SIGNAL

Next the signals not in POSIX.1 but described in SUSv2.

(For the cases SIGSYS, SIGXCPU, SIGXFSZ, and on some architectures also SIGBUS, the Linux default action up to now (2.3.27) is A (terminate), while SUSv2 prescribes C (terminate and dump core).)

Next various other signals.

(Here − denotes that a signal is absent; there where three values are given, the first one is usually valid for alpha and sparc, the middle one for i386 and ppc and sh, the last one for mips. Signal 29 is SIGINFO / SIGPWR on an alpha but SIGLOST on a sparc.)

The letters in the "Action" column have the following meanings:

A

Default action is to terminate the process.

B

Default action is to ignore the signal.

C

Default action is to terminate the process and dump core.

D

Default action is to stop the process.

E

Signal cannot be caught.

F

Signal cannot be ignored.

POSIX.1

SIGIO and SIGLOST have the same value. The latter is commented out in the kernel source, but the build process of some software still thinks that signal 29 is SIGLOST.

kill(1), kill(2), setitimer(2)