📄 ch32_05.htm
字号:
<html><head><title>CGI::Carp (Programming Perl)</title><!-- STYLESHEET --><link rel="stylesheet" type="text/css" href="../style/style1.css"><!-- METADATA --><!--Dublin Core Metadata--><meta name="DC.Creator" content=""><meta name="DC.Date" content=""><meta name="DC.Format" content="text/xml" scheme="MIME"><meta name="DC.Generator" content="XSLT stylesheet, xt by James Clark"><meta name="DC.Identifier" content=""><meta name="DC.Language" content="en-US"><meta name="DC.Publisher" content="O'Reilly & Associates, Inc."><meta name="DC.Source" content="" scheme="ISBN"><meta name="DC.Subject.Keyword" content=""><meta name="DC.Title" content="CGI::Carp"><meta name="DC.Type" content="Text.Monograph"></head><body><!-- START OF BODY --><!-- TOP BANNER --><img src="gifs/smbanner.gif" usemap="#banner-map" border="0" alt="Book Home"><map name="banner-map"><AREA SHAPE="RECT" COORDS="0,0,466,71" HREF="index.htm" ALT="Programming Perl"><AREA SHAPE="RECT" COORDS="467,0,514,18" HREF="jobjects/fsearch.htm" ALT="Search this book"></map><!-- TOP NAV BAR --><div class="navbar"><table width="515" border="0"><tr><td align="left" valign="top" width="172"><a href="ch32_04.htm"><img src="../gifs/txtpreva.gif" alt="Previous" border="0"></a></td><td align="center" valign="top" width="171"><a href="ch32_01.htm">Chapter 32: Standard Modules</a></td><td align="right" valign="top" width="172"><a href="ch32_06.htm"><img src="../gifs/txtnexta.gif" alt="Next" border="0"></a></td></tr></table></div><hr width="515" align="left"><!-- SECTION BODY --><h2 class="sect1">32.5. CGI::Carp</h2><a name="INDEX-5807"></a><blockquote><pre class="programlisting">use CGI::Carp;warn "This is a complaint"; # Stamp it with progname and date.die "But this one is serious"; # But don't cause server 500 errors.use CGI::Carp qw(carpout); # Import this function.open(LOG, ">>/var/tmp/mycgi-log") or die "Can't append to mycgi-log: $!\n";carpout(*LOG); # Now uses program-specific errlog.use CGI::Carp qw(fatalsToBrowser);die "Fatal error messages are now sent to browser, too";</pre></blockquote><p><a name="INDEX-5808"></a>The <tt class="literal">CGI::Carp</tt> module provides versions of the<tt class="literal">warn</tt> and <tt class="literal">die</tt> Perl built-infunctions, plus the <tt class="literal">Carp</tt> module's<tt class="literal">carp</tt>, <tt class="literal">cluck</tt>,<tt class="literal">confess</tt>, and <tt class="literal">croak</tt> functionswhich are more verbose and safer, too. They're more verbose becauseeach message includes the date and time with the name of the programissuing the message, which helps when you're using a log file sharedby a hundred different programs scribbling a thousand differentmessages on it at the same time.</p><p>The module is also kinder to web surfers, since premature death in aCGI script tends to cause inscrutable "<tt class="literal">Server 500</tt>" errors when theproper HTTP header doesn't get out to the server before your programpegs out, and this module makes sure that doesn't happen. The<tt class="literal">carpout</tt> function redirects all warnings and errors to the filehandlespecified. The <tt class="literal">fatalsToBrowser</tt> directive sends a copy of suchmessages to the user's browser, too. These facilities ease debuggingof problems in CGI scripts.</p><!-- BOTTOM NAV BAR --><hr width="515" align="left"><div class="navbar"><table width="515" border="0"><tr><td align="left" valign="top" width="172"><a href="ch32_04.htm"><img src="../gifs/txtpreva.gif" alt="Previous" border="0"></a></td><td align="center" valign="top" width="171"><a href="index.htm"><img src="../gifs/txthome.gif" alt="Home" border="0"></a></td><td align="right" valign="top" width="172"><a href="ch32_06.htm"><img src="../gifs/txtnexta.gif" alt="Next" border="0"></a></td></tr><tr><td align="left" valign="top" width="172">32.4. CGI</td><td align="center" valign="top" width="171"><a href="index/index.htm"><img src="../gifs/index.gif" alt="Book Index" border="0"></a></td><td align="right" valign="top" width="172">32.6. Class::Struct</td></tr></table></div><hr width="515" align="left"><!-- LIBRARY NAV BAR --><img src="../gifs/smnavbar.gif" usemap="#library-map" border="0" alt="Library Navigation Links"><p><font size="-1"><a href="copyrght.htm">Copyright © 2001</a> O'Reilly & Associates. All rights reserved.</font></p><map name="library-map"> <area shape="rect" coords="2,-1,79,99" href="../index.htm"><area shape="rect" coords="84,1,157,108" href="../perlnut/index.htm"><area shape="rect" coords="162,2,248,125" href="../prog/index.htm"><area shape="rect" coords="253,2,326,130" href="../advprog/index.htm"><area shape="rect" coords="332,1,407,112" href="../cookbook/index.htm"><area shape="rect" coords="414,2,523,103" href="../sysadmin/index.htm"></map><!-- END OF BODY --></body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -