[Solaris] Signals and Meanings

DETAIL DESCRIPTION

This is a description of Solaris 2.x Signals and their Meanings

SOLUTION SUMMARY

What is a signal?

An event notification (Similar to a software interrupt).

What are signals used for?

Abnormally interrupt a process and interprocess communication.

List of 2.x signals and their meanings:
-----------------------------------------
SIGHUP 1 - hangup
SIGINT 2 - interrupt (^c)
SIGQUIT 3 - quit (^, creates a core dump)
SIGILL 4 - illegal instruction (not reset when caught)
SIGTRAP 5 - trace trap (not reset when caught)
SIGABRT 6 - used by abort
SIGEMT 7 - EMT instruction
SIGFPE 8 - floating-point exception (when an integer error is seen)
SIGKILL 9 - kill (cannot be caught, ignored, masked or held)
SIGBUS 10 - bus error (address alignment problem, also when seg is stepped out of)
SIGSEGV 11 - segmentation violation (stepped on, didn't have perms)
SIGSYS 12 - bad argument to system call
SIGPIPE 13 - write on a pipe that is closed for reading
SIGALRM 14 - alarm clock (wall clock time)
SIGTERM 15 - software termination signal from kill
SIGUSR1 16 - user-defined signal 1 (not defined, ignored)
SIGUSR2 17 - user-defined signal 2 (not defined, ignored)
SIGCHLD 18 - child status change alias (POSIX) (exited, stopped or continued)
SIGPWR 19 - power-fail restart (3b2 only)
SIGWINCH 20 - window size change & keyboard focus
SIGURG 21 - urgent socket condition (used for out of band data)
SIGPOLL 22 - pollable event occurred
SIGIO 22 - socket I/O possible (SIGPOLL alias)
SIGSTOP 23 - stop (cannot be caught or ignored)
SIGTSTP 24 - user stop requested from tty
SIGCONT 25 - stopped process has been continued
SIGTTIN 26 - background tty read attempted
SIGTTOU 27 - background tty write attempted
SIGVTALRM 28 - virtual timer expired
SIGPROF 29 - profiling timer expired
SIGXCPU 30 - exceeded CPU limit
SIGXFSZ 31 - exceeded file size limit
SIGWAITING 32 - the process's LWPs are blocked
SIGLWP 33 - signal used by thread library
SIGFREEZE 34 - special signal used by CheckPoint/Resume
SIGTHAW 35 - special signal used by CheckPoint/Resume
SIGRTMIN 36 - First real time signal (will be used for POSIX real time)
SIGRTMAX 43 - Last real time signal
(The symbols SIGRTMIN and SIGRTMAX are evaluated dynamically in order to permit future configurability.)
---------------------------------------------------

See sys/signal.h

SIGINT terminates the process by default.

SIGQUIT terminates the process and create a core file.

SIGKILL 9 and SIGSTOP 23 cannot be ignored or caught.

SIGKILL has the highest priority when checking for signals (see fsig()).