@ref{Asynchronous Processes}).
@end defun
-@anchor{Coding systems for a subprocess}
@defun process-coding-system process
+@anchor{Coding systems for a subprocess}
This function returns a cons cell describing the coding systems in use
for decoding output from @var{process} and for encoding input to
@var{process} (@pxref{Coding Systems}). The value has this form:
can arrive before you finish, if the code in between does not call any
primitive that waits.
+@defvar process-adaptive-read-buffering
+On some systems, when Emacs reads the output from a subprocess, the
+output data is read in very small blocks, potentially resulting in
+very poor performance. This behaviour can be remedied to some extent
+by setting the variable @var{process-adaptive-read-buffering} to a
+non-nil value (the default), as it will automatically delay reading
+from such processes, thus allowing them to produce more output before
+Emacs tries to read it.
+@end defvar
+
It is impossible to separate the standard output and standard error
streams of the subprocess, because Emacs normally spawns the subprocess
inside a pseudo-TTY, and a pseudo-TTY has only one output channel. If
you want to keep the output to those streams separate, you should
-redirect one of them to a file--for example, by using an appropriate
+redirect one of them to a file---for example, by using an appropriate
shell command.
@menu
explicitly permit output to arrive at a specific point, or even to wait
until output arrives from a process.
-@defun accept-process-output &optional process seconds millisec
+@defun accept-process-output &optional process seconds millisec just-this-one
This function allows Emacs to read pending output from processes. The
output is inserted in the associated buffers or given to their filter
functions. If @var{process} is non-@code{nil} then this function does
of a second; on those that do not, you get an error if you specify
nonzero @var{millisec}.
+@c Emacs 21.4 feature
+If @var{process} is a process, and the argument @var{just-this-one} is
+non-nil, only output from that process is handled, suspending output
+from other processes until some output has been received from that
+process or the timeout expires. If @var{just-this-one} is an integer,
+also inhibit running timers. This feature is generally not
+recommended, but may be necessary for specific applications, such as
+speech synthesis.
+
The function @code{accept-process-output} returns non-@code{nil} if it
did get some output, or @code{nil} if the timeout expired before output
arrived.
@end defun
@node Datagrams
-@section Datagrams
+@section Datagrams
@cindex datagrams
A datagram connection communicates with individual packets rather
@end table
The original argument list, modified with the actual connection
-information, is available via the `process-contact' function.
+information, is available via the @code{process-contact} function.
@end defun
@defun set-network-process-option process option value
@var{option} and their corresponding values @var{value}.
The current setting of an option is available via the
-`process-contact' function.
+@code{process-contact} function.
@end defun
@defun network-interface-list
@example
(featurep 'make-network-process '(@var{keyword} @var{value}))
-@end example
+@end example
@noindent
The result of the first form is @code{t} if it works to specify
@example
(featurep 'make-network-process '@var{keyword})
-@end example
+@end example
Here are some of the option @var{keyword}s you can test in
this way.