@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999
-@c Free Software Foundation, Inc.
+@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/processes
@node Processes, Display, Abbrevs, Top
* Input to Processes:: Sending input to an asynchronous subprocess.
* Signals to Processes:: Stopping, continuing or interrupting
an asynchronous subprocess.
-* Query Before Exit:: Whether to query if exiting will kill a process.
* Output from Processes:: Collecting output from an asynchronous subprocess.
* Sentinels:: Sentinels run when process run-status changes.
+* Query Before Exit:: Whether to query if exiting will kill a process.
* Transaction Queues:: Transaction-based communication with subprocesses.
* Network:: Opening network connections.
@end menu
specify overrides for it with @code{process-environment}. @xref{System
Environment}.
-@defvar exec-directory
+@defvar exec-directory
@pindex movemail
The value of this variable is a string, the name of a directory that
contains programs that come with GNU Emacs, programs intended for Emacs
@smallexample
@group
-(call-process-region
- start end
+(call-process-region
+ start end
shell-file-name ; @r{Name of program.}
nil ; @r{Do not delete region.}
buffer ; @r{Send output to @code{buffer}.}
addition, the total number of @sc{pty}s is limited on many systems and
it is good not to waste them.
-The value of @code{process-connection-type} is used when
+The value of @code{process-connection-type} takes effect when
@code{start-process} is called. So you can specify how to communicate
with one subprocess by binding the variable around the call to
@code{start-process}.
but not necessarily right away. You can delete a process explicitly
at any time. If you delete a terminated process explicitly before it
is deleted automatically, no harm results. Deletion of a running
-process sends a signal to terminate it and calls the process sentinel
-if it has one.
+process sends a signal to terminate it (and its child processes if
+any), and calls the process sentinel if it has one.
@code{get-buffer-process} and @code{process-list} do not remember a
deleted process, but the process object itself continues to exist as
to send; it should be an integer.
@end defun
-@node Query Before Exit
-@section Querying Before Exit
-
- When Emacs exits, it terminates all its subprocesses by sending them
-the @code{SIGHUP} signal. Because some subprocesses are doing
-valuable work, Emacs normally asks the user to confirm that it is ok
-to terminate them. Each process has a query flag which, if
-non-@code{nil}, says that Emacs should ask for confirmation before
-exiting and thus killing that process. The default for the query flag
-is @code{t}, meaning @emph{do} query.
-
-@tindex process-query-on-exit-flag
-@defun process-query-on-exit-flag process
-This returns the query flag of @var{process}.
-@end defun
-
-@tindex set-process-query-on-exit-flag
-@defun set-process-query-on-exit-flag process flag
-This function sets the query flag of @var{process} to @var{flag}. It
-returns @var{flag}.
-
-@smallexample
-@group
-;; @r{Don't query about the shell process}
-(set-process-query-on-exit-flag (get-process "shell") nil)
- @result{} t
-@end group
-@end smallexample
-@end defun
-
-@defun process-kill-without-query process &optional do-query
-This function clears the query flag of @var{process}, so that
-Emacs will not query the user on account of that process.
-
-Actually, the function does more than that: it returns the old value of
-the process's query flag, and sets the query flag to @var{do-query}.
-Please don't use this function to do those things any more---please
-use the newer, cleaner functions @code{process-query-on-exit-flag} and
-@code{set-process-query-on-exit-flag} in all but the simplest cases.
-The only way you should use @code{process-kill-without-query} nowadays
-is like this:
-
-@smallexample
-@group
-;; @r{Don't query about the shell process}
-(process-kill-without-query (get-process "shell"))
-@end group
-@end smallexample
-@end defun
-
@node Output from Processes
@section Receiving Output from Processes
@cindex process output
called the @dfn{filter function} can be called to act on the output. If
the process has no buffer and no filter function, its output is
discarded.
-
+
+ When a subprocess terminates, Emacs reads any pending output,
+then stops reading output from that subprocess. Therefore, if the
+subprocess has children that are still live and still producing
+output, Emacs won't receive that output.
+
Output from a subprocess can arrive only while Emacs is waiting: when
reading terminal input, in @code{sit-for} and @code{sleep-for}
(@pxref{Waiting}), and in @code{accept-process-output} (@pxref{Accepting
The string describing the event looks like one of the following:
@itemize @bullet
-@item
+@item
@code{"finished\n"}.
@item
off. This makes it possible to use the Lisp debugger to debug the
sentinel. @xref{Debugger}.
+ While a sentinel is running, the process sentinel is temporarily
+set to @code{nil} so that the sentinel won't run recursively.
+For this reason it is not possible for a sentinel to specify
+a new sentinel.
+
In earlier Emacs versions, every sentinel that did regular expression
searching or matching had to explicitly save and restore the match data.
Now Emacs does this automatically for sentinels; they never need to do
was not.
@end defun
+@node Query Before Exit
+@section Querying Before Exit
+
+ When Emacs exits, it terminates all its subprocesses by sending them
+the @code{SIGHUP} signal. Because some subprocesses are doing
+valuable work, Emacs normally asks the user to confirm that it is ok
+to terminate them. Each process has a query flag which, if
+non-@code{nil}, says that Emacs should ask for confirmation before
+exiting and thus killing that process. The default for the query flag
+is @code{t}, meaning @emph{do} query.
+
+@tindex process-query-on-exit-flag
+@defun process-query-on-exit-flag process
+This returns the query flag of @var{process}.
+@end defun
+
+@tindex set-process-query-on-exit-flag
+@defun set-process-query-on-exit-flag process flag
+This function sets the query flag of @var{process} to @var{flag}. It
+returns @var{flag}.
+
+@smallexample
+@group
+;; @r{Don't query about the shell process}
+(set-process-query-on-exit-flag (get-process "shell") nil)
+ @result{} t
+@end group
+@end smallexample
+@end defun
+
+@defun process-kill-without-query process &optional do-query
+This function clears the query flag of @var{process}, so that
+Emacs will not query the user on account of that process.
+
+Actually, the function does more than that: it returns the old value of
+the process's query flag, and sets the query flag to @var{do-query}.
+Please don't use this function to do those things any more---please
+use the newer, cleaner functions @code{process-query-on-exit-flag} and
+@code{set-process-query-on-exit-flag} in all but the simplest cases.
+The only way you should use @code{process-kill-without-query} nowadays
+is like this:
+
+@smallexample
+@group
+;; @r{Don't query about the shell process}
+(process-kill-without-query (get-process "shell"))
+@end group
+@end smallexample
+@end defun
+
@node Transaction Queues
@section Transaction Queues
@cindex transaction queue