Error handling

<assert.h>

void assert(expression)

• If the expression is false, it raises an Assertion failed during execution

• Otherwise, it executes the following instructions

<signal.h>

Provides the means for handling exceptional conditions (signals). A signal is generated when an error or an external event occurs.

Types of signal

MACROs in <signal.h>:

MACRO	Description
SIGABRT	Abnormal termination (possibly caused by a call to the abort function)
SIGFPE	Error during an arithmetic operation (can be caused by division by zero or overflow)
SIGILL	Invalid instruction
SIGINT	Interrupt
SIGSEGV	Invalid memory access
SIGTERM	Termination request

Functions

void (*signal(int sig , void (*func )(int))) (int);

where:

• a signal sig

• a function func of type void, which will be called by the program in the event that the specified signal sig is raised

  • the function func is defined as a handler and manages the error

• the return value of signal is a pointer to the previous handler (usually not used)

Pre-defined handlers

Handler	Description
SIG_DFL	Default handling of the specified signal
SIG_ING	Specifies to ignore the specified signal

int raise(int sig);

It generates the signal sig, passed as an argument.