allow signals to interrupt system calls
() function is used to change the
system call restart behavior when a system call is interrupted by the
specified signal. If flag
is false (0),
system calls will be restarted if they are interrupted by the specified signal
and no data has been transferred yet.
System call restart is the default behavior on
is true (1), the 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 the global
. 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
systems prior to 4.2BSD
well as most systems based upon AT&T System V
Programs may switch between restartable and interruptible system call operation
as often as desired in the execution of a program. Issuing a
() call during the execution of a
signal handler will cause the new action to take place on the next signal to
() returns 0 on success or -1 if an
invalid signal number has been specified.
() function appeared in