Doc and manual fixes related to processes

* doc/lispref/processes.texi (Processes, Subprocess Creation, Shell Arguments):
(Synchronous Processes): Copyedits.
(Subprocess Creation): Discourage modifying exec-path directly.
(Synchronous Processes): Update some example output.
(Process Information): Fix typo.
(Bindat Spec): Use Texinfo-recommended form of quote+punctuation.

* lisp/simple.el (process-file-side-effects): Doc fix.

doc/lispref/ChangeLog

+2012-04-15  Glenn Morris  <rgm@gnu.org>
+
+	* processes.texi (Processes, Subprocess Creation, Shell Arguments):
+	(Synchronous Processes): Copyedits.
+	(Subprocess Creation): Discourage modifying exec-path directly.
+	(Synchronous Processes): Update some example output.
+	(Process Information): Fix typo.
+	(Bindat Spec): Use Texinfo-recommended form of quote+punctuation.
+
 2012-04-14  Glenn Morris  <rgm@gnu.org>
 
 	* anti.texi (Antinews): Copyedits.  Don't @dfn anything here.

doc/lispref/processes.texi

@@ -23,7 +23,7 @@ subprocess, the Lisp program waits for the subprocess to terminate
 before continuing execution.  When you create an asynchronous
 subprocess, it can run in parallel with the Lisp program.  This kind of
 subprocess is represented within Emacs by a Lisp object which is also
-called a ``process.''  Lisp programs can use this object to communicate
+called a ``process''.  Lisp programs can use this object to communicate
 with the subprocess or to control it.  For example, you can send
 signals, obtain status information, receive output from the process, or
 send input to it.
@@ -70,7 +70,9 @@ a program.  One of them, @code{start-process}, creates an asynchronous
 process and returns a process object (@pxref{Asynchronous Processes}).
 The other two, @code{call-process} and @code{call-process-region},
 create a synchronous process and do not return a process object
-(@pxref{Synchronous Processes}).
+(@pxref{Synchronous Processes}).  There are various higher-level
+functions that make use of these primitives to run particular types of
+process.
 
   Synchronous and asynchronous processes are explained in the following
 sections.  Since the three functions are all called in a similar
@@ -104,16 +106,19 @@ system-dependent.
 
   @strong{Please note:} The argument @var{program} contains only the
 name of the program; it may not contain any command-line arguments.  You
-must use @var{args} to provide those.
+must use a separate argument, @var{args}, to provide those, as
+described below.
 
   Each of the subprocess-creating functions has a @var{buffer-or-name}
-argument which specifies where the standard output from the program will
+argument that specifies where the standard output from the program will
 go.  It should be a buffer or a buffer name; if it is a buffer name,
 that will create the buffer if it does not already exist.  It can also
 be @code{nil}, which says to discard the output unless a filter function
 handles it.  (@xref{Filter Functions}, and @ref{Read and Print}.)
 Normally, you should avoid having multiple processes send output to the
 same buffer because their output would be intermixed randomly.
+For synchronous processes, you can send the output to a file instead
+of a buffer.
 
 @cindex program arguments
   All three of the subprocess-creating functions have a @code{&rest}
@@ -122,18 +127,16 @@ supplied to @var{program} as separate command line arguments.  Wildcard
 characters and other shell constructs have no special meanings in these
 strings, since the strings are passed directly to the specified program.
 
-  The subprocess gets its current directory from the value of
-@code{default-directory} (@pxref{File Name Expansion}).
-
 @cindex environment variables, subprocesses
   The subprocess inherits its environment from Emacs, but you can
 specify overrides for it with @code{process-environment}.  @xref{System
-Environment}.
+Environment}.  The subprocess gets its current directory from the
+value of @code{default-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
+contains programs that come with GNU Emacs and are intended for Emacs
 to invoke.  The program @code{movemail} is an example of such a program;
 Rmail uses it to fetch new mail from an inbox.
 @end defvar
@@ -148,6 +151,11 @@ directory (which is the value of @code{default-directory}).
 The value of @code{exec-path} is used by @code{call-process} and
 @code{start-process} when the @var{program} argument is not an absolute
 file name.
+
+Generally, you should not modify @code{exec-path} directly.  Instead,
+ensure that your @env{PATH} environment variable is set appropriately
+before starting Emacs.  Trying to modify @code{exec-path}
+independently of @env{PATH} can lead to confusing results.
 @end defopt
 
 @node Shell Arguments
@@ -163,7 +171,7 @@ occur in the file name, they will confuse the shell.  To handle these
 characters, use the function @code{shell-quote-argument}:
 
 @defun shell-quote-argument argument
-This function returns a string which represents, in shell syntax,
+This function returns a string that represents, in shell syntax,
 an argument whose actual contents are @var{argument}.  It should
 work reliably to concatenate the return value into a shell command
 and then pass it to a shell for execution.
@@ -201,10 +209,10 @@ a shell command:
   The following two functions are useful for combining a list of
 individual command-line argument strings into a single string, and
 taking a string apart into a list of individual command-line
-arguments.  These functions are mainly intended to be used for
+arguments.  These functions are mainly intended for
 converting user input in the minibuffer, a Lisp string, into a list of
 string arguments to be passed to @code{call-process} or
-@code{start-process}, or for the converting such lists of arguments in
+@code{start-process}, or for converting such lists of arguments into
 a single Lisp string to be presented in the minibuffer or echo area.
 
 @defun split-string-and-unquote string &optional separators
@@ -345,7 +353,7 @@ In the examples below, the buffer @samp{foo} is current.
      @result{} 0
 
 ---------- Buffer: foo ----------
-/usr/user/lewis/manual
+/home/lewis/manual
 ---------- Buffer: foo ----------
 @end group
 
@@ -354,18 +362,18 @@ In the examples below, the buffer @samp{foo} is current.
      @result{} 0
 
 ---------- Buffer: bar ----------
-lewis:5LTsHm66CSWKg:398:21:Bil Lewis:/user/lewis:/bin/csh
+lewis:x:1001:1001:Bil Lewis,,,,:/home/lewis:/bin/bash
 
 ---------- Buffer: bar ----------
 @end group
 @end smallexample
 
-Here is a good example of the use of @code{call-process}, which used to
-be found in the definition of @code{insert-directory}:
+Here is an example of the use of @code{call-process}, as used to
+be found in the definition of the @code{insert-directory} function:
 
 @smallexample
 @group
-(call-process insert-directory-program nil t nil @var{switches}
+(call-process insert-directory-program nil t nil switches
               (if full-directory-p
                   (concat (file-name-as-directory file) ".")
                 file))
@@ -375,9 +383,9 @@ be found in the definition of @code{insert-directory}:
 
 @defun process-file program &optional infile buffer display &rest args
 This function processes files synchronously in a separate process.  It
-is similar to @code{call-process} but may invoke a file handler based
-on the value of the variable @code{default-directory}.  The current
-working directory of the subprocess is @code{default-directory}.
+is similar to @code{call-process}, but may invoke a file handler based
+on the value of the variable @code{default-directory}, which specifies
+the current working directory of the subprocess.
 
 The arguments are handled in almost the same way as for
 @code{call-process}, with the following differences:
@@ -390,15 +398,15 @@ file handlers might not support separating standard output and error
 output by way of the @var{buffer} argument.
 
 If a file handler is invoked, it determines the program to run based
-on the first argument @var{program}.  For instance, consider that a
+on the first argument @var{program}.  For instance, suppose that a
 handler for remote files is invoked.  Then the path that is used for
-searching the program might be different than @code{exec-path}.
+searching for the program might be different from @code{exec-path}.
 
 The second argument @var{infile} may invoke a file handler.  The file
 handler could be different from the handler chosen for the
 @code{process-file} function itself.  (For example,
-@code{default-directory} could be on a remote host, whereas
-@var{infile} is on another remote host.  Or @code{default-directory}
+@code{default-directory} could be on one remote host, and
+@var{infile} on a different remote host.  Or @code{default-directory}
 could be non-special, whereas @var{infile} is on a remote host.)
 
 If @var{buffer} is a list of the form @code{(@var{real-destination}
@@ -415,16 +423,16 @@ file names.
 @end defun
 
 @defvar process-file-side-effects
-This variable indicates, whether a call of @code{process-file} changes
+This variable indicates whether a call of @code{process-file} changes
 remote files.
 
-Per default, this variable is always set to @code{t}, meaning that a
+By default, this variable is always set to @code{t}, meaning that a
 call of @code{process-file} could potentially change any file on a
 remote host.  When set to @code{nil}, a file handler could optimize
-its behavior with respect to remote file attributes caching.
+its behavior with respect to remote file attribute caching.
 
-This variable should never be changed by @code{setq}.  Instead of, it
-shall be set only by let-binding.
+You should only ever change this variable with a let-binding; never
+with @code{setq}.
 @end defvar
 
 @defun call-process-region start end program &optional delete destination display &rest args
@@ -440,7 +448,7 @@ as it comes in.  For details, see the description of
 @code{call-process}, above.  If @var{destination} is the integer 0,
 @code{call-process-region} discards the output and returns @code{nil}
 immediately, without waiting for the subprocess to finish (this only
-works if asynchronous subprocesses are supported).
+works if asynchronous subprocesses are supported; i.e. not on MS-DOS).
 
 The remaining arguments, @var{args}, are strings that specify command
 line arguments for the program.
@@ -474,18 +482,18 @@ inputinput@point{}
 @end group
 @end smallexample
 
-  The @code{shell-command-on-region} command uses
-@code{call-process-region} like this:
+  For example, the @code{shell-command-on-region} command uses
+@code{call-process-region} in a manner similar to this:
 
 @smallexample
 @group
 (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}.}
- nil                  ; @r{No redisplay during output.}
- "-c" command)        ; @r{Arguments for the shell.}
+ shell-file-name      ; @r{name of program}
+ nil                  ; @r{do not delete region}
+ buffer               ; @r{send output to @code{buffer}}
+ nil                  ; @r{no redisplay during output}
+ "-c" command)        ; @r{arguments for the shell}
 @end group
 @end smallexample
 @end defun
@@ -508,6 +516,9 @@ This function executes @var{command} (a string) as a shell command,
 then returns the command's output as a string.
 @end defun
 
+@c There is also shell-command-on-region, but that is more of a user
+@c command, not something to use in programs.
+
 @defun process-lines program &rest args
 This function runs @var{program}, waits for it to finish, and returns
 its output as a list of strings.  Each string in the list holds a
@@ -864,7 +875,7 @@ closed the connection, or Emacs did @code{delete-process}.
 @end defun
 
 @defun process-live-p process
-This function returns nin-@code{nil} if @var{process} is alive.  A
+This function returns non-@code{nil} if @var{process} is alive.  A
 process is considered alive if its status is @code{run}, @code{open},
 @code{listen}, @code{connect} or @code{stop}.
 @end defun
@@ -2662,7 +2673,7 @@ specification}, a special nested list describing named and typed
 @dfn{fields}.  This specification controls length of each field to be
 processed, and how to pack or unpack it.  We normally keep bindat specs
 in variables whose names end in @samp{-bindat-spec}; that kind of name
-is automatically recognized as ``risky.''
+is automatically recognized as ``risky''.
 
 @cindex endianness
 @cindex big endian
@@ -2672,7 +2683,7 @@ is automatically recognized as ``risky.''
 that the field represents and, in the case of multibyte fields, how
 the bytes are ordered within the field.  The two possible orderings
 are ``big endian'' (also known as ``network byte ordering'') and
-``little endian.''  For instance, the number @code{#x23cd} (decimal
+``little endian''.  For instance, the number @code{#x23cd} (decimal
 9165) in big endian would be the two bytes @code{#x23} @code{#xcd};
 and in little endian, @code{#xcd} @code{#x23}.  Here are the possible
 type values:

lisp/ChangeLog

+2012-04-15  Glenn Morris  <rgm@gnu.org>
+
+	* simple.el (process-file-side-effects): Doc fix.
+
 2012-04-14  Glenn Morris  <rgm@gnu.org>
 
 	* international/mule-cmds.el (set-language-environment): Doc fix.

lisp/simple.el

 ;;; simple.el --- basic editing commands for Emacs
 
-;; Copyright (C) 1985-1987, 1993-2012  Free Software Foundation, Inc.
+;; Copyright (C) 1985-1987, 1993-2012 Free Software Foundation, Inc.
 
 ;; Maintainer: FSF
 ;; Keywords: internal
@@ -2677,13 +2677,13 @@ value passed."
 (defvar process-file-side-effects t
   "Whether a call of `process-file' changes remote files.
 
-Per default, this variable is always set to `t', meaning that a
+By default, this variable is always set to `t', meaning that a
 call of `process-file' could potentially change any file on a
 remote host.  When set to `nil', a file handler could optimize
-its behavior with respect to remote file attributes caching.
+its behavior with respect to remote file attribute caching.
 
-This variable should never be changed by `setq'.  Instead of, it
-shall be set only by let-binding.")
+You should only ever change this variable with a let-binding;
+never with `setq'.")
 
 (defun start-file-process (name buffer program &rest program-args)
   "Start a program in a subprocess.  Return the process object for it.