sigaction(2) 맨 페이지 - 윈디하나의 솔라나라

개요

섹션
맨 페이지 이름
검색(S)

sigaction(2)

sigaction(2)                     System Calls                     sigaction(2)



NAME
       sigaction - detailed signal management

SYNOPSIS
       #include <signal.h>

       int sigaction(int sig, const struct sigaction *restrict act,
            struct sigaction *restrict oact);

DESCRIPTION
       The sigaction() function allows the calling process to examine or spec‐
       ify the action to be taken on delivery of a specific signal.  See  sig‐
       nal.h(3HEAD) for an explanation of general signal concepts.


       The  sig  argument  specifies the signal and can be assigned any of the
       signals specified in signal.h(3HEAD) except SIGKILL and SIGSTOP.


       If the argument act is not NULL, it points to  a  structure  specifying
       the new action to be taken when delivering sig. If the argument oact is
       not NULL, it points to a structure where the action previously  associ‐
       ated with sig is to be stored on return from sigaction().


       The sigaction structure includes the following members:

         void      (*sa_handler)();
         void      (*sa_sigaction)(int, siginfo_t *, void *);
         sigset_t  sa_mask;
         int       sa_flags;



       The  storage occupied by sa_handler and sa_sigaction may overlap, and a
       standard-conforming application (see standards(7)) must  not  use  both
       simultaneously.


       The  sa_handler  member identifies the action to be associated with the
       specified signal, if the SA_SIGINFO flag (see below) is cleared in  the
       sa_flags  field of the sigaction structure. It may take any of the val‐
       ues specified in signal.h(3HEAD) or that of  a  user  specified  signal
       handler.  If  the  SA_SIGINFO  flag  is  set in the sa_flags field, the
       sa_sigaction field specifies a signal-catching function.


       The sa_mask member specifies a set of signals to be blocked  while  the
       signal  handler  is active. On entry to the signal handler, that set of
       signals is added to the set of signals already being blocked  when  the
       signal is delivered. In addition, the signal that caused the handler to
       be executed will also be blocked, unless the SA_NODEFER flag  has  been
       specified.  SIGSTOP  and SIGKILL cannot be blocked (the system silently
       enforces this restriction).


       The sa_flags member specifies a set of flags used to modify the  deliv‐
       ery of the signal. It is formed by a logical OR of any of the following
       values:

       SA_ONSTACK      If set and the signal is caught, and if the thread that
                       is chosen to processes a delivered signal has an alter‐
                       nate signal stack declared with sigaltstack(2), then it
                       will  process  the signal on that stack. Otherwise, the
                       signal is delivered on the thread's normal stack.


       SA_RESETHAND    If set and the signal is caught, the disposition of the
                       signal  is  reset to SIG_DFL and the signal will not be
                       blocked on entry to the signal  handler  (SIGILL,  SIG‐
                       TRAP,  and  SIGPWR  cannot  be automatically reset when
                       delivered; the system silently enforces  this  restric‐
                       tion).


       SA_NODEFER      If set and the signal is caught, the signal will not be
                       automatically blocked by the kernel while it  is  being
                       caught.


       SA_RESTART      If  set  and  the  signal is caught, functions that are
                       interrupted by the execution of this  signal's  handler
                       are  transparently  restarted  by  the  system,  namely
                       fcntl(2), ioctl(2), wait(3C), waitid(2), and  the  fol‐
                       lowing   functions  on  slow  devices  like  terminals:
                       getmsg() and getpmsg() (see  getmsg(2));  putmsg()  and
                       putpmsg() (see putmsg(2)); pread(), read(), and readv()
                       (see read(2)); pwrite(),  write(),  and  writev()  (see
                       write(2));   recv(),  recvfrom(),  and  recvmsg()  (see
                       recv(3C)); and send(),  sendto(),  and  sendmsg()  (see
                       send(3C)).  Otherwise,  the  function  returns an EINTR
                       error.


       SA_SIGINFO      If cleared and the signal is caught, sig is  passed  as
                       the  only  argument to the signal-catching function. If
                       set and the signal is caught, two additional  arguments
                       are passed to the signal-catching function. If the sec‐
                       ond argument is not equal to NULL, it points to a  sig‐
                       info_t  structure  containing the reason why the signal
                       was generated (see siginfo.h(3HEAD)); the  third  argu‐
                       ment  points  to  a ucontext_t structure containing the
                       receiving process's context when the signal was  deliv‐
                       ered (see ucontext.h(3HEAD)).


       SA_NOCLDWAIT    If set and sig equals SIGCHLD, the system will not cre‐
                       ate zombie  processes  when  children  of  the  calling
                       process  exit.  If  the  calling  process  subsequently
                       issues a wait(3C), it blocks until all of  the  calling
                       process's  child  processes terminate, and then returns
                       −1 with errno set to ECHILD.


       SA_NOCLDSTOP    If set and sig equals SIGCHLD, SIGCHLD will not be sent
                       to the calling process when its child processes stop or
                       continue.


RETURN VALUES
       Upon successful completion, 0 is returned. Otherwise, −1  is  returned,
       errno  is  set  to  indicate  the  error,  and no new signal handler is
       installed.

ERRORS
       The sigaction() function will fail if:

       EINVAL    The value of the sig argument is not a valid signal number or
                 is  equal  to SIGKILL or SIGSTOP. In addition, if in a multi‐
                 threaded process, it is equal to  SIGWAITING,  SIGCANCEL,  or
                 SIGLWP.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       tab()  box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE TYPEAT‐
       TRIBUTE VALUE _ Interface  StabilityCommitted  _  MT-LevelAsync-Signal-
       Safe _ StandardSee standards(7).


SEE ALSO
       kill(1),  exit(2),  fcntl(2),  getmsg(2),  Intro(2), ioctl(2), kill(2),
       pause(2),   putmsg(2),   read(2),    sigaltstack(2),    sigprocmask(2),
       sigsend(2), sigsuspend(2), waitid(2), write(2), psiginfo(3C), recv(3C),
       send(3C), signal(3C), sigsetops(3C), wait(3C),  siginfo.h(3HEAD),  sig‐
       nal.h(3HEAD), ucontext.h(3HEAD), attributes(7), standards(7)

NOTES
       The handler routine can be declared:

         void handler (int sig, siginfo_t *sip, ucontext_t *ucp);



       The  sig  argument  is the signal number. The sip argument is a pointer
       (to space on the stack) to a siginfo_t structure, which provides  addi‐
       tional  detail  about the delivery of the signal. The ucp argument is a
       pointer (again to  space  on  the  stack)  to  a  ucontext_t  structure
       (defined  in  <sys/ucontext.h>)  which contains the context from before
       the signal. It is not recommended that ucp be used by  the  handler  to
       restore the context from before the signal delivery.



Oracle Solaris 11.4               9 Jul 2018                      sigaction(2)
맨 페이지 내용의 저작권은 맨 페이지 작성자에게 있습니다.
RSS ATOM XHTML 5 CSS3