old-www/HOWTO/Remote-Serial-Console-HOWTO/getty.html

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>Configure getty</TITLE
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><DIV
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><H1
><A
NAME="GETTY"
></A
>Chapter 6. Configure <SPAN
CLASS="PRODUCTNAME"
>getty</SPAN
></H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
>6.1. <A
HREF="getty-init.html"
><SPAN
CLASS="PRODUCTNAME"
>init</SPAN
> system</A
></DT
><DT
>6.2. <A
HREF="getty-getty.html"
>Traditional <SPAN
CLASS="PRODUCTNAME"
>getty</SPAN
></A
></DT
><DT
>6.3. <A
HREF="getty-agetty.html"
><SPAN
CLASS="PRODUCTNAME"
>agetty</SPAN
></A
></DT
><DT
>6.4. <A
HREF="getty-mgetty.html"
><SPAN
CLASS="PRODUCTNAME"
>mgetty</SPAN
></A
></DT
><DT
>6.5. <A
HREF="getty-mingetty.html"
><SPAN
CLASS="PRODUCTNAME"
>mingetty</SPAN
></A
></DT
><DT
>6.6. <A
HREF="getty-none.html"
>No <SPAN
CLASS="PRODUCTNAME"
>getty</SPAN
></A
></DT
></DL
></DIV
><P
><SPAN
CLASS="APPLICATION"
>getty</SPAN
> monitors serial lines,
waiting for a connection. It then configures the serial link, sends
the contents of <TT
CLASS="FILENAME"
>/etc/issue</TT
>, and asks the person
connecting for their login name. <SPAN
CLASS="APPLICATION"
>getty</SPAN
>
then starts <SPAN
CLASS="APPLICATION"
>login</SPAN
> and
<SPAN
CLASS="APPLICATION"
>login</SPAN
> asks the person for their password.
If the user does nothing, <SPAN
CLASS="APPLICATION"
>getty</SPAN
> or
<SPAN
CLASS="APPLICATION"
>login</SPAN
> hang up and
<SPAN
CLASS="APPLICATION"
>getty</SPAN
> goes back to waiting.</P
><P
>The <SPAN
CLASS="APPLICATION"
>getty</SPAN
> command has been
re-implemented numerous times. There is a wide selection of
<SPAN
CLASS="APPLICATION"
>getty</SPAN
> clones, each with slight
differences in behavior and syntax. We will describe the
traditional <SPAN
CLASS="APPLICATION"
>getty</SPAN
>, and then some popular
alternatives.</P
><P
>One of the jobs of a <SPAN
CLASS="APPLICATION"
>getty</SPAN
> is to
set the <TT
CLASS="VARNAME"
>TERM</TT
> environment variable to indicate the
make and model of the terminal which is connecting. In this
<I
CLASS="CITETITLE"
>HOWTO</I
> we set the terminal to the commonly
emulated <SPAN
CLASS="PRODUCTNAME"
><SPAN
CLASS="ACRONYM"
>DEC</SPAN
>
<SPAN
CLASS="ACRONYM"
>VT100</SPAN
></SPAN
>. If you occassionally
connect using a different terminal emulation then you can
interactively change your choice of terminal by setting
<TT
CLASS="VARNAME"
>TERM</TT
> to the appropiate terminal listed in
<TT
CLASS="FILENAME"
>/etc/termcap</TT
>.</P
><DIV
CLASS="FIGURE"
><A
NAME="GETTY-TERM"
></A
><P
><B
>Figure 6-1. Interactively altering the connecting terminal's make and
model</B
></P
><TABLE
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BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="SCREEN"
><TT
CLASS="PROMPT"
>bash$</TT
> <B
CLASS="COMMAND"
>TERM=kermit</B
>
<TT
CLASS="PROMPT"
>bash$</TT
> <B
CLASS="COMMAND"
>tset -r</B
></PRE
></FONT
></TD
></TR
></TABLE
></DIV
><P
>A <SPAN
CLASS="APPLICATION"
>getty</SPAN
> is also responsible for
setting the time zone when a permanently-connected remote terminal
is located beyond the machine's default time zone. The
<SPAN
CLASS="APPLICATION"
>getty</SPAN
> overrides the default timezone by
setting the <TT
CLASS="ENVAR"
>TZ</TT
> environment variable. As with the
<TT
CLASS="ENVAR"
>TERM</TT
> environment variable, a user connecting from a
modem can interactively override the default time zone.</P
><DIV
CLASS="FIGURE"
><A
NAME="GETTY-TZ"
></A
><P
><B
>Figure 6-2. Interactively altering the connecting terminal's time zone</B
></P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="SCREEN"
><TT
CLASS="PROMPT"
>bash$</TT
> <B
CLASS="COMMAND"
>TZ=Australia/Adelaide</B
>
<TT
CLASS="PROMPT"
>bash$</TT
> <B
CLASS="COMMAND"
>export TZ</B
></PRE
></FONT
></TD
></TR
></TABLE
></DIV
><P
>If you do not know your time zone name, run the
<B
CLASS="COMMAND"
>tzselect</B
> utility to generate the appropiate
contents for <TT
CLASS="ENVAR"
>TZ</TT
>.</P
><P
>But first, let's see how <SPAN
CLASS="APPLICATION"
>getty</SPAN
> gets
started in the first place.</P
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