X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/8241495da57ca0efed1b2e86ff693b5614e0aebd..8325c01e4ba922ee7d6bb60651c25db3b0adbbce:/lispref/os.texi diff --git a/lispref/os.texi b/lispref/os.texi index 06c297ab88..d6a58910f4 100644 --- a/lispref/os.texi +++ b/lispref/os.texi @@ -1,9 +1,10 @@ @c -*-texinfo-*- @c This is part of the GNU Emacs Lisp Reference Manual. -@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998 Free Software Foundation, Inc. +@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999 +@c Free Software Foundation, Inc. @c See the file elisp.texi for copying conditions. @setfilename ../info/os -@node System Interface, Tips, Calendar, Top +@node System Interface, Antinews, Calendar, Top @chapter Operating System Interface This chapter is about starting and getting out of Emacs, access to @@ -26,7 +27,7 @@ pertaining to the terminal and the screen. * Terminal Input:: Recording terminal input for debugging. * Terminal Output:: Recording terminal output for debugging. * Sound Output:: Playing sounds on the computer's speaker. -* Special Keysyms:: Defining system-specific key symbols for X windows. +* Special Keysyms:: Defining system-specific key symbols for X. * Flow Control:: How to turn output flow control on or off. * Batch Mode:: Running Emacs without terminal interaction. @end menu @@ -56,8 +57,11 @@ it is started up is as follows: @enumerate @item -It adds subdirectories to @code{load-path}, by running the file -named @file{subdirs.el} in each directory that is listed. +It adds subdirectories to @code{load-path}, by running the file named +@file{subdirs.el} in each directory in the list. Normally this file +adds the directory's subdirectories to the list, and these will be +scanned in their turn. The files @file{subdirs.el} are normally +generated automatically by Emacs installation. @item It sets the language environment and the terminal coding system, @@ -85,9 +89,10 @@ It loads the library @file{site-start}, unless the option @cindex @file{site-start.el} @item -It loads the file @file{~/.emacs}, unless @samp{-q} or @samp{-batch} was -specified on the command line. The @samp{-u} option can specify another -user whose home directory should be used instead of @file{~}. +It loads your init file (usually @file{~/.emacs}), unless @samp{-q}, +@samp{-no-init-file}, or @samp{-batch} was specified on the command line. +The @samp{-u} option can specify another user whose home directory +should be used instead of @file{~}. @item It loads the library @file{default}, unless @code{inhibit-default-init} @@ -116,7 +121,7 @@ that with @code{inhibit-startup-echo-area-message}. It processes the action arguments from the command line. @item -It runs @code{term-setup-hook}. +It runs @code{emacs-startup-hook} and then @code{term-setup-hook}. @item It calls @code{frame-notice-user-settings}, which modifies the @@ -147,36 +152,45 @@ the information they are supposed to see. @defopt inhibit-startup-echo-area-message This variable controls the display of the startup echo area message. You can suppress the startup echo area message by adding text with this -form to your @file{.emacs} file: +form to your init file: @example (setq inhibit-startup-echo-area-message "@var{your-login-name}") @end example -Emacs explicitly checks for an expression as shown above in your -@file{.emacs} file; your login name must appear in the expression as a -Lisp string constant. Other methods of setting +Emacs explicitly checks for an expression as shown above in your init +file; your login name must appear in the expression as a Lisp string +constant. Other methods of setting @code{inhibit-startup-echo-area-message} to the same value do not inhibit the startup message. This way, you can easily inhibit the message for yourself if you wish, -but thoughtless copying of your @file{.emacs} file will not inhibit the -message for someone else. +but thoughtless copying of your init file will not inhibit the message +for someone else. @end defopt @node Init File -@subsection The Init File: @file{.emacs} +@subsection The Init File, @file{.emacs} @cindex init file @cindex @file{.emacs} - When you start Emacs, it normally attempts to load the file -@file{.emacs} from your home directory. This file is called your -@dfn{init file}. If it exists, it must contain Lisp code. The -command-line switches @samp{-q} and @samp{-u} affect the use of the init -file; @samp{-q} says not to load an init file, and @samp{-u} says to -load a specified user's init file instead of yours. @xref{Entering -Emacs,,, emacs, The GNU Emacs Manual}. + When you start Emacs, it normally attempts to load your @dfn{init +file}, a file in your home directory. Its normal name is @file{.emacs}, +but you can alternatively call it @file{.emacs.el}, which enables you to +byte-compile it (@pxref{Byte Compilation}); then the actual file loaded +will be @file{.emacs.elc}. + + The command-line switches @samp{-q} and @samp{-u} control whether and +where to find the init file; @samp{-q} says not to load an init file, +and @samp{-u @var{user}} says to load @var{user}'s init file instead of +yours. @xref{Entering Emacs,,, emacs, The GNU Emacs Manual}. If +neither option is specified, Emacs uses the @code{LOGNAME} environment +variable, or the @code{USER} (most systems) or @code{USERNAME} (MS +systems) variable, to find your home directory and thus your init file; +this way, even if you have su'd, Emacs still loads your own init file. +If those environment variables are absent, though, Emacs uses your +user-id to find your home directory. @cindex default init file A site may have a @dfn{default init file}, which is the library named @@ -200,10 +214,6 @@ way you can change it with real effect is to do so before dumping Emacs. @end defvar - If there is a great deal of code in your @file{.emacs} file, you -can make it load faster by renaming it to @file{.emacs.el} -and then byte-compiling it (@pxref{Byte Compilation}). - @xref{Init File Examples,,, emacs, The GNU Emacs Manual}, for examples of how to make various commonly desired customizations in your @file{.emacs} file. @@ -224,7 +234,21 @@ This normal hook is run, once, just before loading all the init files @defvar after-init-hook This normal hook is run, once, just after loading all the init files (the user's init file, @file{default.el}, and/or @file{site-start.el}), -before the terminal-specific initialization. +before loading the terminal-specific library and processing the +command-line arguments. +@end defvar + +@defvar emacs-startup-hook +@tindex emacs-startup-hook +This normal hook is run, once, just after handling the command line +arguments, just before @code{term-setup-hook}. +@end defvar + +@defvar user-init-file +@tindex user-init-file +This variable holds the file name of the user's init file. If the +actual init file loaded is a compiled file, such as @file{.emacs.elc}, +the value refers to the corresponding source file. @end defvar @node Terminal-Specific @@ -253,7 +277,7 @@ the @file{term/aaa} library. If necessary, the library can evaluate @code{(getenv "TERM")} to find the full name of the terminal type.@refill - Your @file{.emacs} file can prevent the loading of the + Your init file can prevent the loading of the terminal-specific library by setting the variable @code{term-file-prefix} to @code{nil}. This feature is useful when experimenting with your own peculiar customizations. @@ -262,7 +286,7 @@ experimenting with your own peculiar customizations. terminal-specific library by setting the variable @code{term-setup-hook}. This is a normal hook which Emacs runs using @code{run-hooks} at the end of Emacs initialization, after loading both -your @file{.emacs} file and any terminal-specific libraries. You can +your init file and any terminal-specific libraries. You can use this variable to define initializations for terminals that do not have their own libraries. @xref{Hooks}. @@ -277,9 +301,9 @@ a terminal-specific initialization file as follows: @noindent You may set the @code{term-file-prefix} variable to @code{nil} in your -@file{.emacs} file if you do not wish to load the +init file if you do not wish to load the terminal-initialization file. To do this, put the following in -your @file{.emacs} file: @code{(setq term-file-prefix nil)}. +your init file: @code{(setq term-file-prefix nil)}. On MS-DOS, if the environment variable @code{TERM} is not set, Emacs uses @samp{internal} as the terminal type. @@ -287,7 +311,7 @@ uses @samp{internal} as the terminal type. @defvar term-setup-hook This variable is a normal hook that Emacs runs after loading your -@file{.emacs} file, the default initialization file (if any) and the +init file, the default initialization file (if any) and the terminal-specific Lisp file. You can use @code{term-setup-hook} to override the definitions made by a @@ -327,7 +351,7 @@ kill the Emacs until you are about to log out.) @defun command-line This function parses the command line that Emacs was called with, -processes it, loads the user's @file{.emacs} file and displays the +processes it, loads the user's init file and displays the startup messages. @end defun @@ -481,7 +505,7 @@ subprocess of Emacs. Then you would exit the shell to return to Emacs. may not have a parent that can resume it again, and in any case you can give input to some other job such as a shell merely by moving to a different window. Therefore, suspending is not allowed when Emacs is using -a window system (X Windows or MS Windows). +a window system (X or MS Windows). @defun suspend-emacs string This function stops Emacs and returns control to the superior process. @@ -663,7 +687,7 @@ done when Emacs starts up, the value actually used is the one saved when Emacs was dumped. @xref{Building Emacs}.) @end defvar -@defun getenv var +@deffn Command getenv var @cindex environment variable access This function returns the value of the environment variable @var{var}, as a string. Within Emacs, the environment variable values are kept in @@ -686,7 +710,7 @@ SHELL=/bin/csh HOME=/user/lewis @end group @end example -@end defun +@end deffn @c Emacs 19 feature @deffn Command setenv variable value @@ -714,6 +738,10 @@ process-environment "HOME=/user/lewis") @end group @end smallexample + +If @code{process-environment} contains ``duplicate'' elements that +specify the same environment variable, the first of these elements +specifies the variable, and the other ``duplicates'' are ignored. @end defvar @defvar path-separator @@ -723,6 +751,20 @@ value is @code{":"} for Unix and GNU systems, and @code{";"} for MS-DOS and MS-Windows. @end defvar +@defun parse-colon-path path +@tindex parse-colon-path +This function takes a search path string such as would be the value of +the @code{PATH} environment variable, and splits it at the separators, +returning a list of directory names. @code{nil} in this list stands for +``use the current directory.'' Although the function's name says +``colon,'' it actually uses the value of @code{path-separator}. + +@example +(parse-colon-path ":/foo:/bar") + @result{} (nil "/foo/" "/bar/") +@end example +@end defun + @defvar invocation-name This variable holds the program name under which Emacs was invoked. The value is a string, and does not include a directory name. @@ -773,7 +815,6 @@ This function returns the process @sc{id} of the Emacs process. @end defun @defvar tty-erase-char -@tindex tty-erase-char This variable holds the erase character that was selected in the system's terminal driver, before Emacs was started. @end defvar @@ -811,7 +852,7 @@ files or user profile. This holds the nominal email address of the user who is using Emacs. Emacs normally sets this variable to a default value after reading your init files, but not if you have already set it. So you can set the -variable to some other value in your @file{~/.emacs} file if you do not +variable to some other value in your init file if you do not want to use the default value. @end defvar @@ -920,9 +961,9 @@ This function returns the system's time value as a list of three integers: @code{(@var{high} @var{low} @var{microsec})}. The integers @var{high} and @var{low} combine to give the number of seconds since 0:00 January 1, 1970 (local time), which is -@ifinfo +@ifnottex @var{high} * 2**16 + @var{low}. -@end ifinfo +@end ifnottex @tex $high*2^{16}+low$. @end tex @@ -958,6 +999,18 @@ integers. Thus, you can use times obtained from @code{current-time} (see above) and from @code{file-attributes} (@pxref{File Attributes}). @end defun +@defun float-time &optional time-value +This function returns the current time as a floating-point number of +seconds since the epoch. The argument @var{time-value}, if given, +specifies a time to convert instead of the current time. The argument +should have the same form as for @code{current-time-string} (see +above), and it also accepts the output of @code{current-time} and +@code{file-attributes}. + +@emph{Warning}: Since the result is floating point, it may not be +exact. Do not use this function if precise time stamps are required. +@end defun + @node Time Conversion @section Time Conversion @@ -979,11 +1032,12 @@ the number of years since the year 1 B.C., and do not skip zero as traditional Gregorian years do; for example, the year number @minus{}37 represents the Gregorian year 38 B.C@. -@defun format-time-string format-string time -This function converts @var{time} to a string according to -@var{format-string}. The argument @var{format-string} may contain -@samp{%}-sequences which say to substitute parts of the time. Here is a -table of what the @samp{%}-sequences mean: +@defun format-time-string format-string &optional time universal +This function converts @var{time} (or the current time, if @var{time} is +omitted) to a string according to @var{format-string}. The argument +@var{format-string} may contain @samp{%}-sequences which say to +substitute parts of the time. Here is a table of what the +@samp{%}-sequences mean: @table @samp @item %a @@ -1067,6 +1121,29 @@ For example, @samp{%S} specifies the number of seconds since the minute; @samp{%03S} means to pad this with zeros to 3 positions, @samp{%_3S} to pad with spaces to 3 positions. Plain @samp{%3S} pads with zeros, because that is how @samp{%S} normally pads to two positions. + +The characters @samp{E} and @samp{O} act as modifiers when used between +@samp{%} and one of the letters in the table above. @samp{E} specifies +using the current locale's ``alternative'' version of the date and time. +In a Japanese locale, for example, @code{%Ex} might yield a date format +based on the Japanese Emperors' reigns. @samp{E} is allowed in +@samp{%Ec}, @samp{%EC}, @samp{%Ex}, @samp{%EX}, @samp{%Ey}, and +@samp{%EY}. + +@samp{O} means to use the current locale's ``alternative'' +representation of numbers, instead of the ordinary decimal digits. This +is allowed with most letters, all the ones that output numbers. + +If @var{universal} is non-@code{nil}, that means to describe the time as +Universal Time; @code{nil} means describe it using what Emacs believes +is the local time zone (see @code{current-time-zone}). + +This function uses the C library function @code{strftime} to do most of +the work. In order to communicate with that function, it first encodes +its argument using the coding system specified by +@code{locale-coding-system} (@pxref{Locales}); after @code{strftime} +returns the resulting string, @code{format-time-string} decodes the +string using that same coding system. @end defun @defun decode-time time @@ -1106,14 +1183,14 @@ Greenwich. @var{dow} and @var{zone}. @end defun -@defun encode-time seconds minutes hour day month year &optional @dots{}zone +@defun encode-time seconds minutes hour day month year &optional zone This function is the inverse of @code{decode-time}. It converts seven items of calendrical data into a time value. For the meanings of the arguments, see the table above under @code{decode-time}. Year numbers less than 100 are not treated specially. If you want them -to stand for years above 1900, you must alter them yourself before you -call @code{encode-time}. +to stand for years above 1900, or years above 2000, you must alter them +yourself before you call @code{encode-time}. The optional argument @var{zone} defaults to the current time zone and its daylight savings time rules. If specified, it can be either a list @@ -1558,9 +1635,12 @@ they were used as parts of key sequences. Thus, you always get the last 100 input events, not counting events generated by keyboard macros. (These are excluded because they are less interesting for debugging; it should be enough to see the events that invoked the macros.) + +A call to @code{clear-this-command-keys} (@pxref{Command Loop Info}) +causes this function to return an empty vector immediately afterward. @end defun -@deffn Command open-dribble-file filename +@deffn Command open-dribble-file filename @cindex dribble file This function opens a @dfn{dribble file} named @var{filename}. When a dribble file is open, each input event from the keyboard or mouse (but @@ -1684,10 +1764,19 @@ This specifies the file containing the sound to play. If the file name is not absolute, it is expanded against the directory @code{data-directory}. +@item :data @var{data} +This specifies the sound to play without need to refer to a file. The +value, @var{data}, should be a string containing the same bytes as a +sound file. We recommend using a unibyte string. + @item :volume @var{volume} This specifies how loud to play the sound. It should be a number in the range of 0 to 1. The default is to use whatever volume has been specified before. + +@item :device @var{device} +This specifies the system device on which to play the sound, as a +string. The default device is system-dependent. @end table Before actually playing the sound, @code{play-sound} @@ -1695,6 +1784,12 @@ calls the functions in the list @code{play-sound-functions}. Each function is called with one argument, @var{sound}. @end defun +@defun play-sound-file file &optional volume device +@tindex play-sound-file +This function is an alternative interface to playing a sound @var{file} +specifying an optional @var{volume} and @var{device}. +@end defun + @tindex play-sound-functions @defvar play-sound-functions A list of functions to be called before playing a sound. Each function @@ -1712,9 +1807,9 @@ This variable's value should be an alist with one element for each system-specific keysym. Each element has the form @code{(@var{code} . @var{symbol})}, where @var{code} is the numeric keysym code (not including the ``vendor specific'' bit, -@ifinfo +@ifnottex -2**28), -@end ifinfo +@end ifnottex @tex $-2^{28}$), @end tex @@ -1722,9 +1817,9 @@ and @var{symbol} is the name for the function key. For example @code{(168 . mute-acute)} defines a system-specific key (used by HP X servers) whose numeric code is -@ifinfo +@ifnottex -2**28 -@end ifinfo +@end ifnottex @tex $-2^{28}$ @end tex @@ -1788,7 +1883,7 @@ for them using @code{keyboard-translate-table} (@pxref{Translating Input}). @end deffn You can use the function @code{enable-flow-control-on} in your -@file{.emacs} file to enable flow control automatically on certain +init file to enable flow control automatically on certain terminal types. @defun enable-flow-control-on &rest termtypes @@ -1841,7 +1936,9 @@ calls @var{function} with no arguments. Any Lisp program output that would normally go to the echo area, either using @code{message}, or using @code{prin1}, etc., with @code{t} as the stream, goes instead to Emacs's standard error descriptor when -in batch mode. Thus, Emacs behaves much like a noninteractive +in batch mode. Similarly, input that would normally come from the +minibuffer is read from the standard input descriptor. +Thus, Emacs behaves much like a noninteractive application program. (The echo area output that Emacs itself normally generates, such as command echoing, is suppressed entirely.)