SIGINFO(2) BSD System Calls Manual SIGINFO(2)NAMEsiginfo — signal information
SYNOPSIS
#include <signal.h>
DESCRIPTIONsiginfo is a structure type which contains information about a signal
delivered to a process.
siginfo includes the following members:
int si_signo;
int si_errno;
int si_code;
si_signo contains the signal number generated by the system.
If si_errno is non-zero, then it contains a system specific error number
associated with this signal. This number is defined in errno(2).
If si_code is less than or equal to zero, the signal was generated by a
user process or a user requested service:
SI_USER The signal was generated via kill(2). The siginfo structure
contains the following additional members:
pid_t si_pid;
uid_t si_uid;
The si_pid field contains the pid of the sending process and
the si_uid field contains the user id of the sending process.
SI_TIMER The signal was generated because a timer set by
timer_settime(2) has expired. The siginfo structure contains
the following additional members:
sigval_t si_value;
The si_value field contains the value set via
timer_create(2).
SI_ASYNCIO The signal was generated by completion of an asynchronous I/O
operation. The siginfo structure contains the following
additional members:
int si_fd;
long si_band;
The si_fd argument contains the file descriptor number on
which the operation was completed and the si_band field con‐
tains the side and priority of the operation. If the opera‐
tion was a normal read, si_band will contain POLLIN |
POLLRDNORM; on an out-of-band read it will contain POLLPRI |
POLLRDBAND; on a normal write it will contain POLLOUT |
POLLWRNORM; on an out-of-band write it will contain POLLPRI |
POLLWRBAND.
If si_code is positive, then it contains a signal specific reason why the
signal was generated:
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 operation
FPE_FLTSUB Subscript out of range
SIGSEGV
SEGV_MAPERR Address not mapped to object
SEGV_ACCERR Invalid permissions for mapped object
SIGBUS
BUS_ADRALN Invalid address alignment
BUS_ADRERR Non-existant physical address
BUS_OBJERR Object specific hardware error
SIGTRAP
TRAP_BRKPT Process breakpoint
TRAP_TRACE Process trace trap
SIGCHLD
CLD_EXITED Child has exited
CLD_KILLED Child has terminated abnormally but did not cre‐
ate a core file
CLD_DUMPED Child has terminated abnormally and created a
core file
CLD_TRAPPED Traced child has trapped
CLD_STOPPED Child has stopped
CLD_CONTINUED Stopped child has continued
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
For SIGILL, SIGFPE, and SIGTRAP the siginfo structure contains the fol‐
lowing additional members:
void *si_addr;
int si_trap;
si_addr contains the address of the faulting instruction and si_trap con‐
tains a hardware specific reason.
For SIGBUS and SIGSEGV the siginfo structure contains the following addi‐
tional members:
void *si_addr;
int si_trap;
si_addr contains the address of the faulting data and si_trap contains a
hardware specific reason.
For SIGPOLL the siginfo structure contains the following additional mem‐
bers:
int si_fd;
long si_band;
The si_fd argument contains the file descriptor number on which the oper‐
ation was completed and the si_band field contains the side and priority
of the operation as described above.
Finally, for SIGCHLD the siginfo structure contains the following addi‐
tional members:
pid_t si_pid;
uid_t si_uid;
int si_status;
clock_t si_utime;
clock_t si_stime;
The si_pid field contains the pid of the process who's status changed,
the si_uid field contains the user id of the that process, the si_status
field contains a status code described in waitpid(2), and the si_utime
and si_stime fields contain the user and system process accounting time.
STANDARDS
The siginfo type conforms to X/Open System Interfaces and Headers Issue 5
(“XSH5”).
HISTORY
The siginfo functionality first appeared in AT&T System V Release 4 UNIX.
BSD July 26, 2010 BSD
