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<HTML><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><!-- Created on September, 12 2004 by texi2html 1.64 --><!-- Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author) Karl Berry <karl@freefriends.org> Olaf Bachmann <obachman@mathematik.uni-kl.de> and many others.Maintained by: Olaf Bachmann <obachman@mathematik.uni-kl.de>Send bugs and suggestions to <texi2html@mathematik.uni-kl.de> --><HEAD><TITLE>Autoconf, Automake, and Libtool: Unix Diversity</TITLE><META NAME="description" CONTENT="Autoconf, Automake, and Libtool: Unix Diversity"><META NAME="keywords" CONTENT="Autoconf, Automake, and Libtool: Unix Diversity"><META NAME="resource-type" CONTENT="document"><META NAME="distribution" CONTENT="global"><META NAME="Generator" CONTENT="texi2html 1.64"><script language="Javascript"><!-- // Check the browser version. function checkVersion() { if (navigator.appVersion.charAt(0)>=3) return true; if (navigator.appVersion.charAt(0)>=4) return true; else return false; } if (checkVersion()) { homeon = new Image(); 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document [imgName].src = imgOff; } }// --></SCRIPT></HEAD><BODY LANG="EN" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#6688AA" VLINK="#336688" ALINK="#808080"><A NAME="SEC7"></A><TABLE BORDER=0 CELLPADDING=0 CELLSPACING=10><TR VALIGN="TOP"><TD ALIGN="MIDDLE" WIDTH=50 BGCOLOR="#e6e6e6"><TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_6.html#SEC6" onMouseover="img_act('prev')" onMouseout="img_inact('prev')"><IMG SRC="prev.png" BORDER="0" ALT="Back: History" ALIGN="MIDDLE" NAME="prev"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_8.html#SEC8" onMouseover="img_act('next')" onMouseout="img_inact('next')"><IMG SRC="next.png" BORDER="0" ALT="Forward: First Configure Programs" ALIGN="MIDDLE" NAME="next"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"> <TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_6.html#SEC6" onMouseover="img_act('back')" onMouseout="img_inact('back')"><IMG SRC="back.png" BORDER="0" ALT="FastBack: History" ALIGN="MIDDLE" NAME="back"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_6.html#SEC6" onMouseover="img_act('up')" onMouseout="img_inact('up')"><IMG SRC="up.png" BORDER="0" ALT="Up: History" ALIGN="MIDDLE" NAME="up"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_13.html#SEC13" onMouseover="img_act('forward')" onMouseout="img_inact('forward')"><IMG SRC="forward.png" BORDER="0" ALT="FastForward: Invoking configure" ALIGN="MIDDLE" NAME="forward"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook.html#SEC_Top" onMouseover="img_act('home')" onMouseout="img_inact('home')"><IMG SRC="home.png" BORDER="0" ALT="Top: Autoconf, Automake, and Libtool" ALIGN="MIDDLE" NAME="home"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_toc.html#SEC_Contents" onMouseover="img_act('toc')" onMouseout="img_inact('toc')"><IMG SRC="toc.png" BORDER="0" ALT="Contents: Table of Contents" ALIGN="MIDDLE" NAME="toc"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_285.html#SEC285" onMouseover="img_act('index')" onMouseout="img_inact('index')"><IMG SRC="index.png" BORDER="0" ALT="Index: Index" ALIGN="MIDDLE" NAME="index"></A></TD></TR><TR VALIGN="TOP" ALIGN="LEFT"><TD VALIGN="MIDDLE" ALIGN="LEFT"><A HREF="autobook_abt.html#SEC_About" onMouseover="img_act('help')" onMouseout="img_inact('help')"><IMG SRC="help.png" BORDER="0" ALT="About: About this document" ALIGN="MIDDLE" NAME="help"></A></TD></TR></TABLE></TD><TD ALIGN="LEFT"><H2> 2.1 The Diversity of Unix Systems </H2><!--docid::SEC7::--><P>Of the programs discussed in this book, the first to be developed wasAutoconf. Its development was determined by the history of the Unixoperating system.</P><P>The first version of Unix was written by Dennis Ritchie and Ken Thompsonat Bell Labs in 1969. During the 1970s, Bell Labs was not permitted tosell Unix commercially, but did distribute Unix to universities atrelatively low cost. The University of California at Berkeley addedtheir own improvements to the Unix sources; the result was known as the<FONT SIZE="-1">BSD</FONT> version of Unix.</P><P>In the early 1980s, <FONT SIZE="-1">AT&T</FONT> signed an agreement permitting themto sell Unix commercially. The first <FONT SIZE="-1">AT&T</FONT> version of Unix wasknown as System III.</P><P>As the popularity of Unix increased during the 1980s, several othercompanies modified the Unix sources to create their own variants.Examples include SunOS from Sun Microsystems, Ultrix from DigitalEquipment Corporation, and HP-UX from Hewlett Packard.</P><P>Although all of the Unix variants were fundamentally similar, there werevarious differences between them. They had slightly different sets ofheader files and slightly different lists of functions in the systemlibraries, as well as more significant differences in areas such asterminal handling and job control.</P><P>The emerging POSIX standards helped to eliminate some of thesedifferences. However, in some areas POSIX introduced new features,leading to more variants. Also, different systems adopted thePOSIX standard at different times, leading to further disparities.</P><P>All of these variations caused problems for programs distributed assource code. Even a function as straightforward as <CODE>memcpy</CODE> wasnot available everywhere; the <FONT SIZE="-1">BSD</FONT> system library provided thesimilar function <CODE>bcopy</CODE> instead, but the order of arguments wasreversed.</P><P>Program authors who wanted their programs to run on a wide variety ofUnix variants had to be familiar with the detailed differences betweenthe variants. They also had to worry about the ways in which thevariants changed from one version to another, as variants on the onehand converged on the POSIX standard and on the other continued tointroduce new and different features.</P><P>While it was generally possible to use <CODE>#ifdef</CODE> to identifyparticular systems and versions, it became increasingly difficult toknow which versions had which features. It became clear that some moreorganized approach was needed to handle the differences between Unixvariants.</P><P><A NAME="First Configure Programs"></A></TR></TABLE><BR> <FONT SIZE="-1">This document was generatedby <I>Gary V. Vaughan</I> on <I>September, 12 2004</I>using <A HREF="http://www.mathematik.uni-kl.de/~obachman/Texi2html"><I>texi2html</I></A></BODY></HTML>⌨️ 快捷键说明
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