/* Test program for elf_strptr function.

   Copyright (C) 2015 Red Hat, Inc.

   This file is part of elfutils.

   This file is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   elfutils is distributed in the hope that it will be useful, but

   WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#include <errno.h>

#include <fcntl.h>

#include <inttypes.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include ELFUTILS_HEADER(elf)

#include <gelf.h>

int

main (int argc, char *argv[])

{

  if (argc != 2)

    {

      printf ("No ELF file given as argument");

      exit (1);

    }

  const char *fname = argv[1];

  // Initialize libelf.

  elf_version (EV_CURRENT);

  /* Read the ELF from disk now.  */

  int fd = open (fname, O_RDONLY);

  if (fd == -1)

    {

      printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));

      exit (1);

    }

  Elf *elf = elf_begin (fd, ELF_C_READ, NULL);

  if (elf == NULL)

    {

      printf ("cannot create ELF descriptor read-only: %s\n", elf_errmsg (-1));

      exit (1);

    }

  size_t ndx;

  if (elf_getshdrstrndx (elf, &ndx) != 0)

    {

      printf ("cannot get section header table index: %s\n", elf_errmsg (-1));

      exit (1);

    }

  if (ndx == SHN_UNDEF)

    {

      printf ("ELF file `%s' doesn't have a section header table index", fname);

      exit (1);

    }

  Elf_Scn *scn = elf_getscn (elf, ndx);

  if (scn == NULL)

    {

      printf ("Couldn't get section %zd: %s\n", ndx, elf_errmsg (-1));

      exit (1);

    }

  void print_strings (void)

  {

    GElf_Shdr shdr_mem;

    GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);

    printf ("Strings in section %zd (%s):\n", ndx,

	    ((shdr->sh_flags & SHF_COMPRESSED) != 0

	     ? "compressed" : "uncompressed"));

    size_t off = 0;

    const char *str = elf_strptr (elf, ndx, off);

    while (str != NULL)

      {

	printf ("[%zx] '%s'\n", off, str);

	off += strlen (str) + 1;

	str = elf_strptr (elf, ndx, off);

      }

  }

  if (elf_compress (scn, ELFCOMPRESS_ZLIB, 0) < 0)

    {

      printf ("Couldn't compress section %zd: %s\n", ndx, elf_errmsg (-1));

      exit (1);

    }

  print_strings ();

  if (elf_compress (scn, 0, 0) < 0)

    {

      printf ("Couldn't decompress section %zd: %s\n", ndx, elf_errmsg (-1));

      exit (1);

    }

  print_strings ();

  if (elf_end (elf) != 0)

    {

      printf ("failure in elf_end: %s\n", elf_errmsg (-1));

      exit (1);

    }

  close (fd);

  return 0;

}