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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node75.html b/sag-0.6.1-www/Invisible/sag-0.6/node75.html new file mode 100644 index 0000000..9f8e02b --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node75.html @@ -0,0 +1,96 @@ +<!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>Configuring init to start getty: the /etc/inittab file</TITLE> +<META NAME="description" CONTENT="Configuring init to start getty: the /etc/inittab file"> +<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="tex2html1257" HREF="node76.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1255" HREF="node73.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1249" HREF="node74.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1259" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1260" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1258" HREF="node76.html">Run levels</A> +<B>Up:</B> <A NAME="tex2html1256" HREF="node73.html">init</A> +<B> Previous:</B> <A NAME="tex2html1250" HREF="node74.html">init comes first</A> +<BR> <P> +<A NAME="2381"> </A><H1><A NAME="SECTION00820000000000000000">Configuring <tt>init</tt><A NAME="2377"> </A> to start <tt>getty</tt><A NAME="2379"> </A>: the <tt>/etc/inittab</tt> file</A></H1> +<P> + When it starts up, <tt>init</tt><A NAME="2383"> </A> reads the <tt>/etc/inittab</tt><A NAME="2385"> </A> + configuration file. While the system is running, it will + re-read it, if sent the HUP signal;<A NAME="tex2html33" HREF="footnode.html#2310"><IMG ALIGN=BOTTOM ALT="gif" SRC="./foot_motif.gif"></A> this feature makes it + unnecessary to boot the system to make changes to the <tt>init</tt><A NAME="2389"> </A> + configuration take effect. +<P> + The <tt>/etc/inittab</tt><A NAME="2391"> </A> file is a bit complicated. We'll start + with the simple case of configuring <tt>getty</tt><A NAME="2393"> </A> lines. Lines in + <tt>/etc/inittab</tt><A NAME="2395"> </A> consist of four colon-delimited fields: +<BLOCKQUOTE> <i>id:runlevels:action:process</i> +</BLOCKQUOTE> + The fields are described below. In addition, <tt>/etc/inittab</tt><A NAME="2397"> </A> + can contain empty lines, and lines that begin with a number + sign (`<code>#</code>'); these are both ignored. +<P> + <DL ><DT><STRONG>id</STRONG> +<DD> This identifies the line in the file. For + <tt>getty</tt><A NAME="2399"> </A> lines, it specifies the terminal + it runs on (the characters after <tt>/dev/tty</tt><A NAME="2401"> </A> + in the device file name). For other lines, + it doesn't matter (except for length restrictions), + but it should be unique. +<P> + <DT><STRONG>runlevels</STRONG> +<DD> + The run levels the line should be considered + for. The run levels are given as single digits, + without delimiters. (Run levels are described + in the next section.) +<P> + <DT><STRONG>action</STRONG> +<DD> What action should be taken by the line, e.g., + <tt>respawn</tt> to run the command in the + next field again, when it exits, or <tt>once</tt> + to run it just once. +<P> + <DT><STRONG>process</STRONG> +<DD> The command to run. +<P> +</DL> +<P> + To start a <tt>getty</tt><A NAME="2403"> </A> on the first virtual terminal + (<tt>/dev/tty1</tt><A NAME="2405"> </A>), in all the normal multi-user run levels + (2-5), one would write the following line: +<BLOCKQUOTE> <TT> +1:2345:respawn:/sbin/getty 9600 tty1 +</TT></BLOCKQUOTE> + The first field says that this is the line for <tt>/dev/tty1</tt><A NAME="2407"> </A>. + The second field says that it applies to run levels 2, 3, 4, + and 5. The third field means that the command should be run + again, after it exits (so that one can log in, log out, and + then log in again). The last field is the command that runs + <tt>getty</tt><A NAME="2409"> </A> on the first virtual terminal.<A NAME="tex2html34" HREF="footnode.html#2311"><IMG ALIGN=BOTTOM ALT="gif" SRC="./foot_motif.gif"></A> +<P> + If you wanted to add terminals or dial-in modem lines to a system, + you'd add more lines to <tt>/etc/inittab</tt><A NAME="2413"> </A>, one for each terminal + or dial-in line. For more details, see the manual pages + <em>init</em><A NAME="2415"> </A>(8), <em>inittab</em><A NAME="2417"> </A>(5), and <em>getty</em><A NAME="2419"> </A>(8). +<P> + If a command fails when it starts, and <tt>init</tt><A NAME="2421"> </A> is configured + to <tt>restart</tt> it, it will use a lot of system resources: + <tt>init</tt><A NAME="2423"> </A> starts it, it fails, <tt>init</tt><A NAME="2425"> </A> starts it, it fails, + <tt>init</tt><A NAME="2427"> </A> starts it, it fails, and so on, ad infinitum. To + prevent this, <tt>init</tt><A NAME="2429"> </A> will keep track of how often it restarts + a command, and if the frequency grows to high, it will delay for + five minutes before restarting again. +<P> +<HR><A NAME="tex2html1257" HREF="node76.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1255" HREF="node73.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1249" HREF="node74.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1259" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1260" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1258" HREF="node76.html">Run levels</A> +<B>Up:</B> <A NAME="tex2html1256" HREF="node73.html">init</A> +<B> Previous:</B> <A NAME="tex2html1250" HREF="node74.html">init comes first</A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |