<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<!--Converted with LaTeX2HTML 96.1-c (Feb 29, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds -->
<HTML>
<HEAD>
<TITLE>8.2.3 Look at a Terminal Description</TITLE>
<META NAME="description" CONTENT="8.2.3 Look at a Terminal Description">
<META NAME="keywords" CONTENT="lpg">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<LINK REL=STYLESHEET HREF="lpg.css">
</HEAD>
<BODY LANG="EN">
<A NAME="tex2html1543" HREF="node93.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="/icons//next_motif.gif"></A> <A NAME="tex2html1541" HREF="node89.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="/icons//up_motif.gif"></A> <A NAME="tex2html1535" HREF="node91.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="/icons//previous_motif.gif"></A> <A NAME="tex2html1545" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="/icons//contents_motif.gif"></A> <BR>
<B> Next:</B> <A NAME="tex2html1544" HREF="node93.html">8.2.4 Termcap Capabilities</A>
<B>Up:</B> <A NAME="tex2html1542" HREF="node89.html">8.2 The Termcap Library</A>
<B> Previous:</B> <A NAME="tex2html1536" HREF="node91.html">8.2.2 Find a Terminal </A>
<BR> <P>
<H2><A NAME="SECTION00923000000000000000">8.2.3 Look at a Terminal Description</A></H2>
<P>
Every piece of information is called a capability, every capability is
a two letter code, and every two letter code is followed by the value
for the capability. Possible types are:
<P>
<UL><LI> <B>Numeric</B>: For instance <I>co</I> - number of columns<LI> <B>Boolean</B> or <B>Flag</B>: For instance <I>hc</I> - hardcopy
terminal<LI> <B>String</B>: For instance <I>st</I> - set tab stop
</UL>
<P>
Each capability is associated with a single value type. (<I>co</I>
is always numeric, <I>hc</I> is always a flag and <I>st</I> is always a string).
There are three different types of values, so there are also three functions to
interrogate them. <TT>char *name</TT> is the two letter code for the capability.
<P>
<UL><LI> <TT>int tgetnum(char *name)</TT> <A NAME="fun_tgetnum"> </A><BR>
Get a capability value that is numeric, such as <I>co</I>.
<B>tgetnum(...)</B> returns the numeric value if the capability is
available, otherwise 1.
(Note: the returned value is not negative.)<LI> <TT>int tgetflag(char *name)</TT> <A NAME="fun_tgetflag"> </A><BR>
Get a capability value that is boolean (or flag).
Returns 1 if the flag is present, 0 otherwise.<LI> <TT>char *tgetstr(char *name, char **area)</TT> <A NAME="fun_tgetstr"> </A><BR>
Get a capability value that is a string. Returns a pointer to
the string or NULL if not present. In the GNU version, if
<TT>area</TT> is NULL, termcap will allocate memory by
itself. Termcap will never refer to this pointer again, so
don't forget to free <TT>name</TT> before leaving the
program. This method is preferred, because you don't know how
much space is needed for the pointer, so let termcap do this
for you.
</UL>
<P>
<P><P><BR> <HR>
<P><ADDRESS>
<I>Converted on: <BR>
Fri Mar 29 14:43:04 EST 1996</I>
</ADDRESS>
</BODY>
</HTML>
