Abort a program if a test is false.

This function is compatible with the following targets:

ANSI

BeOS

EMB/RTOS

Mac OS

Palm OS

Win32

#include <assert.h>

void assert(int expression);

Parameters for this function are:

expression

int

A boolean expression being evaluated

If expression is false the assert() macro outputs a diagnostic message to stderr and calls abort(). The diagnostic message has the form

file: line test -- assertion failed

abort -- terminating

where

• file is the source file,
• line is the line number, and
• test is the failed expression.

"abort."

#undef NDEBUG
		/* Make sure that assert() is enabled */
#include <assert.h>
#include <stdio.h>

int main(void)
{
	int x = 100, y = 5;
	printf("assert test.\n");

/*This assert will output a message and abort the program */
	assert(x > 1000);	 
	printf("This will not execute if NDEBUG is undefined\n");
	return 0;
}
/* Output:
assert test.
foo.c:12 x > 1000 -- assertion failed
abort -- terminating
*/