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PSELECT(3)               BSD Library Functions Manual               PSELECT(3)

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

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

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

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 errorfds arguments are all identical to the analo-gous analogous
     gous 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, sigmask 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.

IMPLEMENTATION NOTES
     The pselect() function is implemented in the C library as a wrapper
     around select().

RETURN VALUES
     The pselect() function returns the same values and under the same condi-tions conditions
     tions 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)

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

BSD                              June 16, 2002                             BSD