ASSERT(3C) Standard C Library Functions ASSERT(3C)


NAME


assert - verify program assertion

SYNOPSIS


#include <assert.h>

void assert(int expression);


DESCRIPTION


The assert() macro inserts diagnostics into applications. When executed,
if expression is FALSE (zero), assert() prints the error message

Assertion failed: expression, file xyz, line nnn


on the standard error output and aborts. In the error message, xyz is the
name of the source file and nnn the source line number of the assert()
statement. These are respectively the values of the preprocessor macros
__FILE__ and __LINE__.


Since assert() is implemented as a macro, the expression may not contain
any string literals.


Compiling with the preprocessor option -DNDEBUG or with the preprocessor
control statement #define NDEBUG ahead of the #include <assert.h>
statement, will stop assertions from being compiled into the program.


Messages printed from this function are in the native language specified
by the LC_MESSAGES locale category. See setlocale(3C).

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|MT-Level | Safe |
+--------------------+-------------------+
|Standard | See standards(5). |
+--------------------+-------------------+

SEE ALSO


abort(3C), gettext(3C), setlocale(3C), attributes(5), standards(5)


March 30, 2005 ASSERT(3C)