第 14 章 结构和其他数据形式（names3）

/*-----------------------------------
    names3.c -- 使用指针和 malloc()
-----------------------------------*/

#include <stdio.h>
#include <string.h>        //提供 strcpy()、strlen() 原型
#include <stdlib.h>        //提供 malloc()、free() 原型

#define SLEN 81

struct namect
{
    char *fname;        //fname、lname 分别保存内存分配的地址
    char *lname;
    int letters;
};

void getinfo(struct namect *);        //分配内存
void makeinfo(struct namect *);
void showinfo(const struct namect *);
void cleanup(struct namect *);
char* s_gets(char *st, int n);

int main()
{
    struct namect person;

    getinfo(&person);
    makeinfo(&person);
    showinfo(&person);
    cleanup(&person);

    return 0;
}

void getinfo(struct namect *pst)
{
    char temp[SLEN];

    printf("Please enter your first name.
");

    s_gets(temp, SLEN);
    pst->fname = (char*)malloc((strlen(temp) + 1) * sizeof(char));
    strcpy(pst->fname, temp);

    printf("Please enter your last name.
");

    s_gets(temp, SLEN);
    pst->lname = (char*)malloc((strlen(temp) + 1) * sizeof(char));
    strcpy(pst->lname, temp);
}

void makeinfo(struct namect *pst)
{
    pst->letters = strlen(pst->fname) + strlen(pst->lname);
}

void showinfo(const struct namect *pst)
{
    printf("%s %s, your name contains %d letters.
"
        , pst->fname, pst->lname, pst->letters);
}

void cleanup(struct namect *pst)
{
    free(pst->fname);
    free(pst->lname);
}

char* s_gets(char *st, int n)
{
    char *ret_val;
    char *find;

    if (ret_val = fgets(st, n, stdin))
    {
        if (find = strchr(st, '
'))
            *find = '';
        else
            while (getchar() != '
') continue;
    }

    return ret_val;
}