SIGINTERRUPT(3) 					     Library Functions Manual						   SIGINTERRUPT(3)

NAME

       siginterrupt - allow signals to interrupt system calls

SYNOPSIS

       siginterrupt(sig, flag);
       int sig, flag;

DESCRIPTION

       Siginterrupt  is used to change the system call restart behavior when a system call is interrupted by the specified signal.  If the flag is
       false (0), then system calls will be restarted if they are interrupted by the specified signal and no data has been transferred yet.   Sys-
       tem call restart is the default behavior on 4.2 BSD.

       If  the flag is true (1), then restarting of system calls is disabled.  If a system call is interrupted by the specified signal and no data
       has been transferred, the system call will return -1 with errno set to EINTR.  Interrupted system calls that have started transferring data
       will  return the amount of data actually transferred.  System call interrupt is the signal behavior found on 4.1 BSD and AT&T System V UNIX
       systems.

       Note that the new 4.2 BSD signal handling semantics are not altered in  any  other  way.   Most	notably,  signal  handlers  always  remain
       installed  until  explicitly changed by a subsequent sigvec(2) call, and the signal mask operates as documented in sigvec(2).  Programs may
       switch between restartable and interruptible system call operation as often as desired in the execution of a program.

       Issuing a siginterrupt(3) call during the execution of a signal handler will cause the new action to take place on the next  signal  to	be
       caught.

NOTES

       This  library  routine uses an extension of the sigvec(2) system call that is not available in 4.2BSD, hence it should not be used if back-
       ward compatibility is needed.

RETURN VALUE

       A 0 value indicates that the call succeeded.  A -1 value indicates that an invalid signal number has been supplied.

SEE ALSO

       sigvec(2), sigblock(2), sigpause(2), sigsetmask(2).

4.3 Berkeley Distribution					   May 15, 1985 						   SIGINTERRUPT(3)