@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2004
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2002, 2003,
+@c 2004, 2005 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/os
@node System Interface, Antinews, Display, Top
* System Environment:: Distinguish the name and kind of system.
* User Identification:: Finding the name and user id of the user.
* Time of Day:: Getting the current time.
-* Time Conversion:: Converting a time from numeric form to a string, or
- to calendrical data (or vice versa).
+* Time Conversion:: Converting a time from numeric form
+ to calendrical data, and vice versa).
+* Time Parsing:: Converting a time from numeric form to text
+ and vice versa.
* Processor Run Time:: Getting the run time used by Emacs.
* Time Calculations:: Adding, subtracting, comparing times, etc.
* Timers:: Setting a timer to call a function at a certain time.
@cindex @file{site-start.el}
@item
-It loads your init file (usually @file{~/.emacs}), unless @samp{-q}
-(or @samp{--no-init-file}), @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 the option
+@samp{-q} (or @samp{--no-init-file}), @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{~}.
@item
It loads the library @file{default} (if any), unless
@item
It displays the initial echo area message, unless you have suppressed
-that with @code{inhibit-startup-echo-area-message} or @samp{-Q}.
+that with @code{inhibit-startup-echo-area-message}.
@item
It processes the action arguments from the command line.
@item
It displays copyleft, nonwarranty, and basic use information, provided
the value of @code{inhibit-startup-message} is @code{nil}, you didn't
-specify @samp{--no-splash} or @samp{-Q}, and the buffer is still empty.
+specify @samp{--no-splash} or @samp{-Q}.
@end enumerate
@defopt inhibit-startup-message
system, the user's @acronym{UID}, and so on.
@defvar system-configuration
-This variable holds the GNU configuration name for the hardware/software
-configuration of your system, as a string. The convenient way to test
-parts of this string is with @code{string-match}.
+This variable holds the standard GNU configuration name for the
+hardware/software configuration of your system, as a string. The
+convenient way to test parts of this string is with
+@code{string-match}.
@end defvar
@defvar system-type
@section Time Conversion
These functions convert time values (lists of two or three integers)
-to strings or to calendrical information. There is also a function to
-convert calendrical information to a time value. You can get time
-values from the functions @code{current-time} (@pxref{Time of Day}) and
+to calendrical information and vice versa. You can get time values
+from the functions @code{current-time} (@pxref{Time of Day}) and
@code{file-attributes} (@pxref{Definition of file-attributes}).
-Many operating systems are limited to time values that contain 32 bits
+ Many operating systems are limited to time values that contain 32 bits
of information; these systems typically handle only the times from
1901-12-13 20:45:52 UTC through 2038-01-19 03:14:07 UTC. However, some
operating systems have larger time values, and can represent times far
in the past or future.
-Time conversion functions always use the Gregorian calendar, even for
-dates before the Gregorian calendar was introduced. Year numbers count
-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@.
+ Time conversion functions always use the Gregorian calendar, even
+for dates before the Gregorian calendar was introduced. Year numbers
+count 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 decode-time &optional time
+This function converts a time value into calendrical information. If
+you don't specify @var{time}, it decodes the current time. The return
+value is a list of nine elements, as follows:
+
+@example
+(@var{seconds} @var{minutes} @var{hour} @var{day} @var{month} @var{year} @var{dow} @var{dst} @var{zone})
+@end example
+
+Here is what the elements mean:
+
+@table @var
+@item seconds
+The number of seconds past the minute, as an integer between 0 and 59.
+On some operating systems, this is 60 for leap seconds.
+@item minutes
+The number of minutes past the hour, as an integer between 0 and 59.
+@item hour
+The hour of the day, as an integer between 0 and 23.
+@item day
+The day of the month, as an integer between 1 and 31.
+@item month
+The month of the year, as an integer between 1 and 12.
+@item year
+The year, an integer typically greater than 1900.
+@item dow
+The day of week, as an integer between 0 and 6, where 0 stands for
+Sunday.
+@item dst
+@code{t} if daylight savings time is effect, otherwise @code{nil}.
+@item zone
+An integer indicating the time zone, as the number of seconds east of
+Greenwich.
+@end table
+
+@strong{Common Lisp Note:} Common Lisp has different meanings for
+@var{dow} and @var{zone}.
+@end defun
+
+@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, 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
+(as you would get from @code{current-time-zone}), a string as in the
+@code{TZ} environment variable, @code{t} for Universal Time, or an
+integer (as you would get from @code{decode-time}). The specified
+zone is used without any further alteration for daylight savings time.
+
+If you pass more than seven arguments to @code{encode-time}, the first
+six are used as @var{seconds} through @var{year}, the last argument is
+used as @var{zone}, and the arguments in between are ignored. This
+feature makes it possible to use the elements of a list returned by
+@code{decode-time} as the arguments to @code{encode-time}, like this:
+
+@example
+(apply 'encode-time (decode-time @dots{}))
+@end example
+
+You can perform simple date arithmetic by using out-of-range values for
+the @var{seconds}, @var{minutes}, @var{hour}, @var{day}, and @var{month}
+arguments; for example, day 0 means the day preceding the given month.
+
+The operating system puts limits on the range of possible time values;
+if you try to encode a time that is out of range, an error results.
+For instance, years before 1970 do not work on some systems;
+on others, years as early as 1901 do work.
+@end defun
+
+@node Time Parsing
+@section Parsing and Formatting Times
+
+ These functions convert time values (lists of two or three integers)
+to text in a string, and vice versa.
@defun date-to-time string
This function parses the time-string @var{string} and returns the
the inverse conversion, use @code{float-time}.
@end defun
-@defun decode-time &optional time
-This function converts a time value into calendrical information. If
-you don't specify @var{time}, it decodes the current time. The return
-value is a list of nine elements, as follows:
-
-@example
-(@var{seconds} @var{minutes} @var{hour} @var{day} @var{month} @var{year} @var{dow} @var{dst} @var{zone})
-@end example
-
-Here is what the elements mean:
-
-@table @var
-@item seconds
-The number of seconds past the minute, as an integer between 0 and 59.
-On some operating systems, this is 60 for leap seconds.
-@item minutes
-The number of minutes past the hour, as an integer between 0 and 59.
-@item hour
-The hour of the day, as an integer between 0 and 23.
-@item day
-The day of the month, as an integer between 1 and 31.
-@item month
-The month of the year, as an integer between 1 and 12.
-@item year
-The year, an integer typically greater than 1900.
-@item dow
-The day of week, as an integer between 0 and 6, where 0 stands for
-Sunday.
-@item dst
-@code{t} if daylight savings time is effect, otherwise @code{nil}.
-@item zone
-An integer indicating the time zone, as the number of seconds east of
-Greenwich.
-@end table
-
-@strong{Common Lisp Note:} Common Lisp has different meanings for
-@var{dow} and @var{zone}.
-@end defun
-
-@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, 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
-(as you would get from @code{current-time-zone}), a string as in the
-@code{TZ} environment variable, @code{t} for Universal Time, or an
-integer (as you would get from @code{decode-time}). The specified
-zone is used without any further alteration for daylight savings time.
-
-If you pass more than seven arguments to @code{encode-time}, the first
-six are used as @var{seconds} through @var{year}, the last argument is
-used as @var{zone}, and the arguments in between are ignored. This
-feature makes it possible to use the elements of a list returned by
-@code{decode-time} as the arguments to @code{encode-time}, like this:
-
-@example
-(apply 'encode-time (decode-time @dots{}))
-@end example
-
-You can perform simple date arithmetic by using out-of-range values for
-the @var{seconds}, @var{minutes}, @var{hour}, @var{day}, and @var{month}
-arguments; for example, day 0 means the day preceding the given month.
-
-The operating system puts limits on the range of possible time values;
-if you try to encode a time that is out of range, an error results.
-For instance, years before 1970 do not work on some systems;
-on others, years as early as 1901 do work.
-@end defun
-
@node Processor Run Time
@section Processor Run time
changes from user commands' changes and prevent a single undo entry
from growing to be quite large.
+ If a timer function calls functions that can change the match data,
+it should save and restore the match data. @xref{Saving Match Data}.
+
@deffn Command run-at-time time repeat function &rest args
This sets up a timer that calls the function @var{function} with
arguments @var{args} at time @var{time}. If @var{repeat} is a number
@code{key-translation-map}, even though they are overridden by it.
Indeed, actual key bindings override @code{function-key-map} and thus
may alter the key sequence that @code{key-translation-map} receives.
-Clearly, it is better to avoid to avoid this type of situation.
+Clearly, it is better to avoid this type of situation.
The intent of @code{key-translation-map} is for users to map one
character set to another, including ordinary characters normally bound