MPE/iX Shell and Utilities Reference Manual, Vol 2

Signals
This section provides an overview of implementation considerations you must understand when using
signals as they are implemented in MPE/iX
Shell and Utilities.
Supported Signal Functions
The MPE/iX Shell and Utilities library implements all signal functions defined by the POSIX.1 standard.
Signal Descriptions
Table A-5 describes the signal constants, declared in the <signal.h> header, that processes use to
refer to the signals that occur on the system. It also notes the default action taken by the system when
the signal is delivered, whether the signal is required for POSIX.1 conformance, and any MPE/iX imple-
mentation details.
Constant Default Description and Implementation Details
Action
Abnormal
termination
Abnormal termination signal (initiated by the
abort() function). Required for
POSIX.1 confor-
mance.
SIGABRT
Abnormal
termination
Timeout signal (initiated by the alarm() function).
Required for POSIX
.1 conformance.
SIGALRM
Abnormal
termination
Address violation. SIGBUS is not required for
POSIX.1 conformance, but is a signal commonly used
on
UNIX-based systems. A POSIX.1-conforming appli-
cation should not rely upon the generation of this sig-
nal by the system. The results are undefined if the
system generates this signal while the signal is either
blocked, ignored, or has a signal-handling function
that returns normally.
SIGBUS
Abnormal
termination
Erroneous arithmetic operation, such as division by
zero or a floating point exception. The results are
undefined if the system generates this signal while
the signal is either blocked, ignored, or has a signal-
handling function that returns normally. Required
for POSIX.1 conformance.
SIGFPE
Table A-5: Signals Required by POSIX.1
A-14 MPE/iX Implementation Considerations