output text.  Collapsing again would show
     only the first command run in each directory

Allow other revisions of a file to be referenced using `file{rev}'
     This would be expanded by `eshell-expand-file-name' (see above).

Print "You have new mail" when the "Mail" icon is turned on

Implement `M-|' for Eshell

Implement input redirection
     If it's a Lisp function, input redirection implies `xargs' (in a
     way...).  If input redirection is added, also update the
     `file-name-quote-list', and the delimiter list.

Allow `#<WORD ARG>' as a generic syntax
     With the handling of _word_ specified by an `eshell-special-alist'.

In `eshell-veal-using-options', allow a `:complete' tag
     It would be used to provide completion rules for that command.
     Then the macro will automagically define the completion function.

For `eshell-command-on-region', apply redirections to the result
     So that `+ > 'blah' would cause the result of the `+' (using input
     from the current region) to be inserting into the symbol `blah'.

     If an external command is being invoked, the input is sent as
     standard input, as if a `cat <region> |' had been invoked.

     If a Lisp command, or an alias, is invoked, then if the line has no
     newline characters, it is divided by whitespace and passed as
     arguments to the Lisp function.  Otherwise, it is divided at the
     newline characters.  Thus, invoking `+' on a series of numbers
     will add them; `min' would display the smallest figure, etc.

Write `eshell-script-mode' as a minor mode
     It would provide syntax, abbrev, highlighting and indenting
     support like `emacs-lisp-mode' and `shell-mode'.

In the history mechanism, finish the `bash'-style support
     This means `!n', `!#', `!:%', and `!:1-' as separate from `!:1*'.

Support the -n command line option for `history'

Implement `fc' in Lisp

Specifying a frame as a redirection target should imply the currently active window's buffer

Implement `>FUNC-OR-FUNC-LIST'
     This would allow for an "output translators", that take a function
     to modify output with, and a target.  Devise a syntax that works
     well with pipes, and can accomodate multiple functions (i.e.,
     `>'(upcase regexp-quote)' or `>'upcase').

Allow Eshell to read/write to/from standard input and output
     This would be optional, rather than always using the Eshell buffer.
     This would allow it to be run from the command line (perhaps).

Write a `help' command
     It would call subcommands with `--help', or `-h' or `/?', as
     appropriate.

Implement `stty' in Lisp

Support `rc''s matching operator, e.g. `~ (LIST) REGEXP'

Implement `bg' and `fg' as editors of `eshell-process-list'
     Using `bg' on a process that is already in the background does
     nothing.  Specifying redirection targets replaces (or adds) to the
     list current being used.

Have `jobs' print only the processes for the current shell

How can Eshell learn if a background process has requested input?

Support `2>&1' and `>&' and `2>' and `|&'
     The syntax table for parsing these should be customizable, such
     that the user could change it to use rc syntax: `>[2=1]'.

Allow `$_[-1]', which would indicate the last element of the array

Make `$x[*]' equal to listing out the full contents of `x'
     Return them as a list, so that `$_[*]' is all the arguments of the
     last command.

Copy ANSI code handling from `term.el' into `em-term.el'
     Make it possible for the user to send char-by-char to the
     underlying process.  Ultimately, I should be able to move away
     from using term.el altogether, since everything but the ANSI code
     handling is already part of Eshell.  Then, things would work
     correctly on MS-Windows as well (which doesn't have `/bin/sh',
     although `term.el' tries to use it).

Make the shell spawning commands be visual
     That is, make (`su', `bash', `telnet', `rlogin', `rsh', etc.) be
     part of `eshell-visual-commands'.  The only exception is if the
     shell is being used to invoke a single command.  Then, the
     behavior should be based on what that command is.

Create a smart viewing command named `open'
     This would search for some way to open its argument (similar to
     opening a file in the Windows Explorer).

Alias `read' to be the same as `open', only read-only

Write a `tail' command which uses `view-file'
     It would move point to the end of the buffer, and then turns on
     auto-revert mode in that buffer at frequent intervals--and a
     `head' alias which assums an upper limit of
     `eshell-maximum-line-length' characters per line.

Make `dgrep' load `dired', mark everything, then invoke `dired-do-search'

Write mesh.c
     This would run Emacs with the appropriate arguments to invoke
     Eshell only.  That way, it could be listed as a login shell.

Use an intangible `PS2' string for multi-line input prompts

Auto-detect when a command is visual, by checking `TERMCAP' usage

The first keypress after `M-x watson' triggers `eshell-send-input'

Make `/' electric
     So that it automatically expands and corrects pathnames.  Or make
     pathname completion for Pcomplete auto-expand `/u/i/std<TAB>' to
     `/usr/include/std<TAB>'.

Write the `pushd' stack to disk along with `last-dir-ring'

Add options to `eshell/cat' which would allow it to sort and uniq

Implement `wc' in Lisp
     Add support for counting sentences, paragraphs, pages, etc.

Once piping is added, implement `sort' and `uniq' in Lisp

Implement `touch' in Lisp

Implement `comm' in Lisp

Implement an `epatch' command in Lisp
     This would call `ediff-patch-file', or `ediff-patch-buffer',
     depending on its argument.

Have an option such that `ls -l' generates a dired buffer

Write a version of `xargs' based on command rewriting
     That is, `find X | xargs Y' would be indicated using `Y ${find
     X}'.  Maybe `eshell-do-pipelines' could be changed to perform this
     on-thy-fly rewriting.

Write an alias for `less' that brings up a `view-mode' buffer
     Such that the user can press <SPC> and <DEL>, and then <q> to
     return to Eshell.  It would be equivalent to: `X > #<buffer Y>;
     view-buffer #<buffer Y>'.

Make `eshell-mode' as much a full citizen as `shell-mode'
     Everywhere in Emacs where `shell-mode' is specially noticed, add
     `eshell-mode' there.

Permit the umask to be selectively set on a `cp' target

Problem using `M-x eshell' after using `eshell-command'
     If the first thing that I do after entering Emacs is to run
     `eshell-command' and invoke `ls', and then use `M-x eshell', it
     doesn't display anything.

`M-RET' during a long command (using smart display) doesn't work
     Since it keeps the cursor up where the command was invoked.


File: eshell,  Node: Concept Index,  Next: Function and Variable Index,  Prev: Bugs and ideas,  Up: Top

Concept Index
*************

* Menu:

* author, how to reach:                  Bugs and ideas.
* authors:                               Contributors to Eshell.
* bugs, how to report them:              Bugs and ideas.
* bugs, known:                           Known problems.
* contributors:                          Contributors to Eshell.
* documentation, printed version:        Installation.
* email to the author:                   Bugs and ideas.
* Eshell, what it is:                    What is Eshell?.
* FAQ:                                   Bugs and ideas.
* installation:                          Installation.
* known bugs:                            Known problems.
* printed version of documentation:      Installation.
* problems, list of common:              Bugs and ideas.
* reporting bugs and ideas:              Bugs and ideas.
* what is Eshell?:                       What is Eshell?.


File: eshell,  Node: Function and Variable Index,  Next: Key Index,  Prev: Concept Index,  Up: Top

Function and Variable Index
***************************

* Menu:

File: eshell,  Node: Key Index,  Prev: Function and Variable Index,  Up: Top

Key Index
*********

* Menu:


Tag Table:
Node: Top1185
Node: What is Eshell?2090
Ref: What is Eshell?-Footnote-14807
Ref: What is Eshell?-Footnote-24897
Node: Contributors to Eshell5090
Node: Installation6263
Node: Command basics11700
Node: Commands verbs12251
Node: Command arguments14033
Node: Commands15279
Node: Invocation15644
Ref: Invocation-Footnote-116282
Node: Completion16375
Node: Aliases16483
Node: History16582
Node: Scripts16678
Node: Arguments16758
Node: The Parser16945
Node: Variables17055
Node: Substitution17166
Node: Globbing17281
Node: Predicates17389
Node: Input/Output17480
Node: Process control17596
Node: Extension modules17726
Node: Writing a module18027
Node: Module testing18176
Node: Directory handling18322
Node: Key rebinding18473
Node: Smart scrolling18615
Node: Terminal emulation18761
Node: Built-in UNIX commands18922
Node: Extras and Goodies19067
Node: Bugs and ideas19208
Node: Known problems19785
Node: Concept Index34923
Node: Function and Variable Index35936
Node: Key Index36103

End Tag Table