1.\" $NetBSD: assert.3,v 1.5 1994/11/30 15:24:30 jtc Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)assert.3 8.1 (Berkeley) 6/9/93 35.\" 36.Dd June 9, 1993 37.Dt ASSERT 3 38.Os 39.Sh NAME 40.Nm assert 41.Nd expression verification macro 42.Sh SYNOPSIS 43.Fd #include <assert.h> 44.Fn assert expression 45.Sh DESCRIPTION 46The 47.Fn assert 48macro tests the given 49.Ar expression 50and if it is false, 51the calling process is terminated. 52A 53diagnostic message is written to 54.Em stderr 55and the 56.Xr abort 3 57function is called, effectively terminating the program. 58.Pp 59If 60.Ar expression 61is true, 62the 63.Fn assert 64macro does nothing. 65.Pp 66The 67.Fn assert 68macro 69may be removed at compile time with 70the 71.Xr cc 1 72option 73.Fl DNDEBUG . 74.Sh DIAGNOSTICS 75The following diagnostic message is written to 76.Em stderr 77if 78.Ar expression 79is false: 80.Bd -literal -offset indent 81"assertion \e"%s\e" failed: file \e"%s\e", line %d\en", \e 82 "expression", __FILE__, __LINE__); 83.Ed 84.Sh SEE ALSO 85.Xr cc 1 , 86.Xr abort 3 87.Sh STANDARDS 88The 89.Fn assert 90macro conforms to 91.St -ansiC . 92.Sh HISTORY 93A 94.Nm assert 95macro appeared in 96.At v6 . 97