_POSIX_THREAD_SAFE_FUNCTIONS

POSIX Thread-Safe Functions option. More...

Files
file	grp.h
	POSIX group database access (<grp.h>)
file	pwd.h
	POSIX password database access (<pwd.h>)

Functions
int	getgrnam_r (const char *name, struct group *grp, char *buffer, size_t bufsize, struct group **result)
	Look up a group entry by name (thread-safe).
int	getgrgid_r (gid_t gid, struct group *grp, char *buffer, size_t bufsize, struct group **result)
	Look up a group entry by group ID (thread-safe).
int	getenv_r (const char *name, char *buf, size_t len)
	Get an environment variable into a caller-supplied buffer (BSD extension).
int	getpwnam_r (const char *nam, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result)
	Look up a password entry by name (thread-safe).
int	getpwuid_r (uid_t uid, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result)
	Look up a password entry by user ID (thread-safe).
int	getlogin_r (char *name, size_t namesize)
	Get the login name of the user into a caller-supplied buffer.
int	ttyname_r (int fildes, char *name, size_t namesize)
	Get the name of the terminal into a caller-supplied buffer.

Detailed Description

POSIX Thread-Safe Functions option.

Covers getlogin_r(), ttyname_r(), strerror_r(), and other _r()-suffixed thread-safe function variants.

Function Documentation

getenv_r()

int getenv_r	(	const char *	name,
		char *	buf,
		size_t	len
	)

Get an environment variable into a caller-supplied buffer (BSD extension).

Thread-safe alternative to getenv().

Parameters

name	Name of the environment variable.
buf	Buffer to write the value into.
len	Size of buf.

Returns

0 on success, or a positive error number on failure (ENOENT if not set, ERANGE if buf is too small).

See also

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

getgrgid_r()

int getgrgid_r	(	gid_t	gid,
		struct group *	grp,
		char *	buffer,
		size_t	bufsize,
		struct group **	result
	)

Look up a group entry by group ID (thread-safe).

Parameters

gid	Numerical group ID to search for.
grp	Caller-supplied structure to fill in.
buffer	Caller-supplied buffer for string fields.
bufsize	Size of buffer.
result	Output: pointer to grp on success, or NULL if not found.

Returns

0 on success, or a positive error number on failure.

See also

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

getgrnam_r()

int getgrnam_r	(	const char *	name,
		struct group *	grp,
		char *	buffer,
		size_t	bufsize,
		struct group **	result
	)

Look up a group entry by name (thread-safe).

Parameters

name	Group name to search for.
grp	Caller-supplied structure to fill in.
buffer	Caller-supplied buffer for string fields.
bufsize	Size of buffer.
result	Output: pointer to grp on success, or NULL if not found.

Returns

0 on success, or a positive error number on failure.

See also

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

getlogin_r()

int getlogin_r	(	char *	name,
		size_t	namesize
	)

Get the login name of the user into a caller-supplied buffer.

See also

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

getpwnam_r()

int getpwnam_r	(	const char *	nam,
		struct passwd *	pwd,
		char *	buffer,
		size_t	bufsize,
		struct passwd **	result
	)

Look up a password entry by name (thread-safe).

Parameters

nam	User login name to search for.
pwd	Caller-supplied structure to fill in.
buffer	Caller-supplied buffer for string fields.
bufsize	Size of buffer.
result	Output: pointer to pwd on success, or NULL if not found.

Returns

0 on success, or a positive error number on failure.

See also

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

getpwuid_r()

int getpwuid_r	(	uid_t	uid,
		struct passwd *	pwd,
		char *	buffer,
		size_t	bufsize,
		struct passwd **	result
	)

Look up a password entry by user ID (thread-safe).

Parameters

uid	Numerical user ID to search for.
pwd	Caller-supplied structure to fill in.
buffer	Caller-supplied buffer for string fields.
bufsize	Size of buffer.
result	Output: pointer to pwd on success, or NULL if not found.

Returns

0 on success, or a positive error number on failure.

See also

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

ttyname_r()

int ttyname_r	(	int	fildes,
		char *	name,
		size_t	namesize
	)

Get the name of the terminal into a caller-supplied buffer.

See also

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