HP C/iX Library Reference Manual (30026-90004)

234 Chapter5

HP C/iX Library Function Descriptions

localtime

Converts time to the local time zone.

Syntax

#include <time.h>

struct tm *localtime (const time_t *

timer

);

Parameters

timer

A pointer to a variable of type time_t.

Return Values

x A pointer to a structured time variable of type tm.

Description

The localtime function is passed a pointer to a time_t variable whose value is typically

set by the time function. The localtime function converts this value into the structured

tm format expressed in local time, corrected for daylight saving time if applicable, and

returns a pointer to the structure.

By default, localtime() adjusts the return value to Eastern Standard Time (EST). You

may control this by using the MPE/iX command SETVAR TZ

name

. Time zone names, and

the format of TZTAB.LIB.SYS ﬁle containing offsets from UTC (Coordinated Universal

Time) are listed in appendix A, "Time Zones."

Example

The following code fragment assigns values to the tm structure members for the local time

zone:

#include <time.h>

…

struct tm *ptr, *localtime();

int time(), nseconds;

…

nseconds = time(NULL);

Once this code is executed, you can use ptr to access the different components of the local

time. For example, ptr -> tm_mon references the month of the year, and ptr -> tm_wday

references the day of the week.