gmtime_s.c File Reference

#include "safe_lib.h"

Include dependency graph for gmtime_s.c:

Macros
#define	_GNU_SOURCE

Functions
EXPORT struct tm *	gmtime_s (const time_t *restrict timer, struct tm *restrict dest)
	The gmtime_s function converts the given time since epoch to a calendar time, expressed in Coordinated Universal Time (UTC) in the struct tm format. More...

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

Function Documentation

gmtime_s()

EXPORT struct tm* gmtime_s	(	const time_t *restrict	timer,
		struct tm *restrict	dest
	)

The gmtime_s function converts the given time since epoch to a calendar time, expressed in Coordinated Universal Time (UTC) in the struct tm format.

The result is copied into the user-provided tm struct.

Remarks

SPECIFIED IN

• C11 standard (ISO/IEC 9899:2011): K.3.8.2.3 The gmtime_s function (p: 626-627) http://en.cppreference.com/w/c/chrono/gmtime
• ISO/IEC TR 24731, Programming languages, environments and system software interfaces, Extensions to the C Library, Part I: Bounds-checking interfaces

Parameters

[in]	timer	pointer to a epoch (long, seconds since 1970)
[out]	dest	pointer to a user-provided struct tm.

Precondition

timer and dest shall not be a null pointer.

Returns

copy of the dest pointer, or null pointer on error (which may be a runtime constraint violation or a failure to convert the specified time to UTC). May set errno to EOVERFLOW when *timer > 313360441200L, the year 10000, resp. LONG_MAX on 32bit systems or < 0, or to ESNULLP when dest or timer is a NULL pointer.

Note

gmtime returns a pointer to static data and is not thread-safe. When gmtime_r is available it used instead.

POSIX requires that this function sets errno to EOVERFLOW if it fails because the argument is too large. POSIX defines a thread-safe alternative gmtime_r, which is similar to the C11 function gmtime_s, except that it does not check the validity of its input parameters.

This function is available under windows with a different API, reversed argument order, and is not available with safeclib.

See also

localtime_s(), ctime_s()