ASSERT(3) |
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, consisting of the text of the expression, the name of the source file, the line number and the enclosing function, is written to
stderr and the
abort(3) function is called, effectively terminating the program.
If expression is true, the assert() macro does nothing.
The assert() macro may be removed at compile time with the cc(1) option -DNDEBUG.
DIAGNOSTICS
The following diagnostic message is written to
stderr if
expression is false:
"assertion \"%s\" failed: file \"%s\", line %d, function \"%s\"\n", \
"expression", __FILE__, __LINE__, __func__);
STANDARDS
The assert() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).
HISTORY
A
assert macro appeared in Version 6 AT&T UNIX.
Information on the name of the enclosing function appeared in ISO/IEC 9899:1999 (“ISO C99”).