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(libc.info)Standard Signals

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Standard Signals
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   This section lists the names for various standard kinds of signals
and describes what kind of event they mean.  Each signal name is a macro
which stands for a positive integer--the "signal number" for that kind
of signal.  Your programs should never make assumptions about the
numeric code for a particular kind of signal, but rather refer to them
always by the names defined here.  This is because the number for a
given kind of signal can vary from system to system, but the meanings of
the names are standardized and fairly uniform.

   The signal names are defined in the header file `signal.h'.

 - Macro: int NSIG
     The value of this symbolic constant is the total number of signals
     defined.  Since the signal numbers are allocated consecutively,
     `NSIG' is also one greater than the largest defined signal number.

Program Error Signals

Used to report serious program errors.

Termination Signals

Used to interrupt and/or terminate the

program.

Alarm Signals

Used to indicate expiration of timers.

Asynchronous I/O Signals

Used to indicate input is available.

Job Control Signals

Signals used to support job control.

Operation Error Signals

Used to report operational system errors.

Miscellaneous Signals

Miscellaneous Signals.

Signal Messages

Printing a message describing a signal.