xref: /freebsd/share/man/man3/end.3 (revision a0409676120c1e558d0ade943019934e0f15118d)
1.\" Copyright (c) 1986
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 3. Neither the name of the University nor the names of its contributors
13.\"    may be used to endorse or promote products derived from this software
14.\"    without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\"	@(#)end.3	6.4 (Berkeley) 1/24/94
29.\" $FreeBSD$
30.\"
31.Dd August 28, 2000
32.Dt END 3
33.Os
34.Sh NAME
35.Nm end ,
36.Nm etext ,
37.Nm edata
38.Nd end boundaries of image segments
39.Sh SYNOPSIS
40.Vt extern end ;
41.Vt extern etext ;
42.Vt extern edata ;
43.Sh DESCRIPTION
44The globals
45.Va end , etext
46and
47.Va edata
48are program segment end addresses.
49.Pp
50.Va etext
51is the first address after the end of the text segment.
52.Pp
53.Va edata
54is the first address after the end of the initialized data segment.
55.Pp
56.Va end
57is the first address after the end of the data segment
58.Pq Tn BSS
59when the program is loaded.
60Use 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
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 zero.
77Although 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