HP-UX Reference (11i v2 07/12) - 3 Library Functions A-M (vol 6)

elf_version(3E) elf_version(3E)

NAME

elf_version - coordinate ELF library and application versions

SYNOPSIS

cc [ﬂag... ] ﬁle...

-lelf [library]...

#include <libelf.h>

unsigned elf_version(unsigned ver);

DESCRIPTION

As elf(3E) explains, the program, the library, and an object ﬁle have independent notions of the ‘‘latest’’

ELF version. elf_version lets a program determine the ELF library’s internal version. It further lets

the program specify what memory types it uses by giving its own working version, ver, to the library.

Every program that uses the ELF library must coordinate versions as described below.

The header ﬁle

libelf.h supplies the version to the program with the macro

EV_CURRENT . If the

library’s internal version (the highest version known to the library) is lower than that known by the pro-

gram itself, the library may lack semantic knowledge assumed by the program. Accordingly,

elf_version will not accept a working version unknown to the library.

Passing ver equal to EV_NONE causes elf_version to return the library’s internal version, without

altering the working version. If ver is a version known to the library, elf_version returns the previous

(or initial) working version number. Otherwise, the working version remains unchanged and

elf_version returns EV_NONE.

EXAMPLES

The following excerpt from an application program protects itself from using an older library.

if (elf_version(EV_CURRENT) == EV_NONE)

{

/* library out of date */

/* recover from error */

}

NOTICES

The working version should be the same for all operations on a particular elf descriptor. Changing the ver-

sion between operations on a descriptor will probably not give the expected results.