assert
Evaluates an expression and when the result is FALSE,prints a diagnostic message and aborts the program.
void assert( int expression );
Example
/* ASSERT.C:In this program,the analyze_string function uses
* the assert function to test several conditions related to
* string and length.If any of the conditions fails,the program
* prints a message indicating what caused the failure.
*/
#include
#include
#include
void analyze_string( char *string ); /* Prototype */
void main( void )
{
char test1[] = "abc",*test2 = NULL,test3[] = "";
printf ( "Analyzing string '%s'n",test1 );
analyze_string( test1 );
printf ( "Analyzing string '%s'n",test2 );
analyze_string( test2 );
printf ( "Analyzing string '%s'n",test3 );
analyze_string( test3 );
}
/* Tests a string to see if it is NULL,*/
/* empty,or longer than 0 characters */
void analyze_string( char * string )
{
assert( string != NULL ); /* Cannot be NULL */
assert( *string != ' ' ); /* Cannot be empty */
assert( strlen( string ) > 2 ); /* Length must exceed 2 */
}
