elf_version(3E)   MISC. REFERENCE MANUAL PAGES    elf_version(3E)



NAME
     elfversion - coordinate ELF library  and  application  ver-
     sions

SYNOPSIS
     cc [flag ...] file ...  -lelf [library ...]

     #include <libelf.h>

     unsigned elfversion(unsigned ver);

DESCRIPTION
     As elf(3E) explains, the program, the library, and an object
     file have independent notions of the ``latest'' ELF version.
     elfversion 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 EVCURRENT.  If the library's  internal  version  (the
     highest  version  known  to  the library) is lower than that
     known by the program itself, the library may  lack  semantic
     knowledge  assumed by the program.  Accordingly, elfversion
     will not accept a working version unknown  to  the  library.
     Passing  ver  equal  to EVNONE causes elfversion to return
     the library's internal version, without altering the working
     version.   If  ver  is  a  version  known  to  the  library,
     elfversion returns the previous (or initial)  working  ver-
     sion   number.    Otherwise,  the  working  version  remains
     unchanged and elfversion returns EVNONE.

EXAMPLE
     The following excerpt from an application  program  protects
     itself from using an older library.
          if (elfversion(EVCURRENT) == EVNONE)
          {
                  /* library out of date */
                  /* recover from error */
          }

NOTES
     The working version should be the same for all operations on
     a  particular  elf descriptor.  Changing the version between
     operations on  a  descriptor  will  probably  not  give  the
     expected results.

SEE ALSO
     elf(3E), elfbegin(3E), elfxlate(3E).






                    Last change: ELF Library                    1