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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node109.html b/sag-0.6.1-www/Invisible/sag-0.6/node109.html new file mode 100644 index 0000000..b7b2d30 --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node109.html @@ -0,0 +1,94 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>Showing and setting time</TITLE> +<META NAME="description" CONTENT="Showing and setting time"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html1687" HREF="node110.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1685" HREF="node106.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1679" HREF="node108.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1689" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1690" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1688" HREF="node110.html">When the clock is </A> +<B>Up:</B> <A NAME="tex2html1686" HREF="node106.html">Keeping Time</A> +<B> Previous:</B> <A NAME="tex2html1680" HREF="node108.html">The hardware and software </A> +<BR> <P> +<H1><A NAME="SECTION001230000000000000000">Showing and setting time</A></H1> +<P> + In the Debian system, the system time zone is determined by the + symbolic link <tt>/etc/localtime</tt><A NAME="3159"> </A>. This link points at a time + zone data file that describes the local time zone. The time + zone data files are stored in <tt>/usr/lib/zoneinfo</tt><A NAME="3161"> </A>. + Other Linux distributions may do this differently. +<P> + A user can change his private time zone by setting the + TZ environment variable. If it is unset, the system time zone + is assumed. The syntax of the TZ variable is described in + the <em>tzset</em><A NAME="3163"> </A>(3) manual page. +<P> + The <tt>date</tt><A NAME="3165"> </A> command shows the current date and + time.<A NAME="tex2html54" HREF="footnode.html#3157"><IMG ALIGN=BOTTOM ALT="gif" SRC="./foot_motif.gif"></A> For example: +<BLOCKQUOTE> <TT> +<code>$</code> <i>date</i> <BR> +<code>Sun Jul 14 21:53:41 EET DST 1996</code> <BR> +<code>$</code> +</TT></BLOCKQUOTE> + That time is Sunday, 14th of July, 1996, at about ten before + ten at the evening, in the time zone called ``EET DST'' + (which might be East European Daylight Savings Time). + <tt>date</tt><A NAME="3169"> </A> can also show the univeral time: +<BLOCKQUOTE> <TT> +<code>$</code> <i>date -u</i> <BR> +<code>Sun Jul 14 18:53:42 UTC 1996</code> <BR> +<code>$</code> +</TT></BLOCKQUOTE> + <tt>date</tt><A NAME="3171"> </A> is also used to set the kernel's software clock: +<BLOCKQUOTE> <TT> +<code>#</code> <i>date 07142157</i> <BR> +<code>Sun Jul 14 21:57:00 EET DST 1996</code> <BR> +<code>#</code> <i>date</i> <BR> +<code>Sun Jul 14 21:57:02 EET DST 1996</code> <BR> +<code>#</code> +</TT></BLOCKQUOTE> + See the <tt>date</tt><A NAME="3173"> </A> manual page for more details--the syntax + is a bit arcane. Only <tt>root</tt> can set the time. While + each user can have his own time zone, the clock is the same for + everyone. +<P> + <tt>date</tt><A NAME="3175"> </A> only shows or sets the software clock. + The <tt>clock</tt><A NAME="3177"> </A> commands syncronizes the hardware and + software clocks. + It is used when the system boots, to read the hardware clock + and set the software clock. If you need to set both clocks, you + first set the software clock with <tt>date</tt><A NAME="3179"> </A>, and then the + hardware clock with <tt>clock -w</tt>. +<P> + The <tt>-u</tt> option to <tt>clock</tt><A NAME="3181"> </A> tells it that the + hardware clock is in universal time. + You <em>must</em> use the <tt>-u</tt> option correctly. If you + don't, your computer will be quite confused about what the + time is. +<P> + The clocks should be changed with care. Many parts of + a Unix system require the clocks to work correctly. For example, + the <tt>cron</tt><A NAME="3183"> </A> daemon runs commands periodically. If you change + the clock, it can be confused of whether it needs to run the + commands or not. On one early Unix system, someone set the + clock twenty years into the future, and <tt>cron</tt><A NAME="3185"> </A> wanted to + run all the periodic commands for twenty years all at once. + Current versions of <tt>cron</tt><A NAME="3187"> </A> can handle this correctly, but + you should still be careful. Big jumps or backward jumps are + more dangeours than smaller or forward ones. +<P> +<HR><A NAME="tex2html1687" HREF="node110.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1685" HREF="node106.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1679" HREF="node108.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1689" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1690" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1688" HREF="node110.html">When the clock is </A> +<B>Up:</B> <A NAME="tex2html1686" HREF="node106.html">Keeping Time</A> +<B> Previous:</B> <A NAME="tex2html1680" HREF="node108.html">The hardware and software </A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |