xref: /freebsd/contrib/elftoolchain/libelf/elf_hash.3 (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1.\" Copyright (c) 2006,2008 Joseph Koshy.  All rights reserved.
2.\"
3.\" Redistribution and use in source and binary forms, with or without
4.\" modification, are permitted provided that the following conditions
5.\" are met:
6.\" 1. Redistributions of source code must retain the above copyright
7.\"    notice, this list of conditions and the following disclaimer.
8.\" 2. Redistributions in binary form must reproduce the above copyright
9.\"    notice, this list of conditions and the following disclaimer in the
10.\"    documentation and/or other materials provided with the distribution.
11.\"
12.\" This software is provided by Joseph Koshy ``as is'' and
13.\" any express or implied warranties, including, but not limited to, the
14.\" implied warranties of merchantability and fitness for a particular purpose
15.\" are disclaimed.  in no event shall Joseph Koshy be liable
16.\" for any direct, indirect, incidental, special, exemplary, or consequential
17.\" damages (including, but not limited to, procurement of substitute goods
18.\" or services; loss of use, data, or profits; or business interruption)
19.\" however caused and on any theory of liability, whether in contract, strict
20.\" liability, or tort (including negligence or otherwise) arising in any way
21.\" out of the use of this software, even if advised of the possibility of
22.\" such damage.
23.\"
24.\" $Id: elf_hash.3 3639 2018-10-14 14:07:02Z jkoshy $
25.\"
26.Dd August 15, 2006
27.Dt ELF_HASH 3
28.Os
29.Sh NAME
30.Nm elf_hash
31.Nd compute a hash value for a string
32.Sh LIBRARY
33.Lb libelf
34.Sh SYNOPSIS
35.In libelf.h
36.Ft "unsigned long"
37.Fn elf_hash "const char *name"
38.Sh DESCRIPTION
39Function
40.Fn elf_hash
41computes a portable hash value for the null terminated string
42pointed to by argument
43.Ar name .
44.Pp
45The hash value returned is will be identical across
46machines of different architectures.
47This allows hash tables to be built on one machine and
48correctly used on another of a different architecture.
49The hash value returned is also guaranteed
50.Em not
51to be the bit pattern of all ones (~0UL).
52.Sh IMPLEMENTATION NOTES
53The library internally uses unsigned 32 bit arithmetic to compute
54the hash value.
55.Sh SEE ALSO
56.Xr elf 3 ,
57.Xr gelf 3
58