elf_rand(3E)                   (ELF Library)                   elf_rand(3E)


   NAME
         elf_rand - random archive member access

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

         #include <libelf.h>
         size_t elf_rand(Elf *elf, size_t offset);

   DESCRIPTION
         elf_rand, elf_next, and elf_begin manipulate simple object files and
         archives.  elf is an ELF descriptor previously returned from
         elf_begin.

         elf_rand 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 elf_getarsym(3E) for more information
         about archive member offsets.  When elf_rand 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 (elf_rand(elf, (size_t)SARMAG) == SARMAG)
                              return 0;
                      return -1;
              }

   SEE ALSO
         elf(3E), elf_begin(3E), elf_getarsym(3E), elf_next(3E), ar(4).









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