ASSERT(3) BSD Library Functions Manual ASSERT(3)NAME
assert — expression verification macro
SYNOPSIS
#include <assert.h>
assert(expression);
DESCRIPTION
The assert() macro tests the given expression and if it is false, the
calling process is terminated. A diagnostic message is written to stderr
and the function abort(3) is called, effectively terminating the program.
If expression is true, the assert() macro does nothing.
The assert() macro may be removed at compile time by defining NDEBUG as a
macro (e.g., by using the cc(1) option -DNDEBUG).
EXAMPLES
The assertion:
assert(1 == 0);
generates a diagnostic message similar to the following:
Assertion failed: (1 == 0), function main, file assertion.c, line
100.
SEE ALSOabort(3)STANDARDS
The assert() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).
HISTORY
An assert macro appeared in Version 6 AT&T UNIX.
BSD January 26, 1999 BSD