chap1 实验环境和示例源码

1. 建立32位可执行程序编译环境

$ sudo apt-get update

$ sudo apt-get install gcc-multilib

2. 示例源码1： bugging 程序( bugging.c )

这是一个简单的求和程序，计算 1+2+3+...+100 的值。程序存在bug，导致预期结果并不为5050

/* bugging.c */

#include 

int foo(int n)
{

    int sum;
    int i;

    for (i=0; i<=n; i++)
    {
        sum = sum+i;
    }

    return sum;
}

int main(int argc, char** argv)
{
    int result = 0;
    int N = 100;

    result = foo(N);

    printf("1+2+3+...+%d= %d\n", N, result);

    return 0;

}

3. 示例源码2：链表测试程序( linked_list.h、linked_list.c、test_linked_list.c )

本例的程序来源于 github, 程序定义了数据结构链表，并使用了三个测试函数进行测试

/* linked_list.h */

typedef struct node_t {
    char name[10];
    int id;
    char msg[30];
    struct node_t *next;
} node_t, *list_t;

/*
 * Modify h to point at NULL (empty list)
 */
void list_init(list_t *h);

int list_size(const list_t *h);

int list_empty(const list_t *h);

/*
 * prepend the node into the front
 */
void list_insert(list_t *h, node_t *n);

/*
 * delete first element in the lists, return the pointer to it
 */
node_t * list_delete(list_t *h, int id);


/*
 *
 */
void print_list(const list_t *h);

/* linked_list.c */

#include 
#include 
#include "linked_list.h"

void list_init(list_t *h) {
    *h = NULL;
}

int list_size(const list_t *h) {
    node_t *p = *h;
    int r = 0;
    do {
        r += 1;
        p = p->next;
    } while (p);
    return r;
}

int list_empty(const list_t *h) {
    return (*h == NULL);
}

void list_insert(list_t *h, node_t *n) {
    n->next = *h;
    *h = n;
}

node_t *list_find(const list_t *h, int id) {
    node_t *p = *h;
    while (p) {
        if (p->id == id) return p;
        p = p->next;
    }
}

node_t *list_find_before(const list_t *h, int id) {
    node_t *p = *h;
    while (p && p->next) {
        if (p->next->id == id) return p;
        p = p->next;
    }
    return NULL;
}

node_t *list_delete(list_t *h, int id) {
    node_t *r = NULL;
    if (*h && (*h)->id == id) {
        r = *h;
        *h = NULL;
        return r;
    }

    node_t *p = list_find_before(h, id);
    if (p) {
        r = p->next;
        p->next = p->next->next;
        r->next = NULL;
    }
    return r;
}

void print_list(const list_t *h) {
    node_t *p = *h;
    while (p) {
        printf("%d: %s says %s\n", p->id, p->name, p->msg);
        p = p->next;
    }
}

/* test_linked_list.c  */

#include 
#include "linked_list.h"
#include 
#include 
#include 


void test_delete_one() {
    list_t h;
    list_init(&h);
    node_t n;
    n.id = 0;
    strcpy(n.name, "hello");
    strcpy(n.msg, "world");
    list_insert(&h, &n);
    node_t *f = list_delete(&h, 0);
    assert(f == &n);
}


void test_delete() {
    list_t h;
    list_init(&h);
    node_t n[3];
    int i;
    for (i = 0; i < 3; i++) {
        n[i].id = i;
        list_insert(&h, &n[i]);
    }
    list_delete(&h, 1);
    assert(list_size(&h) == 2);
}

void core_dump_test() {
    int size = 0;
    list_t h;
    list_init(&h);
    size = list_size(&h);
    printf("list size is: %d\n", size);
}

int main () {
    test_delete();
    test_delete_one();
    core_dump_test();
    printf("Pass\n");
}