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(emacs)MS-DOS Processes

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Subprocesses on MS-DOS
======================

   Because MS-DOS is a single-process "operating system," asynchronous
subprocesses are not available.  In particular, Shell mode and its
variants do not work.  Most Emacs features that use asynchronous
subprocesses also don't work on MS-DOS, including Shell mode and GUD.
When in doubt, try and see; commands that don't work output an error
message saying that asynchronous processes aren't supported.

   Compilation under Emacs with `M-x compile', searching files with
`M-x grep' and displaying differences between files with `M-x diff' do
work, by running the inferior processes synchronously.  This means you
cannot do any more editing until the inferior process finishes.

   Spell checking also works, by means of special support for
synchronous invocation of the `ispell' program.  This is slower than the
asynchronous invocation on other platforms

   Instead of the Shell mode, which doesn't work on MS-DOS, you can use
the `M-x eshell' command.  This invokes the Eshell package that
implements a Posix-like shell entirely in Emacs Lisp.

   By contrast, Emacs compiled as native Windows application *does*
support asynchronous subprocesses.  Note: Windows Processes.

   Printing commands, such as `lpr-buffer' (Note: Hardcopy) and
`ps-print-buffer' (Note: PostScript), work in MS-DOS by sending the
output to one of the printer ports.  Note: MS-DOS Printing.

   When you run a subprocess synchronously on MS-DOS, make sure the
program terminates and does not try to read keyboard input.  If the
program does not terminate on its own, you will be unable to terminate
it, because MS-DOS provides no general way to terminate a process.
Pressing `C-c' or `C-<BREAK>' might sometimes help in these cases.

   Accessing files on other machines is not supported on MS-DOS.  Other
network-oriented commands such as sending mail, Web browsing, remote
login, etc., don't work either, unless network access is built into
MS-DOS with some network redirector.

   Dired on MS-DOS uses the `ls-lisp' package where other platforms use
the system `ls' command.  Therefore, Dired on MS-DOS supports only some
of the possible options you can mention in the `dired-listing-switches'
variable.  The options that work are `-A', `-a', `-c', `-i', `-r', `-S',
`-s', `-t', and `-u'.