关于 c:tm struct time.h 未规范化


tm struct time.h not normalizing

我正在向我的 tm 结构的时间(小时、分钟、秒)成员添加值，即使我正在使用 mktime()，它们也没有更新/规范化这是代码：

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struct tm timeStruct;
char buffer[80];

timeStruct.tm_year = 2016 - 1900;
timeStruct.tm_mon = 3;
timeStruct.tm_mday = 32;
timeStruct.tm_hour = 23;
timeStruct.tm_min = 59;
timeStruct.tm_sec = 59;
timeStruct.tm_isdst = -1;

printf("Date before adding interval: \
");
mktime(&timeStruct);
strftime(buffer, sizeof(buffer),"%c", &timeStruct);
printf(buffer);

printf("\
the year is %d\
", timeStruct.tm_year );
printf("the month is %d\
", timeStruct.tm_mon );
printf("the day is %d\
", timeStruct.tm_mday );
printf("the hours are %d\
", timeStruct.tm_hour );
printf("the minutes are %d\
", timeStruct.tm_min );
printf("the seconds are %d\
", timeStruct.tm_sec );

/*
 * Add intervals to time
 */
timeStruct.tm_sec += 2;
timeStruct.tm_min += 2;
timeStruct.tm_hour += 5;

printf("Date after adding interval: \
");
strftime(buffer, sizeof(buffer),"%c", &timeStruct);
printf(buffer);

printf("\
the year is %d\
", timeStruct.tm_year );
printf("the month is %d\
", timeStruct.tm_mon );
printf("the day is %d\
", timeStruct.tm_mday );
printf("the hours are %d\
", timeStruct.tm_hour );
printf("the minutes are %d\
", timeStruct.tm_min );
printf("the seconds are %d\
", timeStruct.tm_sec );

控制台输出：1

这是控制台输出的打印输出：

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Date before adding interval:
Mon May  2 23:59:59 2016
the year is 116
the month is 4
the day is 2
the hours are 23
the minutes are 59
the seconds are 59
Date after adding interval:
Mon May  2 28:61:61 2016
the year is 116
the month is 4
the day is 2
the hours are 28
the minutes are 61
the seconds are 61

我在 Windows 7 机器上使用 Eclipse，用 Cygwin 编译。

相关讨论

在您的代码中，仅在添加间隔之前调用 mktime()。您需要在添加间隔后调用它(以便它可以标准化更新的 timeStruct)：

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printf("Date after adding interval: \
");
mktime(&timeStruct);    // <--- here
strftime(buffer, sizeof(buffer),"%c", &timeStruct);

输出：

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Tue May  3 05:02:01 2016
the year is 116
the month is 4
the day is 3
the hours are 5
the minutes are 2
the seconds are 1

这里是更正后的代码：

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#include <stdio.h>
#include <time.h>

struct tm timeStruct;
char buffer[80];

int main( void )
{
    timeStruct.tm_year = 2016 - 1900;
    timeStruct.tm_mon = 3;
    timeStruct.tm_mday = 32;
    timeStruct.tm_hour = 23;
    timeStruct.tm_min = 59;
    timeStruct.tm_sec = 59;
    timeStruct.tm_isdst = -1;

    printf("Date before adding interval: \
");
    if( (time_t)-1 == mktime(&timeStruct) )
    {
        perror("first call to mktime failed due to:");
    }

    if( 0 == strftime(buffer, sizeof(buffer),"%c", &timeStruct) )
    {
        perror("first call to strftime failed due to:");
    }

    printf("\
\
%s\
", buffer);

    printf("\
the year is %d\
", timeStruct.tm_year );
    printf("the month is %d\
", timeStruct.tm_mon );
    printf("the day is %d\
", timeStruct.tm_mday );
    printf("the hours are %d\
", timeStruct.tm_hour );
    printf("the minutes are %d\
", timeStruct.tm_min );
    printf("the seconds are %d\
", timeStruct.tm_sec );

    /*
     * Add intervals to time
     */
    timeStruct.tm_sec += 2;
    timeStruct.tm_min += 2;
    timeStruct.tm_hour += 5;
    timeStruct.tm_year = 2016 - 1900;
    timeStruct.tm_mon = 3;
    timeStruct.tm_mday = 32;
    timeStruct.tm_hour = 23;
    timeStruct.tm_min = 59;
    timeStruct.tm_sec = 59;
    timeStruct.tm_isdst = -1;

    printf("Date after adding first interval: \
");
    if( (time_t)-1 == mktime(&timeStruct) )
    {
        perror("second call to mktime failed due to:");
    }

    if( 0 == strftime(buffer, sizeof(buffer),"%c", &timeStruct) )
    {
        perror("second call to strftime failed due to:");
    }

    printf("\
\
%s\
", buffer);

    printf("\
the year is %d\
", timeStruct.tm_year );
    printf("the month is %d\
", timeStruct.tm_mon );
    printf("the day is %d\
", timeStruct.tm_mday );
    printf("the hours are %d\
", timeStruct.tm_hour );
    printf("the minutes are %d\
", timeStruct.tm_min );
    printf("the seconds are %d\
", timeStruct.tm_sec );

    /*
     * Add intervals to time
     */
    timeStruct.tm_sec += 2;
    timeStruct.tm_min += 2;
    timeStruct.tm_hour += 5;

    printf("Date after adding second interval: \
");
    if( (time_t)-1 == mktime(&timeStruct) )
    {
        perror("third call to mktime failed due to:");
    }

    if( 0 == strftime(buffer, sizeof(buffer),"%c", &timeStruct) )
    {
        perror("third call to strftime failed due to:");
    }

    printf("\
\
%s\
", buffer);

    printf("\
the year is %d\
", timeStruct.tm_year );
    printf("the month is %d\
", timeStruct.tm_mon );
    printf("the day is %d\
", timeStruct.tm_mday );
    printf("the hours are %d\
", timeStruct.tm_hour );
    printf("the minutes are %d\
", timeStruct.tm_min );
    printf("the seconds are %d\
", timeStruct.tm_sec );
}

这是当前/更正后的代码输出：

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Date before adding interval:


Mon May  2 23:59:59 2016

the year is 116
the month is 4
the day is 2
the hours are 23
the minutes are 59
the seconds are 59
Date after adding first interval:


Mon May  2 23:59:59 2016

the year is 116
the month is 4
the day is 2
the hours are 23
the minutes are 59
the seconds are 59
Date after adding second interval:


Tue May  3 05:02:01 2016

the year is 116
the month is 4
the day is 3
the hours are 5
the minutes are 2
the seconds are 1