ASSERT(3) Linux Programmer's Manual ASSERT(3)NAME
assert - abort the program if assertion is false
void assert(scalar expression);
If the macro NDEBUG was defined at the moment <assert.h> was last
included, the macro assert() generates no code, and hence does nothing
at all. Otherwise, the macro assert() prints an error message to stan‐
dard error and terminates the program by calling abort(3) if expression
is false (i.e., compares equal to zero).
The purpose of this macro is to help programmers find bugs in their
programs. The message "assertion failed in file foo.c, function
do_bar(), line 1287" is of no help at all to a user.
No value is returned.
POSIX.1-2001, C89, C99. In C89, expression is required to be of type
int and undefined behavior results if it is not, but in C99 it may have
any scalar type.
BUGSassert() is implemented as a macro; if the expression tested has side-
effects, program behavior will be different depending on whether NDEBUG
is defined. This may create Heisenbugs which go away when debugging is
SEE ALSOabort(3), assert_perror(3), exit(3)COLOPHON
This page is part of release 3.65 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2013-09-26 ASSERT(3)