Biblioteca padrão C <time.h>

time.h O cabeçalho define quatro tipos de variáveis, duas macros e várias funções de operações de data e hora.

Variáveis da biblioteca

A seguir estão os tipos de variáveis definidos no cabeçalho time.h:

Number	Variável & Descrição
1	size_t É um tipo de inteiro sem sinal, é sizeof O resultado da palavra-chave.
2	clock_t Este é um tipo adequado para armazenar tempo de processador.
3	time_t is This is suitable for storing calendar time types.
4	struct tm This is a structure used to save time and date.

The definition of the tm structure is as follows:

struct tm {
　　　int tm_sec;　　　　　　　　　/*　Second, ranging from 0 to　59　　　　　　　　*/
　　　int tm_min;　　　　　　　　　/*　Minute, ranging from 0 to　59　　　　　　　　*/
　　　int tm_hour;　　　　　　　　/*　Hour, ranging from 0 to　23　　　　　　　　*/
　　　int tm_mday;　　　　　　　　/*　Day of the month, ranging from　1　to　31　　　　*/
　　　int tm_mon;　　　　　　　　　/*　Month, ranging from 0 to　11　　　　　　　　*/
　　　int tm_year;　　　　　　　　/*　Since　19Years since 00　　　　　　　　*/
　　　int tm_wday;　　　　　　　　/*　Day of the week, ranging from 0 to　6　　　　*/
　　　int tm_yday;　　　　　　　　/*　Day of the year, ranging from 0 to　365　　　　*/
　　　int tm_isdst;　　　　　　　/*　Daylight Saving Time　　　　　　　　　　　　　　　　*/
};

Library Macro

The following are the macros defined in the header file time.h:

Number	Macro & Description
1	NULL This macro is the value of a null pointer constant.
2	CLOCKS_PER_SEC This macro represents the number of processor clock cycles per second.

Library Function

The following are the functions defined in the header file time.h:

Number	Function & Description
1	char *asctime(const struct tm *timeptr) Returns a pointer to a string that represents the date and time of the structure timeptr.
2	clock_t clock(void) Returns the time used by the processor clock since the start of program execution (usually at the beginning of the program).
3	char *ctime(const time_t *timer) Returns a string representing the local time, based on the parameter timer.
4	double difftime(time_t time12, time_t time )1 Returns time2 and time1-The difference in seconds between (time2time
5	struct tm *)。 *timer) The value of the timer is decomposed into a tm structure and represented in Coordinated Universal Time (UTC), also known as Greenwich Mean Time (GMT).
6	struct tm *localtime(const time_t *timer) The value of the timer is decomposed into a tm structure and represented in the local time zone.
7	time_t mktime(struct tm *timeptr) Convert the structure pointed to by timeptr to a time_t value based on the local time zone.
8	size_t strftime(char *str, size_t maxsize, const char *format, const struct tm *timeptr) Formatar a estrutura de tempo representada pelo timeptr com base nas regras de formatação definidas no format, e armazená-la em str.
9	time_t time(time_t *timer) Calcular a data do calendário atual e codificá-la no formato time_t.