[Emacs-diffs] Changes to emacs/lispref/processes.texi

[Richard M. Stallman]

Index: emacs/lispref/processes.texi
diff -c emacs/lispref/processes.texi:1.29 emacs/lispref/processes.texi:1.30
*** emacs/lispref/processes.texi:1.29   Mon Jul 14 12:03:25 2003
--- emacs/lispref/processes.texi        Tue Jul 22 11:18:32 2003
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*** 898,926 ****
  redirect one of them to a file--for example, by using an appropriate
  shell command.
  
-   Subprocess output is normally decoded using a coding system before the
- buffer or filter function receives it, much like text read from a file.
- You can use @code{set-process-coding-system} to specify which coding
- system to use (@pxref{Process Information}).  Otherwise, the coding
- system comes from @code{coding-system-for-read}, if that is
- address@hidden; or else from the defaulting mechanism (@pxref{Default
- Coding Systems}).
- 
-   @strong{Warning:} Coding systems such as @code{undecided} which
- determine the coding system from the data do not work entirely reliably
- with asynchronous subprocess output.  This is because Emacs has to
- process asynchronous subprocess output in batches, as it arrives.  Emacs
- must try to detect the proper coding system from one batch at a time,
- and this does not always work.  Therefore, if at all possible, use a
- coding system which determines both the character code conversion and
- the end of line conversion---that is, one like @code{latin-1-unix},
- rather than @code{undecided} or @code{latin-1}.
- 
  @menu
! * Process Buffers::       If no filter, output is put in a buffer.
! * Filter Functions::      Filter functions accept output from the process.
! * Accepting Output::      Explicitly permitting subprocess output.
!                             Waiting for subprocess output.
  @end menu
  
  @node Process Buffers
--- 898,908 ----
  redirect one of them to a file--for example, by using an appropriate
  shell command.
  
  @menu
! * Process Buffers::         If no filter, output is put in a buffer.
! * Filter Functions::        Filter functions accept output from the process.
! * Decoding Ouptut::         Filters can get unibyte or multibyte strings.
! * Accepting Output::        How to wait until process output arrives.
  @end menu
  
  @node Process Buffers
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*** 1161,1166 ****
--- 1143,1197 ----
  @end group
  @end smallexample
  @end ignore
+ 
+ @node Decoding Output
+ @subsection Decoding Process Output
+ 
+   When Emacs writes process output directly into a multibyte buffer,
+ it decodes the output according to the process output coding system.
+ If the coding system is @code{raw-text} or @code{no-conversion}, Emacs
+ converts the unibyte output to multibyte using
+ @code{string-to-multibyte}, inserts the resulting multibyte text.
+ 
+   You can use @code{set-process-coding-system} to specify which coding
+ system to use (@pxref{Process Information}).  Otherwise, the coding
+ system comes from @code{coding-system-for-read}, if that is
+ address@hidden; or else from the defaulting mechanism (@pxref{Default
+ Coding Systems}).
+ 
+   @strong{Warning:} Coding systems such as @code{undecided} which
+ determine the coding system from the data do not work entirely
+ reliably with asynchronous subprocess output.  This is because Emacs
+ has to process asynchronous subprocess output in batches, as it
+ arrives.  Emacs must try to detect the proper coding system from one
+ batch at a time, and this does not always work.  Therefore, if at all
+ possible, specify a coding system that determines both the character
+ code conversion and the end of line conversion---that is, one like
+ @code{latin-1-unix}, rather than @code{undecided} or @code{latin-1}.
+ 
+ @cindex filter multibyte flag, of process
+ @cindex process filter multibyte flag
+   When Emacs calls a process filter function, it provides the process
+ output as a multibyte string or as a unibyte string according to the
+ process's filter multibyte flag.  If the flag is address@hidden, Emacs
+ decodes the output according to the process output coding system to
+ produce a multibyte string, and passes that to the process.  If the
+ flag is @code{nil}, Emacs puts the output into a unibyte string, with
+ no decoding, and passes that.
+ 
+   When you create a process, the filter multibyte flag takes its
+ initial value from @code{default-enable-multibyte-characters}.  If you
+ want to change the flag later on, use
+ @code{set-process-filter-multibyte}.
+ 
+ @defun set-process-filter-multibyte process multibyte
+ This function sets the filter multibyte flag of @var{process}
+ to @var{multibyte}.
+ @end defun
+ 
+ @defun process-filter-multibyte-p process
+ This function returns the filter multibyte flag of @var{process}.
+ @end defun
  
  @node Accepting Output
  @subsection Accepting Output from Processes