valgrind基本使用

1。valgrind是一个内存检测工具，类似的还有purify,insure++等

2。测试文件test.c

　　test.c :

　　　　main(){

　　　　　　int＊ a=new int[100];

　　　　　　return 0;

　　　　}

　　第一步：gcc -o test test.c

　　第二步： valgrind --tool=memcheck --leak-check=yes ./test

　　结果:

==3053== Memcheck, a memory error detector
==3053== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==3053== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==3053== Command: ./a.out
==3053==
==3053==
==3053== HEAP SUMMARY:
==3053== in use at exit: 400 bytes in 1 blocks
==3053== total heap usage: 1 allocs, 0 frees, 400 bytes allocated
==3053==
==3053== 400 bytes in 1 blocks are definitely lost in loss record 1 of 1
==3053== at 0x402B454: operator new[](unsigned int) (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==3053== by 0x8048528: main (temp.cc:41)
==3053==
==3053== LEAK SUMMARY:
==3053== definitely lost: 400 bytes in 1 blocks
==3053== indirectly lost: 0 bytes in 0 blocks
==3053== possibly lost: 0 bytes in 0 blocks
==3053== still reachable: 0 bytes in 0 blocks
==3053== suppressed: 0 bytes in 0 blocks
==3053==
==3053== For counts of detected and suppressed errors, rerun with: -v
==3053== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

分析：

　　上面的==3053==,3053代表test的进程号

　　从上面可看到 ，by 0x8048528:main(temp.cc:41)第41行用operator new分配了400字节内存但是没有释放，最后总结此进程泄露内存400字节

3.将内存检测工具与gdb一起使用

　　命令: valgrind --tool=memcheck --leak-check=yes --db-attach=yes ./test

　　--db-attach默认调试器是GDB，可以使用--db-attach=<command>指定