sigaction.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 79 行

.\" SCCSID: @(#)sigaction.3	2.3	6/8/87
.TH sigaction 3 
.ie t .ds d \(dg
.el .ds d \z'|+'
.ie t .ds b \(bu
.el .ds b @
.SH Name
sigaction \- software signal facilities (POSIX)
.SH Syntax
.nf
.B #include <signal.h>
.PP
.B struct sigaction {
.B	void	 (*sa_handler)();
.B	sigset_t sa_mask;
.B	int	 sa_flags;
.B };
.PP
.B int sigaction(sig, vec, ovec)
.B int sig;
.B struct sigaction *vec, *ovec;
.fi
.SH Description
.NXB "sigaction system call"
.NXB "signal handler" "assigning"
The sigaction call is the POSIX equivalent to the
.MS sigvec 2
system call. This call behaves as described on the
.MS sigvec 2
reference page with the following modifications:
.IP \(bu 5
The
signal mask
is manipulated using the 
.MS sigsetops 3
functions.
.IP \(bu 5
A process can suppress the generation of the SIGCHLD when a child stops by
setting the SA_NOCLDSTOP bit in 
.IR sa_flags .
.IP \(bu 5
The SV_INTERRUPT flag is always set by the system when using
.MS sigaction 3 
in POSIX mode. The flag is set so that interrupted system calls will
fail with the EINTR error instead of getting restarted.
.SH Return Values
A 0 return value indicated that the call succeeded.  A \-1 return value
indicates an error occurred and
.I errno
is set to indicated the reason.
.SH Diagnostics
.NXR "sigaction system call" "diagnostics"
The
.PN sigaction
system call
fails and a new signal handler is not installed if one
of the following occurs:
.TP 15
[EFAULT]
Either
.I vec
or 
.I ovec
points to memory which is not a valid part of the process
address space.
.TP 15
[EINVAL]
.I Sig
is not a valid signal number.
.TP 15
[EINVAL]
An attempt is made to ignore or supply a handler for SIGKILL
or SIGSTOP.
.SH See Also
sigvec(2), sigsetops(3), sigprocmask(3),
sigsuspend(3), sigpending(2), setjmp(3), siginterrupt(3), tty(4)
.NXE "sigaction system call"
.NXE "signal handler" "assigning"