.TH ASSERT 3X .CT 2 debug_tune .SH NAME assert \(mi assertion checking .SH SYNOPSIS .B #include .PP .B void assert(expression); .SH DESCRIPTION .PP .I Assert is a macro that indicates .I expression is expected to be nonzero at this point in the program. It causes an .IR abort (3) with a diagnostic comment on the standard output when .I expression is zero. Compiling with the .IR cc (1) option .B -DNDEBUG effectively makes the expression always nonzero. .SH DIAGNOSTICS `Assertion failed: file .I f line .I n', where .I f is the source file and .I n the source line number of the .I assert statement.