【阅读笔记】《C程序员 从校园到职场》第七章 指针和结构体

/**********************************************************************
*版权所有 (C)2014, Zhou Zhaoxiong。
*文件名称： Pointer.c
*内容摘要：用于演示指针和结构体操作
**********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h> 

//字段最大长度
#define MAX_RET_BUF_LEN     (1024) 

//数据类型
typedef unsigned char       UINT8;
typedef unsigned short int  UINT16;
typedef unsigned int        UINT32;
typedef signed   int        INT32;
typedef unsigned char       BOOL;


//参数类型
#define MML_INT8_TYPE       0
#define MML_INT16_TYPE      1
#define MML_INT32_TYPE      2
#define MML_STR_TYPE        3
#define  TRUE         (BOOL)1
#define  FALSE        (BOOL)0 

//员工信息结构体
typedef struct
{
    UINT8  szEmployeeID[1024];      //员工工号
    UINT8  szEmployeeName[1024];    //员工姓名
    UINT32 iEmployeeAge;            //员工年龄
} T_EmployeeInfo; 

/**********************************************************************
*功能描述：获取字符串中某一个字段的数据
*输入参数：    iSerialNum-字段编号(为正整数)
             iContentType-需要获取的内容的类型
             pSourceStr-源字符串
             pDstStr-目的字符串(提取的数据的存放位置)
             cIsolater-源字符串中字段的分隔符
             iDstStrSize-目的字符串的长度
*输出参数：无
*返回值： TRUE-成功  FALSE-失败
*其它说明：无
***********************************************************************/
BOOL GetValueFromStr(UINT16 iSerialNum, UINT8 iContentType, UINT8 *pSourceStr, UINT8 *pDstStr, UINT8 cIsolater, UINT32 iDstStrSize)
{
    UINT8  *pStrBegin                 = NULL;
    UINT8  *pStrEnd                   = NULL;
    UINT8   szRetBuf[MAX_RET_BUF_LEN] = {0}; //截取出的字符串放入该数组中
    UINT8  *pUINT8                    = NULL;
    UINT16 *pUINT16                   = NULL;
    UINT32 *pUINT32                   = NULL;
    UINT32  iFieldLen                 = 0;     //用于表示每个字段的实际长度 

    if (pSourceStr == NULL)           //对输入指针的异常情况进行判断
    {
        return FALSE;
    }
    //字段首
    pStrBegin = pSourceStr;
    while (--iSerialNum != 0)
    {
        pStrBegin = strchr(pStrBegin, cIsolater);
        if (pStrBegin == NULL)
        {
            return FALSE;
        }
        pStrBegin ++;
    }

    //字段尾
    pStrEnd = strchr(pStrBegin, cIsolater);
    if (pStrEnd == NULL)
    {
        return FALSE;
    } 

    iFieldLen = (UINT16)(pStrEnd - pStrBegin);
    if(iFieldLen >= MAX_RET_BUF_LEN) //进行异常保护, 防止每个字段的值过长
    {
        iFieldLen = MAX_RET_BUF_LEN - 1;
    } 

    memcpy(szRetBuf, pStrBegin, iFieldLen);
    //将需要的字段值放到pDstStr中去
    switch (iContentType)
    {
        case MML_STR_TYPE:                        //字符串类型
        {
            strncpy(pDstStr, szRetBuf, iDstStrSize);
            break;
        }
        case MML_INT8_TYPE:                       //字符类型
        {
            pUINT8   = (UINT8 *)pDstStr;
            *pDstStr = (UINT8)atoi(szRetBuf);
            break;
        }

        case MML_INT16_TYPE:                      // short int类型
        {
            pUINT16  = (UINT16 *)pDstStr;
            *pUINT16 = (UINT16)atoi(szRetBuf);
            break;
        }

         case MML_INT32_TYPE:                      // int类型
        {
            pUINT32  = (UINT32 *)pDstStr;
            *pUINT32 = (UINT32)atoi(szRetBuf);
            break;
        }

        default:                                  //一定要有default分支
        {
            return FALSE;
        }
    }

    return TRUE;
}
 

 /****************************************************************
*功能描述:  主函数                                             *
*输入参数:  无                                                 *
*输出参数:  无                                                 *
*返回值  ：无                                                 
****************************************************************/

INT32 main(void)
{
    UINT32  iInfoCount          = 0;      //该变量用于计算记录条数
    UINT8   szContentLine[1024] = {0};       //用于存放从文件中独到的每条记录
    FILE   *hFile               = NULL;   //文件句柄指针   
    //打开文件
    hFile = fopen("EmployeeInfo.ini", "r");
    if (!hFile)                     //打开失败
    {
        printf("Open EmployeeInfo.ini failed!\n");
        return -1;                  //异常退出
    } 

    while (NULL != fgets(szContentLine, sizeof(szContentLine), hFile))
    {
        T_EmployeeInfo t_EmployeeInfo = {0};
        iInfoCount ++;           //每读取到一条记录, 则记录条数加1

        //获取EmployeeID
        if (TRUE != GetValueFromStr(1, MML_STR_TYPE, szContentLine, t_EmployeeInfo.szEmployeeID, ‘|‘, sizeof(t_EmployeeInfo.szEmployeeID)))
        {
            printf("获取第%d位员工的工号失败.\n", iInfoCount);
            return -1;
        }

        //获取EmployeeName
        if (TRUE != GetValueFromStr(2, MML_STR_TYPE, szContentLine, t_EmployeeInfo.szEmployeeName, ‘|‘, sizeof(t_EmployeeInfo.szEmployeeName)))
        {
            printf("获取第%d位员工的姓名失败.\n", iInfoCount);
            return -1;
        }

         //获取EmployeeAge
        if (TRUE != GetValueFromStr(3, MML_INT32_TYPE, szContentLine, (UINT8 *)&(t_EmployeeInfo.iEmployeeAge), ‘|‘, sizeof(t_EmployeeInfo.iEmployeeAge)))
        {
            printf("获取第%d位员工的年龄失败.\n", iInfoCount);
            return -1;
        }

        //逐条打印每个员工的信息
        printf("第%d位员工的信息为:工号=%s, 姓名=%s,年龄=%d.\n", iInfoCount, t_EmployeeInfo.szEmployeeID, t_EmployeeInfo.szEmployeeName, t_EmployeeInfo.iEmployeeAge);
    }

    fclose(hFile);         //最后一定要关闭文件句柄
    return 0;
}

typedef struct
{
    UINT8  szEmployeeID[1024];       //员工工号
    UINT8  szEmployeeName[1024];    //员工姓名
    UINT32 iEmployeeAge;            //员工年龄
} T_EmployeeInfo;

if (TRUE != GetValueFromStr(3, MML_INT32_TYPE, szContentLine, (UINT8 *)&(t_EmployeeInfo.iEmployeeAge), ‘|‘, sizeof(t_EmployeeInfo.iEmployeeAge)))
{
    printf("获取第%d位员工的年龄失败.\n", iInfoCount);
    return -1;
}