.\" (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)
.\" This file can be distributed under the terms of the GNU General Public
.\" License.
.\" Modified Sat Jul 24 21:42:42 1993 by Rik Faith (faith@cs.unc.edu)
.TH ASSERT 3  "April 4, 1993" "GNU" "Linux Programmer's Manual"
.SH NAME
assert \- Abort the program if assertion is false.
.SH SYNOPSIS
.nf
.B #include <assert.h>
.sp
.BI "void assert (int " "expression" ");"
.fi
.SH DESCRIPTION
.B assert()
prints an error message to standard output and terminates the program
by calling
.B abort()
if
.B expression
is false (i.e. nonzero).  This only happens when the macro
.B NDEBUG
is undefined.
.SH "RETURN VALUE"
No value is returned.
.SH "CONFORMS TO"
ANSI - C
.SH "BUGS"
.B assert()
is implemented as a macro; if the expression tested has side - effects,
program behaviour will be different depending on wether
.B NDEBUG
is defined. This may create Heisenbugs which go away when debugging is turned on.
.SH SEE ALSO
.BR exit "(3), " abort (3)