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C library function - mktime()
Description
The C library function time_t mktime(struct tm *timeptr) converts the structure pointed to by timeptr into a time_t value according to the local time zone.
Declaration
Following is the declaration for mktime() function.
time_t mktime(struct tm *timeptr)
Parameters
timeptr − This is the pointer to a time_t value representing a calendar time, broken down into its components. Below is the detail of timeptr structure
struct tm { int tm_sec; /* seconds, range 0 to 59 */ int tm_min; /* minutes, range 0 to 59 */ int tm_hour; /* hours, range 0 to 23 */ int tm_mday; /* day of the month, range 1 to 31 */ int tm_mon; /* month, range 0 to 11 */ int tm_year; /* The number of years since 1900 */ int tm_wday; /* day of the week, range 0 to 6 */ int tm_yday; /* day in the year, range 0 to 365 */ int tm_isdst; /* daylight saving time */ };
Return Value
This function returns a time_t value corresponding to the calendar time passed as argument. On error, a -1 value is returned.
Example
The following example shows the usage of mktime() function.
#include#include int main () { int ret; struct tm info; char buffer[80]; info.tm_year = 2001 - 1900; info.tm_mon = 7 - 1; info.tm_mday = 4; info.tm_hour = 0; info.tm_min = 0; info.tm_sec = 1; info.tm_isdst = -1; ret = mktime(&info); if( ret == -1 ) { printf("Error: unable to make time using mktime\n"); } else { strftime(buffer, sizeof(buffer), "%c", &info ); printf(buffer); } return(0); }
Let us compile and run the above program that will produce the following result −
Wed Jul 4 00:00:01 2001
time_h.htm
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