GNU Info

Info Node: (eshell)Known problems

(eshell)Known problems


Prev: Bugs and ideas Up: Bugs and ideas
Enter node , (file) or (file)node

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

   Below is complete list of known problems with Eshell version 2.4.2,
which is the version included with Emacs 21.2.

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.


automatically generated by info2www version 1.2.2.9