Convert calendar time to local time
#include <time.h> struct tm* localtime_r( const time_t* timer, struct tm* result );
- A pointer to a time_t object that contains the calendar time that you want to convert.
- A pointer to a tm structure where the function can store the converted time.
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The localtime_r() function converts the calendar time pointed to by timer into local time, storing the information in the struct tm that result points to. Whenever you call localtime_r(), it calls tzset() .
You typically get a calendar time by calling time() . That time is Coordinated Universal Time (UTC, formerly known as Greenwich Mean Time or GMT).
You typically use the date command to set the computer's internal clock using Coordinated Universal Time (UTC). Use the TZ environment variable or _CS_TIMEZONE configuration string to establish the local time zone.
A pointer to result, the struct tm .