📄 segv.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3O//DTD W3 HTML 2.0//EN"><!-- This collection of hypertext pages is Copyright 1995-2005 by Steve Summit. --><!-- Content from the book "C Programming FAQs: Frequently Asked Questions" --><!-- (Addison-Wesley, 1995, ISBN 0-201-84519-9) is made available here by --><!-- permission of the author and the publisher as a service to the community. --><!-- It is intended to complement the use of the published text --><!-- and is protected by international copyright laws. --><!-- The on-line content may be accessed freely for personal use --><!-- but may not be published or retransmitted without explicit permission. --><!-- --><!-- this page built Sat Dec 24 21:47:46 2005 by faqproc version 2.7 --><!-- from source file strangeprob.sgml dated Tue Jun 29 21:44:40 2004 --><!-- corresponding to FAQ list version 4.0 --><html><!-- Mirrored from c-faq.com/strangeprob/segv.html by HTTrack Website Copier/3.x [XR&CO'2008], Sat, 14 Mar 2009 07:59:01 GMT --><head><meta name=GENERATOR content="faqproc"><title>Question 16.8</title><link href="ptralign.html" rev=precedes><link href="../style/layout.html" rel=precedes><link href="index.html" rev=subdocument></head><body bgcolor="#ffffff"><a href="ptralign.html" rev=precedes><img src="../images/buttonleft.gif" alt="prev"></a><a href="index.html" rev=subdocument><img src="../images/buttonup.gif" alt="up"></a><a href="../style/layout.html" rel=precedes><img src="../images/buttonright.gif" alt="next"></a> <a href="../index-2.html"><img src="../images/buttontop.gif" alt="top/contents"></a><a href="../search.html"><img src="../images/buttonsrch.gif" alt="search"></a><hr><p><!-- qbegin --><h1>comp.lang.c FAQ list<font color=blue>·</font><!-- qtag -->Question 16.8</h1><p><font face=Helvetica size=8 color=blue><b>Q:</b></font>Whatdo``Segmentation violation'',``Bus error'',and``General protection fault''mean?What's a ``core dump''?</p><p><hr><p><font face=Helvetica size=8 color=blue><b>A:</b></font>Thesesymptoms(andany similar messageshaving to do withmemory access violations or protection faults)generallymeanthat your program tried to access memory it shouldn'thave,invariablyas a result ofstack corruptionorimproper pointer use.Likely causes are:<UL><li>overflow of local(``automatic,'' stack-allocated)arrays<li>inadvertent use of null pointers(see also questions <a href="../null/null2.html">5.2</a> and <a href="../null/nullpassign.html">5.20</a>)<li>uninitialized,misaligned,or otherwiseimproperly allocatedpointers(seequestions <a href="../malloc/malloc1.html">7.1</a>, <a href="../malloc/malloc2.html">7.2</a>, and <a href="ptralign.html">16.7</a>)<li>stale aliases to memory that has been relocated(see question <a href="../malloc/realloc.html">7.29</a>)<li>corruption of the<TT>malloc</TT> arena(see question<a href="../malloc/crash.html">7.19</a>)<li>attempts to modify read-only values(those declared <TT>const</TT>,and string literals--see question <a href="../decl/strlitinit.html">1.32</a>)<li>mismatched function arguments,especially involving pointers;twopossibilities are<TT>scanf</TT>(see question<a href="../stdio/scanf1.html">12.12</a>)and<TT>fprintf</TT>(make sure it receives its first<TT>FILE *</TT> argument)</UL></p><p>Under Unix,any of these problems almost invariably leads toa ``core dump'':a filenamed <TT>core</TT>,<a href="ferrite.html" rel=subdocument>[footnote]</a>created in the current directory,containing a memory image of the crashed process,for debugging.</p><p>The distinction between``Bus error'' and ``Segmentation Violation''may or may not be significant;different versions of Unix generate thesesignalsunder different sets of circumstances.Roughly speaking,a segmentation violationindicates an attempt to access memory which doesn't even exist,and a bus errorindicates an attempt to access memory in an illegal way(perhaps due to an unaligned pointer;see question <a href="ptralign.html">16.7</a>).</p><p>See also questions <a href="biglocal.html">16.3</a>and<a href="crashatexit.html">16.4</a>.</p><!-- aend --><p><hr><a href="ptralign.html" rev=precedes><img src="../images/buttonleft.gif" alt="prev"></a><a href="index.html" rev=subdocument><img src="../images/buttonup.gif" alt="up"></a><a href="../style/layout.html" rel=precedes><img src="../images/buttonright.gif" alt="next"></a> <a href="../questions.html"><img src="../images/buttontop.gif" alt="contents"></a><a href="../search.html"><img src="../images/buttonsrch.gif" alt="search"></a><br><!-- lastfooter --><a href="../about.html">about this FAQ list</a> <a href="../eskimo.html">about eskimo</a> <a href="../search.html">search</a> <a href="../feedback.html">feedback</a> <a href="copyright.html">copyright</a><p>Hosted by<a href="http://www.eskimo.com/"><img src="../../www.eskimo.com/img/link/eskitiny.gif" alt="Eskimo North"></a></body><!-- Mirrored from c-faq.com/strangeprob/segv.html by HTTrack Website Copier/3.x [XR&CO'2008], Sat, 14 Mar 2009 07:59:01 GMT --></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 + -