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| -rw-r--r-- | doc/lispref/processes.texi | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/doc/lispref/processes.texi b/doc/lispref/processes.texi index 7eb136af5f1..c08b14c72c5 100644 --- a/doc/lispref/processes.texi +++ b/doc/lispref/processes.texi @@ -701,6 +701,19 @@ created with @code{make-pipe-process}, described below. If @var{stderr} is @code{nil}, standard error is mixed with standard output, and both are sent to @var{buffer} or @var{filter}. +@cindex standard error process +If @var{stderr} is a buffer, Emacs will create a pipe process, the +@dfn{standard error process}. This process will have the default +filter (@pxref{Filter Functions}), sentinel (@pxref{Sentinels}), and +coding systems (@pxref{Default Coding Systems}). On the other hand, +it will use @var{query-flag} as its query-on-exit flag (@pxref{Query +Before Exit}). It will be associated with the @var{stderr} buffer +(@pxref{Process Buffers}) and send its output (which is the standard +error of the main process) there. + +If @var{stderr} is a pipe process, Emacs will use it as standard error +process for the new process. + @item :file-handler @var{file-handler} If @var{file-handler} is non-@code{nil}, then look for a file name handler for the current buffer's @code{default-directory}, and invoke @@ -1882,6 +1895,19 @@ like this: (while (accept-process-output process)) @end example +If you have passed a non-@code{nil} @var{stderr} to +@code{make-process}, it will have a standard error process. +@xref{Asynchronous Processes}. In that case, waiting for process +output from the main process doesn't wait for output from the standard +error process. To make sure you have received both all of standard +output and all of standard error from a process, use the following +code: + +@example +(while (accept-process-output process)) +(while (accept-process-output stderr-process)) +@end example + @node Processes and Threads @subsection Processes and Threads @cindex processes, threads |