58 lines
3.1 KiB
HTML
58 lines
3.1 KiB
HTML
<!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>10.1 Introduction</TITLE>
|
|
<META NAME="description" CONTENT="10.1 Introduction">
|
|
<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="tex2html2053" HREF="node138.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="next_motif.gif"></A> <A NAME="tex2html2051" HREF="node136.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="up_motif.gif"></A> <A NAME="tex2html2045" HREF="node136.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="previous_motif.gif"></A> <A NAME="tex2html2055" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="contents_motif.gif"></A> <BR>
|
|
<B> Next:</B> <A NAME="tex2html2054" HREF="node138.html">10.2 Signal handling</A>
|
|
<B>Up:</B> <A NAME="tex2html2052" HREF="node136.html">10 Porting Applications to </A>
|
|
<B> Previous:</B> <A NAME="tex2html2046" HREF="node136.html">10 Porting Applications to </A>
|
|
<BR> <P>
|
|
<H1><A NAME="SECTION001110000000000000000">10.1 Introduction</A></H1>
|
|
<P>
|
|
Porting UNIX applications to the Linux operating system is remarkably
|
|
easy. Linux, and the GNU C library used by it, have been designed with
|
|
applications portability in mind, meaning that many applications will
|
|
compile simply by issuing <TT>make</TT>. Those which don't generally
|
|
use some obscure feature of a particular implementation, or rely
|
|
strongly on undocumented or undefined behavior of, say, a particular
|
|
system call.
|
|
<P>
|
|
Linux is mostly compliant with IEEE Std 1003.1-1988 (POSIX.1), but
|
|
has not actually been certified as such. Similarly, Linux also
|
|
implements many features found in the SVID and BSD strains of UNIX,
|
|
but again does not necessarily adhere to them in all cases. In general,
|
|
Linux has been designed to be compatible with other UNIX implementations,
|
|
to make applications porting easier, and in a number of instances has
|
|
improved upon or corrected behavior found in those implementations.
|
|
<P>
|
|
As an example, the <EM>timeout</EM> argument passed to the <EM>select</EM>
|
|
system call is actually decremented during the poll operation by Linux.
|
|
Other implementations don't modify this value at all, and applications
|
|
which aren't expecting this could break when compiled under Linux.
|
|
The BSD and SunOS man pages for <EM>select</EM> warn that
|
|
in a ``future implementation'', the system call may modify the
|
|
timeout pointer. Unfortunately, many applications still assume
|
|
that the value will be untouched.
|
|
<P>
|
|
The goal of this paper is to provide an overview of the major
|
|
issues associated with porting applications to Linux, highlighting
|
|
the differences between Linux, POSIX.1, SVID, and BSD in the
|
|
following areas: signal handling, terminal I/O, process control
|
|
and information gathering, and portable conditional compilation.
|
|
<P>
|
|
<BR> <HR>
|
|
<P><ADDRESS>
|
|
<I>Converted on: <BR>
|
|
Fri Mar 29 14:43:04 EST 1996</I>
|
|
</ADDRESS>
|
|
</BODY>
|
|
</HTML>
|