개요

• 솔라나라에 설명된 어플리케이션에 대해 맨 페이지를 찾아 출력한다.
• MAN 페이지에 대한 설명은 윈디하나의 솔라나라: MAN 페이지을 참고하자.
• svcadm(1M)을 검색하려면 섹션에서 1M 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.

sigfpe(3c)

Standard C Library Functions                                        sigfpe(3C)



NAME
       sigfpe - signal handling for specific SIGFPE codes

SYNOPSIS
       #include <floatingpoint.h>
       #include <siginfo.h>

       sigfpe_handler_type sigfpe(sigfpe_code_type code,
            sigfpe_handler_type hdl);

DESCRIPTION
       The  sigfpe()  function allows signal handling to be specified for par‐
       ticular SIGFPE codes. A call to sigfpe() defines a new handler hdl  for
       a  particular  SIGFPE  code and returns the old handler as the value of
       the function sigfpe(). Normally handlers are specified as  pointers  to
       functions;   the   special   cases   SIGFPE_IGNORE,  SIGFPE_ABORT,  and
       SIGFPE_DEFAULT allow ignoring, dumping core using abort(3C), or default
       handling   respectively.   Default  handling  is  to  dump  core  using
       abort(3C).


       The code argument is usually one of the  five  IEEE754-related   SIGFPE
       codes:

         FPE_FLTRES   fp_inexact − floating-point inexact result
         FPE_FLTDIV   fp_division − floating-point division by zero
         FPE_FLTUND   fp_underflow − floating-point underflow
         FPE_FLTOVF   fp_overflow − floating-point overflow
         FPE_FLTINV   fp_invalid − floating-point invalid operation



       Three  steps  are required to intercept an IEEE754-related  SIGFPE code
       with sigfpe():

           1.     Set up a handler with sigfpe().


           2.     Enable the relevant IEEE754 trapping capability in the hard‐
                  ware, perhaps by using assembly-language instructions.


           3.     Perform   a  floating-point  operation  that  generates  the
                  intended IEEE754 exception.




       The sigfpe() function never changes floating-point hardware  mode  bits
       affecting  IEEE754 trapping. No IEEE754-related  SIGFPE signals will be
       generated unless those hardware mode bits are enabled.


       SIGFPE signals can be handled  using  sigfpe(),  sigaction(2)  or  sig‐
       nal(3C).  In  a particular program, to avoid confusion, use only one of
       these interfaces to handle SIGFPE signals.

EXAMPLES
       Example 1 Example Of A User-Specified Signal Handler




       A user-specified signal handler might look like this:


         #include <floatingpoint.h>
         #include <siginfo.h>
         #include <ucontext.h>
         /*
         * The sample_handler prints out a message then commits suicide.
         */
         void
         sample_handler(int sig, siginfo_t *sip, ucontext_t *uap) {
              char *label;
                 switch (sip−>si_code) {
              case FPE_FLTINV: label = "invalid operand"; break;
              case FPE_FLTRES: label = "inexact"; break;
              case FPE_FLTDIV: label = "division-by-zero"; break;
              case FPE_FLTUND: label = "underflow"; break;
              case FPE_FLTOVF: label = "overflow"; break;
              default: label = "???"; break;
              }
              fprintf(stderr,
                 "FP exception %s (0x%x) occurred at address %p.\n",
                 label, sip−>si_code, (void *) sip−>si_addr);
              abort();
         }




       and it might be set up like this:


         #include <floatingpoint.h>
         #include <siginfo.h>
         #include <ucontext.h>
         extern void sample_handler(int, siginfo_t *, ucontext_t *);
         main(void) {
               sigfpe_handler_type hdl, old_handler1, old_handler2;
         /*
          * save current fp_overflow and fp_invalid handlers; set the new
         * fp_overflow handler to sample_handler() and set the new
         * fp_invalid handler to SIGFPE_ABORT (abort on invalid)
         */
             hdl = (sigfpe_handler_type) sample_handler;
             old_handler1 = sigfpe(FPE_FLTOVF, hdl);
             old_handler2 = sigfpe(FPE_FLTINV, SIGFPE_ABORT);
             ...
         /*
          * restore old fp_overflow and fp_invalid handlers
          */
              sigfpe(FPE_FLTOVF, old_handler1);
              sigfpe(FPE_FLTINV, old_handler2);
         }


FILES
       /usr/include/floatingpoint.h




       /usr/include/siginfo.h




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 _ MT-LevelSafe


SEE ALSO
       sigaction(2),     abort(3C),     signal(3C),    floatingpoint.h(3HEAD),
       attributes(7)

DIAGNOSTICS
       The sigfpe() function returns (void(*)())-1 if code is not  zero  or  a
       defined SIGFPE code.



Oracle Solaris 11.4               4 May 2004                        sigfpe(3C)