elf_rand(3E)              UNIX System V(ELF Library)               elf_rand(3E)


NAME
      elfrand - random archive member access

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

      #include <libelf.h>
      sizet elfrand(Elf *elf, sizet offset);

DESCRIPTION
      elfrand, elfnext, and elfbegin manipulate simple object files and
      archives.  elf is an ELF descriptor previously returned from elfbegin.

      elfrand provides random archive processing, preparing elf to access an
      arbitrary archive member.  elf must be a descriptor for the archive
      itself, not a member within the archive.  offset gives the byte offset
      from the beginning of the archive to the archive header of the desired
      member.  See elfgetarsym(3E) for more information about archive member
      offsets.  When elfrand works, it returns offset.  Otherwise it returns
      0, because an error occurred, elf was null, or the file was not an
      archive (no archive member can have a zero offset).  A program may mix
      random and sequential archive processing.

EXAMPLE
      An archive starts with a ``magic string'' that has SARMAG bytes; the
      initial archive member follows immediately.  An application could thus
      provide the following function to rewind an archive (the function returns
      -1 for errors and 0 otherwise).

           #include <ar.h>
           #include <libelf.h>

           int
           rewindelf(Elf *elf)
           {
                   if (elfrand(elf, (sizet)SARMAG) == SARMAG)
                           return 0;
                   return -1;
           }

SEE ALSO
      elf(3E), elfbegin(3E), elfgetarsym(3E), elfnext(3E), ar(4)












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