C Primer Plus, Fourth Edition

The Assert Library

The assert library, supported by the assert.h header file, is a small one designed to help with debugging programs. It consists of a macro named assert(). It takes as its argument an integer expression. If the expression evaluates as false (non-zero), the assert() macro writes an error message to the standard error stream (stderr) and calls the abort() function, which terminates the program. (The abort() function is prototyped in the stdlib.h header file.) The idea is to identify critical locations in a program where certain conditions should be true and to use the assert() statement to terminate the program if the condition is not true. Typically, the argument is a relational or logical expression. If assert() does abort the ...