assert(3) Library Functions Manual assert(3) assert - (libc -lc) #include void assert(bool expression); . expression ( ) assert() abort(3). assert() : prog: some_file.c:16: some_func: Assertion `val == 0' failed. NDEBUG assert() . NDEBUG assert() . . attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |assert() | | MT-Safe | +------------+------------------------------------+--------------------+ C11, POSIX.1-2008. C89, C99, POSIX.1-2001. C89 expression int C99 . assert() NDEBUG. . abort(3), assert_perror(3), exit(3) 3 . . : . 6.18 8 2026 assert(3)