freebsd man page for pselect

PSELECT(2)						      BSD System Calls Manual							PSELECT(2)

NAME
     pselect -- synchronous I/O multiplexing a la POSIX.1g

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/select.h>

     int
     pselect(int nfds, fd_set * restrict readfds, fd_set * restrict writefds, fd_set * restrict exceptfds,
	 const struct timespec * restrict timeout, const sigset_t * restrict newsigmask);

DESCRIPTION
     The pselect() function was introduced by IEEE Std 1003.1g-2000 (``POSIX.1'') as a slightly stronger version of select(2).	The nfds, readfds,
     writefds, and exceptfds arguments are all identical to the analogous arguments of select().  The timeout argument in pselect() points to a
     const struct timespec rather than the (modifiable) struct timeval used by select(); as in select(), a null pointer may be passed to indicate
     that pselect() should wait indefinitely.  Finally, newsigmask specifies a signal mask which is set while waiting for input.  When pselect()
     returns, the original signal mask is restored.

     See select(2) for a more detailed discussion of the semantics of this interface, and for macros used to manipulate the fd_set data type.

RETURN VALUES
     The pselect() function returns the same values and under the same conditions as select().

ERRORS
     The pselect() function may fail for any of the reasons documented for select(2) and (if a signal mask is provided) sigprocmask(2).

SEE ALSO
     kqueue(2), poll(2), select(2), sigprocmask(2), sigsuspend(2)

STANDARDS
     The pselect() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').

HISTORY
     The pselect() function first appeared in FreeBSD 5.0.

AUTHORS
     The first implementation of pselect() function and this manual page were written by Garrett Wollman <wollman@FreeBSD.org>.

BSD
								  August 16, 2013							       BSD