C语言月份字符转月份数值实现

这里直接利用的宏就可以实现，月份字符串转月份数值功能，例如将“jan” 转为数字1，即1月份。

datetime.h

#ifndef __DATETIME_H_
#define __DATETIME_H_

#include <rtthread.h>


#define MONTH_TABLE() \
    DEF_MONTH(Jan) \
    DEF_MONTH(Feb) \
    DEF_MONTH(Mar) \
    DEF_MONTH(Apr) \
    DEF_MONTH(May) \
    DEF_MONTH(Jun) \
    DEF_MONTH(Jul) \
    DEF_MONTH(Aug) \
    DEF_MONTH(Oct) \
    DEF_MONTH(Nov) \
    DEF_MONTH(Dec) 


//定义月份枚举，其枚举元素名和月份缩略字符串同名
typedef enum 
{
    E_MONTH_START = 0,
#define DEF_MONTH(v) v,
    MONTH_TABLE()     
#undef DEF_MONTH
    E_MONTH_END,
}E_MONTH;

//这里实现了几个实用的函数
uint32_t datetimeToUtc(const char* date, const char*time);
void datetimeFormat(const char* date, char*out);
uint32_t versionStrToInt(const char* version);

#endif

datetime.c

#include "datetime.h"
#include <stdio.h>
 #include <string.h>
#include <time.h>
#include "log.h"


//巧用'#'符，直接将枚举转为对应字符串
const char* MonthStringOf(E_MONTH c) {
    switch (c) {
#define DEF_MONTH(v) \
        case v: \
            return #v;
        MONTH_TABLE()
#undef DEF_MONTH
      default:
        return "Unknown";
    }
}

//同理，这里使用'#'符，将枚举转化为字符串后，在和输入参数比较，相等则返回该月份缩略字符串代表的月份数值
int getMonthNumber(const char* month) {
#define DEF_MONTH(v) \
        if(0 == rt_strcmp(#v, month)) return v;
        MONTH_TABLE()
#undef DEF_MONTH
}

void mySplit(const char *src, const char *separator, char dest[][20], int *num)
{
    char *pPre = NULL;
    char *pNext = NULL;

     //记录分隔符数量
     int count = 0;
     //原字符串为空
     if (src == NULL || strlen(src) == 0)
        return;
    //未输入分隔符
     if (separator == NULL || strlen(separator) == 0)
        return;

     //获得第一个由分隔符分割的字符串
    pNext = strtok(src,separator);
    while(pNext != NULL) {
        //存入到目的字符串数组中
        pPre = pNext;
        pNext = strtok(NULL, separator);

        if (pPre && pNext)
        {
            strncpy(dest[count++], pPre, (pNext-pPre-1));
        }
        else if(pPre)
        {
            strcpy(dest[count++], pPre);
        }
    }

    *num = count;
}

//时间字符串转UTC秒数
//date输入格式：Aug 15 2023, time输入格式：11:08:22
uint32_t datetimeToUtc(const char* date, const char*time)
{
    char result[10][20];
    int num = 0;
    struct tm local_time;

    if (date == NULL || time == NULL) return 0;

    rt_memset(&local_time, 0, sizeof(local_time));
    rt_memset(result, 0, sizeof(result));

    mySplit(date, " ", result, &num);
    if (num < 3)
    {
        LOGT("","date:%s num < 3! num=%d\n",date, num);
        return 0;
    }
    else
    {
        local_time.tm_mon = getMonthNumber(result[0]) - 1;
        local_time.tm_mday = atoi(result[1]);
        local_time.tm_year = atoi(result[2]) - 1900;
    }

    rt_memset(result, 0, sizeof(result));
    num = 0;
    mySplit(time, ":", result, &num);
    if (num < 3)
    {
        LOGT("","time:%s num < 3! num=%d\n",time, num);
        return 0;
    }
    else
    {
        local_time.tm_hour = atoi(result[0]);
        local_time.tm_min = atoi(result[1]);
        local_time.tm_sec = atoi(result[2]);
    }

    time_t utc_time = mktime(&local_time);

    return utc_time;
}

//时间字符串格式化输出
//date输入格式：Aug 15 2023, 输出格式：230815
void datetimeFormat(const char* date, char* out)
{
    char result[10][20];
    int num = 0;

    if (date == NULL || time == NULL) return;

    rt_memset(result, 0, sizeof(result));

    mySplit(date, " ", result, &num);
    if (num < 3)
    {
        LOGT("","date:%s num < 3! num=%d\n",date, num);
        return;
    }
    else
    {
        rt_sprintf(out, "%2d%02d%02d", atoi(result[2])%100, getMonthNumber(result[0]), atoi(result[1]));
    }
}


//版本字符串转整数1.3.1 -> 10301 ,次版本号，修订版本号分别占两位数
uint32_t versionStrToInt(const char* version)
{
    char result[10][20];
    int num = 0;
    uint32_t i_vertion = 0;

    if (version == NULL) return 0;
    rt_memset(result, 0, sizeof(result));

    mySplit(version, ".", result, &num);
    if (num < 3)
    {
        LOGT("","version:%s num < 3! num=%d\n",num);
        return 0;
    }
    else
    {
        i_vertion = atoi(result[0])*10000;
        i_vertion += atoi(result[1])*100;
        i_vertion += atoi(result[2]);
    }

    return i_vertion;
}