POSIX_C_LANG_SUPPORT_R

POSIX C Language Support (reentrant) option group. More...

Functions
int	rand_r (unsigned int *seed)
	Generate a pseudo-random number (reentrant).
void	qsort_r (void *base, size_t nmemb, size_t size, int(*compar)(const void *a, const void *b, void *arg), void *arg)
	Sort an array with a comparison function that takes a context argument.
char *	strtok_r (char *str, const char *sep, char **state)
	Tokenize a string into tokens (reentrant).
char *	asctime_r (const struct tm *ZRESTRICT tm, char *ZRESTRICT buf)
	Convert broken-down time to a string (thread-safe version of asctime()).
char *	ctime_r (const time_t *clock, char *buf)
	Convert a time_t to a string (thread-safe version of ctime()).
struct tm *	gmtime_r (const time_t *ZRESTRICT timer, struct tm *ZRESTRICT result)
	Convert a time_t to UTC broken-down time (thread-safe version of gmtime()).
struct tm *	localtime_r (const time_t *ZRESTRICT timer, struct tm *ZRESTRICT result)
	Convert a time_t to local broken-down time (thread-safe version of localtime()).

Detailed Description

POSIX C Language Support (reentrant) option group.

Function Documentation

asctime_r()

char * asctime_r	(	const struct tm *ZRESTRICT	tm,
		char *ZRESTRICT	buf
	)

Convert broken-down time to a string (thread-safe version of asctime()).

Parameters

tm	Broken-down time.
buf	Caller-supplied buffer of at least 26 bytes.

Returns

buf on success, or NULL on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/asctime_r.html

ctime_r()

char * ctime_r	(	const time_t *	clock,
		char *	buf
	)

Convert a time_t to a string (thread-safe version of ctime()).

Parameters

clock	Pointer to a time_t value.
buf	Caller-supplied buffer of at least 26 bytes.

Returns

buf on success, or NULL on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctime_r.html

gmtime_r()

struct tm * gmtime_r	(	const time_t *ZRESTRICT	timer,
		struct tm *ZRESTRICT	result
	)

Convert a time_t to UTC broken-down time (thread-safe version of gmtime()).

Parameters

timer	Pointer to the time_t value.
result	Caller-supplied storage for the result.

Returns

result on success, or NULL on failure.

localtime_r()

struct tm * localtime_r	(	const time_t *ZRESTRICT	timer,
		struct tm *ZRESTRICT	result
	)

Convert a time_t to local broken-down time (thread-safe version of localtime()).

Parameters

timer	Pointer to the time_t value.
result	Caller-supplied storage for the result.

Returns

result on success, or NULL on failure.

qsort_r()

void qsort_r	(	void *	base,
		size_t	nmemb,
		size_t	size,
		int(*)(const void *a, const void *b, void *arg)	compar,
		void *	arg
	)

Sort an array with a comparison function that takes a context argument.

Parameters

base	Pointer to the start of the array.
nmemb	Number of elements in the array.
size	Size of each element in bytes.
compar	Comparison function; receives a caller-supplied arg.
arg	Context pointer passed to compar.

See also

https://pubs.opengroup.org/onlinepubs/9799922210/functions/qsort_r.html

rand_r()

int rand_r

(

unsigned int *

seed

)

Generate a pseudo-random number (reentrant).

Updates seed and returns the next value in the same sequence as rand() after srand(seed).

Parameters

seed	Pointer to the seed value; updated on return.

Returns

A pseudo-random integer in the range [0, RAND_MAX].

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/rand_r.html

strtok_r()

char * strtok_r	(	char *	str,
		const char *	sep,
		char **	state
	)

Tokenize a string into tokens (reentrant).

Parameters

str	First call passes the string; subsequent calls pass NULL.
sep	Delimiter characters.
state	Caller-provided state for reentrant tokenization.

Returns

Pointer to the next token, or NULL when no more tokens remain.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtok_r.html