Head First C学习之安装valgrind和使用

Head Frist C:302页中用到了Valgrind工具，

关于valgrind

valgrind是一个通过伪造malloc()可以监控分配在堆的数据。
当程序想分配堆上的存储器时，valgrind将会拦截你对malloc()和free()的调用，然后允许自己的malloc()和free(),valgrind的malloc()会记录调用他的是那一段代码，和分配了那一段存储器。
程序结束时，valgrind回汇报堆上有哪些数据，并告诉你这些数据是哪段代码创建的。

安装valgrind

#curl -O http://valgrind.org/downloads/valgrind-3.11.0.tar.bz2
#tar -xjvf valgrind-3.11.0.tar.bz2
cd valgrind-3.11.0
#./configure
#make
#sudo make install

但是在make的过程中出现如下错误

#make[2]: *** No rule to make target `/usr/include/mach/mach_vm.defs', needed by `m_mach/mach_vmUser.c'.  Stop.
#make[1]: *** [install-recursive] Error 1
#make: *** [install] Error 2

需要安装命令行工具脚本如下

#xcode-select --install

因为Mac是64位，所以需要将./configure改成如下脚本

#./configure --disable-tls --enable-only64bit --build=amd64-darwin
#make
#sudo make install

使用valgrind

调试代码（可疑人物识别专家系统（SPIES））：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct node{
    char *question;
    struct node *no;
    struct node *yes;
}node;

int yes_no(char *question)
{
    char answer[3];
    printf("%s?(y/n):",question);
    fgets(answer,3,stdin);
    return answer[0] == 'y';
}

node * create(char *question)
{
    node *n = malloc(sizeof(node));
    n->question = strdup(question);
    n->no = NULL;
    n->yes= NULL;
    return n;
}

void release(node *n)
{
    if (n){
        if(n->no)
            release(n->no);
        if(n->yes)
            release(n->yes);
        if(n->question)
            free(n->question);
        free(n);
    }
}

int main()
{
    char question[80];
    char suspect[20];//犯罪嫌疑人
    node *start_node = create("Does suspect have a mustache");
    start_node->no = create("Loretta Barnsworth");
    start_node->yes = create("Vinny the Spoon");
    node * current;
    do{
        current = start_node;
        while(1){
            if(yes_no(current->question)){
                if(current->yes){
                    current = current->yes;
                }else{
                    printf("SUSPECT IDENTIFIED\n");
                    break;
                }
            }else if(current->no){
                current = current->no;
            }else{
                //
                printf("Who 's the suspect?\n ");
                fgets(suspect,20,stdin);
                node *yes_node = create(suspect);
                current->yes = yes_node;
                //
                node *no_node = create(current->question);
                current->no = no_node;
                //
                printf("Give me a question that is True for  %s but not %s? ",suspect,current->question);
                fgets(question,80,stdin);
                current->question = strdup(question);
                break;
            }
        }
    }while(yes_no("Run again"));
    release(start_node);
    return 0;
}

使用valgrind运行代码欠，余姚添加调试信息,-g;

#gcc -g spies.c -o spies
#valgrind --leak-check=full ./spies

valgrind参考资料：
Mac下valgrind的安装和使用
Unix下C程序内存泄漏检测工具Valgrind安装与使用