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elf_hash(3E)

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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 arithmetic 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).

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