elf_hash.3e (2010 09)

elf_hash(3E) elf_hash(3E)

NAME

elf_hash - compute hash value

SYNOPSIS

cc [ﬂag... ] ﬁle...

-lelf [library ] ...

#include <libelf.h>

unsigned long elf_hash(const char *name);

DESCRIPTION

elf_hash computes a hash value, given a null terminated string, name. The returned hash value, h,

can be used as a bucket index, typically after computing h mod x to ensure appropriate bounds.

Hash tables may be built on one machine and used on another because

elf_hash uses unsigned arith-

metic to avoid possible differences in various machines’ signed arithmetic. Although name is shown as

char* above, elf_hash treats it as unsigned char*

to avoid sign extension differences. Using

char* eliminates type conﬂicts with expressions such as

elf_hash ("name").

ELF ﬁles’ symbol hash tables are computed using this function (see elf_getdata (3E) and elf_xlate (3E)).

The hash value returned is guaranteed not to be the bit pattern of all ones (

˜0UL).