1.\" $NetBSD: end.3,v 1.8 2005/09/01 12:39:33 kleink Exp $ 2.\" 3.\" Copyright (c) 1986 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)end.3 6.4 (Berkeley) 1/24/94 31.\" 32.Dd September 1, 2005 33.Dt END 3 34.Os 35.Sh NAME 36.Nm end , 37.Nm etext , 38.Nm edata 39.Nd end boundaries of image segments 40.Sh SYNOPSIS 41.Vt extern int end; 42.Vt extern int etext; 43.Vt extern int edata; 44.Sh DESCRIPTION 45The globals 46.Va end , etext 47and 48.Va edata 49are program segment end addresses. 50.Pp 51.Va etext 52is located at the first address after the end of the text segment. 53.Pp 54.Va edata 55is located at the first address after the end of the initialized data segment. 56.Pp 57.Va end 58is located at the first address after the end of the data segment 59.Pq Tn BSS 60when the program is loaded. Use the 61.Xr sbrk 2 62.\".Fn sbrk 0 63system call with zero as its argument to find the current end of the 64data segment. 65.Sh SEE ALSO 66.Xr sbrk 2 , 67.Xr malloc 3 , 68.Xr a.out 5 69.Sh HISTORY 70An 71.Nm end 72manual page appeared in 73.At v6 . 74.Sh BUGS 75Traditionally, no variable existed that pointed to the start of the 76text segment because the text segment always started at address 77zero. Although it is no longer valid to make this assumption, no 78variable similar to the ones documented above exists to point to the 79start of the text segment. 80