DOCUMENT ID: 1479-02

SYNOPSIS:    Solaris 2.x Signals and their Meanings

OS RELEASE:  Solaris 2.x

PRODUCT:     

KEYWORDS:    signals interrupts caught ignored


DESCRIPTION:

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


SOLUTION:

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()).


DATE APPROVED: 07/28/95