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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: Environment</TITLE><META NAME="description" CONTENT="Autoconf, Automake, and Libtool: Environment"><META NAME="keywords" CONTENT="Autoconf, Automake, and Libtool: Environment"><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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Although not directlyrelated to the implementation of the shell interpreter, thecharacteristics of some of target architectures do influence what isconsidered to be portable. To ensure your script will work on as manyshell implementations as possible, you must observe the followingpoints.</P><P><FONT SIZE="-1">SCO</FONT> Unix doesn't like <CODE>LANG=C</CODE> and friends, but without<CODE>LC_MESSAGES=C</CODE>, Solaris will translate variable values in<CODE>set</CODE>! Similarly, without <CODE>LC_CTYPE=C</CODE>, compiled C code canbehave unexpectedly. The trick is to set the values to <SAMP>`C'</SAMP>, exceptfor if they are not already set at all:</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>for var in LANG LC_ALL LC_MESSAGES LC_CTYPES LANGUAGESdo if eval test x"\${$var+set}" = xset; then eval $var=C; eval export $var fidone</pre></td></tr></table></P><P>HP-UX <CODE>ksh</CODE> and all POSIX shells print the targetdirectory to standard output if <SAMP>`CDPATH'</SAMP> is set.</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>if test x"${CDPATH+set}" = xset; then CDPATH=:; export CDPATH; fi</pre></td></tr></table></P><P>The target architecture file system may impose limits on your scripts.IF you want your scripts to run on the architectures which impose theselimits, then your script must adhere to these limits:</P><P><UL><LI>The ISO9660 filesystem, as used on most CD-ROMs, limits nesting ofdirectories to a maximum depth of twelve levels.<P><LI>Many old Unix filesystems place a 14 character limit on the length ofany filename. If you care about portability to <FONT SIZE="-1">DOS</FONT>,<EM>that</EM> has an 8 character limit with an optional extension of 3 orfewer characters (known as 8.3 notation).</UL><P>A useful idiom when you need to determine whether a particular pathnameis relative or absolute, which works for <FONT SIZE="-1">DOS</FONT> targets to follows:</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>case "$file" in [\\/]* | ?:[\\/]*) echo absolute ;; *) echo default ;;esac</pre></td></tr></table></P><P><A NAME="Utilities"></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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