options

早期freebsd实现

This describes the sequence of Emacs start-up actions, including the meaning
of all the command-line options.  It was written by Joe Wells.

   1. These command line switches are handled, only if they appear before
      all other command line arguments, and only if they appear in this
      order:
  
      `-map'.  Only under VMS.  Instead of "undumping", under VMS the
         contents of a dump file are mapped over a section of memory (very
         quickly initializing lots of variables).  You would not normally
	 use this options explicitly; it is given automatically by the
	 command file that implements the `emacs' command.
  
      `-t'.  The next argument is treated as the name of a terminal to use
         instead of whatever is connected to the stdin, stdout, and stderr
         FILE pointers.
  
      `-display' (synonym: `-d').  The next argument is treated as the
         name of an X Window System server with which to connect.  This
         overrides the DISPLAY environment variable.
  
      `-nw'.  This means don't connect to an X Window server even if the
         DISPLAY environment variable was set or the `-display' switch was
         specified.  Instead, Emacs talks to a regular dumb terminal.
  
      `-batch'.  Run noninteractively.  This disables any full screen
        interaction either with a dumb terminal or with a window system.
        In addition, Emacs will die after processing all command line
        arguments.  The variable `noninteractive' is t.
  
  All of Emacs's internal data structures are initialized between steps 2
  and 5.
  
   2. The `*scratch*' buffer is created and its value of `default-directory'
      is set from the result of calling the `getwd' library routine.
      (getwd does what the `pwd' program does.)
  
   3. If X11 is being used, Emacs determines the name under which it looks
      for X resource values.  (I haven't checked how it does this under
      X10.)
  
      1. If there is a `-rn' command line switch, it is handled now, no
	 matter where it is on the command line.  (Later it will be
	 processed again and ignored.)  The next argument is used as
	 Emacs's resource name.
  
      2. If the `-rn' switch was missing, Emacs looks for the WM_RES_NAME
         environment variable.
  
      3. If neither of the previous two steps succeed, Emacs uses the
         filename with which it was invoked as its resource name.
  
   4. If X11 is being used, these command line switches are handled now,
      no matter where they appear in the command line.  (Under X10, they
      are not handled until step 13.)  WARNING: this can cause strange
      interactions with the processing of the remaining command line
      arguments in step 13.
  
      In addition, under both X11 and X10, X resources (ie. the stuff in
      an `.Xdefaults' file) are handled now.  Command line switches take
      precedence over resources.
  
      After each command line switch are given the equivalent resource
      names in this format: (X10 name / X11 instance name / X11 class name).
  
      `-r'.  Reverse video.  (ReverseVideo/reverseVideo/ReverseVideo)
      `-font' (synonym: `-fn').  Font.  (BodyFont/font/Font)
      `-wn'.  Window name (X11 only).  (/title/Title)
      `-in'.  Icon name (X11 only).  (/iconName/Title)
      `-i'.  Use built-in icon bitmap.  (BitMapIcon//)
  
      `-b'.  Border width (in pixels).
         (BorderWidth/borderWidth/BorderWidth)
  
      `-ib'.  Internal border width (in pixels) (default: 1).
         (/internalBorder/BorderWidth)

      `-xrm RESOURCESTRING'.  Specifies a resource name and value
	 that overrides any other value in the X server for that name.
	 This is useful also for setting parameters that don't have their
	 own specific options.

      `-geometry' (synonym: `-w').  Window shape and size.  `-geometry' is
         X11 only, but its synonym `-w' was available under X10.
         (/geometry/Geometry)
  
      Color options only:
  
      `-fg'.  Foreground color.  (Foreground/foreground/Foreground)
      `-bg'.  Background color.  (Background/background/Background)
      `-bd'.  Border color.  (Border/borderColor/BorderColor)
      `-cr'.  Cursor color.  (Cursor/cursorColor/Foreground)
      `-ms'.  Mouse pointer color.  (Mouse/pointerColor/Foreground)
  
      In addition, under X10, the resource `Keymap' was handled now.
  
   5. If your Emacs isn't dumped, the default Lisp libraries are
      loaded now.
  
   6. Emacs enters a recursive edit.  The first time Emacs does a
      recursive edit, steps 7 through 15 are followed, and then Emacs
      enters its normal editing mode.
  
   7. If the environment variable PWD exists, the value of
      `default-directory' in the `*scratch*' buffer is set to the value of
      PWD.  This often causes problems and confusion when the value of PWD
      doesn't actually contain the pathname of the current directory.
  
   8. Now the `-no-init-file' (synonym: `-q') and `-user' (synonym: `-u')
      command line switches are handled.  They must follow the switches
      mentioned in step 1, and must precede any other command line
      arguments.  Actually, both of these options can be specified;
      whichever is last on the command line wins.
  
   9. The user's `.emacs' file is loaded now, if the `-no-init-file'
      option was not specified.  If the `-user' option was specified,
      that user's init file is loaded instead.  This file is named
      `.emacs' in the user's home directory.  If no such file exists,
      this step has no effect.
  
  10. The system wide `default.el' file is loaded now, if the variable
      `inhibit-default-init' is nil.  The user can set this variable in the
      `.emacs' file to skip this step.
  
  11. If the *scratch* buffer still exists now, the value of
      `initial-major-mode' is called as a function in this buffer.
      Normally, this puts this buffer in Lisp Interaction mode.
  
  12. Now the terminal/window-system setup file is loaded.  The name of
      this file is determined as follows:
  
      1. It starts with the value of `term-file-prefix'.  Normally this is
         `term/', but the user can set it to another value.  If this
         variable is nil, this entire step is skipped.
  
      2. For a window system, the prefix is followed by the name of the
         value of the variable `window-system', followed by `-win'.  For X
         Windows, this means the name is `term/x-win'.
  
      3. For a terminal, the prefix is followed by the value of the
         environment variable TERM, for example, `term/vt200'.  If Emacs
         cannot find such a file to load, it retries by stripping off
         suffixes that begin with a hyphen.  For example, if TERM is
         `vt200-40', first Emacs will try `term/vt200-40', and if that
         fails it will try `term/vt200'.
  
  13. The rest of the command line arguments are handled at this point, in
      the order they appear:
  
      `-funcall' (synonyms: `-f', `-e').  The next argument is treated as
         the name of a function, which is called with no arguments.
  
      `-load' (synonym: `-l').  The next argument is treated as the name
         of a file to load.  NOTE: the value of the variable `load-path'
         will be restored after this file is done loading.  Thus, trying
         to change `load-path' in such a file will fail!!
  
      `-kill'.  When this argument is handled, Emacs kills itself.
  
      `+DDD', where D is a digit.  DDD is used as a line number to go to.
         When the next ordinary file argument on the command line is
         handled, Emacs positions point in that file on line DDD.
  
      An ordinary filename.  Emacs edits this file using the function
         `find-file'.  If the filename is not an absolute filename, it is
         expanded relative to the value that default-directory in the
         `*scratch*' buffer had at the beginning of step 11.  The buffer
         visiting this file becomes the current buffer.
  
      `-insert' (synonym: `-i').  The next argument is treated as the name
         of a file.  This file is inserted in the current buffer.
         Initially, this is the `*scratch*' buffer.  Otherwise it is the
         buffer visiting the file most recently specified on the command
         line.
  
      Other command line switches may have been created by modifying the
      value of the variable `command-switch-alist'.  If X Windows is being
      used, all X-specific switches mentioned above in steps 3 and 4 will
      be processed.  Under X11, they will have already been handled, and
      will be ignored now.  Under X10, they are being handled for the
      first time.
  
  14. The values of the variables `term-setup-hook' and `window-setup-hook'
      are called as functions with no arguments, in the order listed.
  
  15. If the user did not specify any of the command line options handled
      in step 13, and the variable `inhibit-startup-message' is still nil,
      the familiar Emacs startup message is displayed.