一、初识GDB（Linux下调试工具GDB教程）
一、初识GDB（Linux下调试工具GDB教程）
1.GDB概述
2.调试示例
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1.GDB概述
<wbr><wbr><wbr>GDB是GNU开源组织发布的一个强大的UNIX下的程序调试工具。或许，各位比较喜欢那种图形界面方式的，像VC、BCB等IDE的调试，但如果你是在UNIX平台下做软件，你会发现GDB这个调试工具有比VC、BCB的图形化调试器更强大的功能。所谓“寸有所长，尺有所短”就是这个道理。</wbr></wbr></wbr>
一般来说，GDB主要帮忙你完成下面四个方面的功能：
<wbr><wbr><wbr>1、启动你的程序，可以按照你的自定义的要求随心所欲的运行程序。<br><wbr><wbr><wbr>2、可让被调试的程序在你所指定的调置的断点处停住。（断点可以是条件表达式）<br><wbr><wbr><wbr>3、当程序被停住时，可以检查此时你的程序中所发生的事。<br><wbr><wbr><wbr>4、动态的改变你程序的执行环境。</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>
从上面看来，GDB和一般的调试工具没有什么两样，基本上也是完成这些功能，不过在细节上，你会发现GDB这个调试工具的强大，大家可能比较习惯了图形化的调试工具，但有时候，命令行的调试工具却有着图形化工具所不能完成的功能。让我们一一看来。
2.调试示例
<wbr><wbr> 源程序：tst.c</wbr></wbr>
<wbr><wbr><wbr><wbr>1 #include <stdio.h><br><wbr><wbr><wbr><wbr>2<br><wbr><wbr><wbr><wbr>3 int func(int n)<br><wbr><wbr><wbr><wbr>4 {<br><wbr><wbr><wbr><wbr>5<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>int sum=0,i;<br><wbr><wbr><wbr><wbr>6<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>for(i=0; i<n; i++)<br><wbr><wbr><wbr><wbr>7<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>{<br><wbr><wbr><wbr><wbr>8<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>sum+=i;<br><wbr><wbr><wbr><wbr>9<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}<br><wbr><wbr><wbr>10<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>return sum;<br><wbr><wbr><wbr> 11 }<br><wbr><wbr><wbr> 12<br><wbr><wbr><wbr> 13<br><wbr><wbr><wbr> 14main()<br><wbr><wbr><wbr> 15 {<br><wbr><wbr><wbr>16<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>int i;<br><wbr><wbr><wbr>17<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>long result = 0;<br><wbr><wbr><wbr>18<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>for(i=1; i<=100; i++)<br><wbr><wbr><wbr>19<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>{<br><wbr><wbr><wbr>20<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>result += i;<br><wbr><wbr><wbr>21<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}<br><wbr><wbr><wbr> 22<br><wbr><wbr><wbr>23<wbr><wbr><wbr><wbr><wbr><wbr><wbr>printf(“result[1-100] = %d /n”, result );<br><wbr><wbr><wbr>24<wbr><wbr><wbr><wbr><wbr><wbr><wbr>printf(“result[1-250] = %d /n”, func(250) );<br><wbr><wbr><wbr> 25 }</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>
编译生成执行文件：（Linux下）
<wbr><wbr><wbr>hchen/test> cc -g tst.c -o tst</wbr></wbr></wbr>
使用GDB调试：
hchen/test> gdb tst<wbr><———- 启动GDB<br> GNU gdb 5.1.1<br> Copyright 2002 Free Software Foundation, Inc.<br> GDB is free software, covered by the GNU General Public License,and you are<br> welcome to change it and/or distribute copies of it under certainconditions.<br> Type “show copying” to see the conditions.<br> There is absolutely no warranty for GDB.<wbr> Type“show warranty” for details.<br> This GDB was configured as “i386-suse-linux”…<br> (gdb)l<wbr><wbr><wbr><wbr><——————– l命令相当于list，从第一行开始例出原码。<br> 1<wbr><wbr><wbr><wbr><wbr><wbr><wbr>#include <stdio.h><br> 2<br> 3<wbr><wbr><wbr><wbr><wbr><wbr><wbr>int func(int n)<br> 4<wbr><wbr><wbr><wbr><wbr><wbr><wbr>{<br> 5<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>int sum=0,i;<br> 6<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>for(i=0; i<n; i++)<br> 7<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>{<br> 8<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>sum+=i;<br> 9<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}<br> 10<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>return sum;<br> (gdb)<wbr><wbr><wbr><wbr><wbr><wbr><——————– 直接回车表示，重复上一次命令<br> 11<wbr><wbr><wbr><wbr><wbr><wbr>}<br> 12<br> 13<br> 14<wbr><wbr><wbr><wbr><wbr><wbr>main()<br> 15<wbr><wbr><wbr><wbr><wbr><wbr>{<br> 16<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>int i;<br> 17<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>long result = 0;<br> 18<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>for(i=1; i<=100; i++)<br> 19<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>{<br> 20<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>result += i;<wbr><wbr><br> (gdb) break16<wbr><wbr><wbr><——————– 设置断点，在源程序第16行处。<br> Breakpoint 1 at 0×8048496: file tst.c, line 16.<br> (gdb) break func<wbr> <——————–设置断点，在函数func()入口处。<br> Breakpoint 2 at 0×8048456: file tst.c, line 5.<br> (gdb) info break<wbr> <——————–查看断点信息。<br> NumType<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>Disp EnbAddress<wbr><wbr><wbr>What<br> 1<wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>