siginfo(5)							File Formats Manual							siginfo(5)

NAME

       siginfo - Details of signal generation

SYNOPSIS

       #include <siginfo.h>

DESCRIPTION

       The  siginfo  structure	provides processes with information on why a signal was generated, or a process that is monitoring child processes
       may receive information that specifies why a child process changed state.  See the sigaction(2) and  waitid(2)  reference  pages  for  more
       information.

       The  type  siginfo_t  contains the following members: Contains the system generated signal number.  Note that for the waitid function, this
       field is always SIGCHLD.  Contains, if non-zero, the errno that is associated with the signal.  Specifies a code  that  determines  whether
       the  signal  was generated by a user process, a specific signal, or by the kernel.  When the value of si_code is less than or equal to zero
       (0), the signal was generated by a user process and the siginfo structure contains the following additional members:

	      pid_t si_pid    /*sending process ID*/ uid_t si_uid    /*sending user ID*/

	      See the kill(2) and sigsend(2) reference pages for more information on these fields.

	      The following table describes the meaning of the code generated by a signal.  The table lists signals in alphabetical order.

	      ----------------------------------------------------------
	      Signal	Code		 Definition
	      ----------------------------------------------------------
	      SIGBUS	BUS_ADRALN	 invalid address alignment
			BUS_ADRERR	 non-existent physical address
			BUS_OBJERR	 object specific hardware error
	      SIGCHLD	CLD_EXITED	 child has exited
			CLD_KILLED	 child was killed
			CLD_DUMPED	 child terminated abnormally
			CLD_TRAPPED	 traced child has trapped
			CLD_STOPPED	 child has stopped
			CLD_CONTINUED	 stopped child has continued
			CLD_SIGEXITING	 child is about to exit because
					 it received a fatal signal
	      SIGILL	ILL_ILLOPC	 illegal opcode
			ILL_ILLOPN	 illegal operand
			ILL_ILLADR	 illegal addressing mode
			ILL_ILLTRP	 illegal trap
			ILL_PRVOPC	 privileged opcode
			ILL_PRVREG	 privileged register
			ILL_COPROC	 coprocessor error
			ILL_BADSTK	 internal stack error
	      SIGFPE	FPE_INTDIV	 integer divide by zero
			FPE_INTOVF	 integer overflow
			FPE_FLTDIV	 floating point divide by zero
			FPE_FLTOVF	 floating point overflow
			FPE_FLTUND	 floating point underflow
			FPE_FLTRES	 floating point inexact result
			FPE_FLTINV	 invalid  floating point opera-
					 tion
			FPE_FLTSUB	 subscript out of range
	      SIGPOLL	POLL_IN 	 data input available
			POLL_OUT	 output buffers available
			POLL_MSG	 input message available
			POLL_ERR	 I/O error
			POLL_PRI	 high priority input available
			POLL_HUP	 device disconnected
	      SIGSEGV	SEGV_MAPERR	 address not mapped to object

			SEGV_ACCERR	 invalid permissions for mapped
					 object
	      SIGTRAP	TRAP_BRKPT	 process breakpoint
			TRAP_TRACE	 process trace trap
	      ----------------------------------------------------------

	      When a signal is generated by the system, the meaning of the code is as follows:

	      ------------------------------------------------------------
	      Signal	Field		  Description
	      ------------------------------------------------------------
	      SIGILL	caddr_t si_addr   address of faulting instruction
	      SIGFPE
	      SIGSEGV	caddr_t si_addr   address of faulting memory
	      SIGBUS			  reference
	      SIGCHLD	pid_t si_pid	  child process ID
			int si_status	  exit value or signal
	      SIGPOLL	long si_band	  band event for POLL_IN,
					  POLL_OUT, or POLL_MSG
	      ------------------------------------------------------------

	      Note,  if  the  signal  is  SIGCHLD,  and  the si_code is equivalent to CLD_EXITED, si_status is equivalent to the exit value of the
	      process.	If si_code is not equivalent to CLD_EXITED, the si_status field is equivalent to the signal that  caused  the  process	to
	      change  state.   In some instances, si_addr may not be defined, but si_addr will appear on the same page as the faulting instruction
	      or memory reference.

SEE ALSO

       Functions: kill(2), sigaction(2), sigsend(2), waitid(2)

       Files: signal(4)

																	siginfo(5)