/* Quote a blob so that it can be used in C literals.

   Copyright (C) 2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

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

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <support/support.h>

#include <support/xmemstream.h>

char *

support_quote_blob (const void *blob, size_t length)

{

  struct xmemstream out;

  xopen_memstream (&out;;

  const unsigned char *p = blob;

  for (size_t i = 0; i < length; ++i)

    {

      unsigned char ch = p[i];

      /* Use C backslash escapes for those control characters for

         which they are defined.  */

      switch (ch)

        {

          case '\a':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('a', out.out);

            break;

          case '\b':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('b', out.out);

            break;

          case '\f':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('f', out.out);

            break;

          case '\n':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('n', out.out);

            break;

          case '\r':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('r', out.out);

            break;

          case '\t':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('t', out.out);

            break;

          case '\v':

            putc_unlocked ('\\', out.out);

            putc_unlocked ('v', out.out);

            break;

          case '\\':

          case '\'':

          case '\"':

            putc_unlocked ('\\', out.out);

            putc_unlocked (ch, out.out);

            break;

        default:

          if (ch < ' ' || ch > '~')

            /* Use octal sequences because they are fixed width,

               unlike hexadecimal sequences.  */

            fprintf (out.out, "\\%03o", ch);

          else

            putc_unlocked (ch, out.out);

        }

    }

  xfclose_memstream (&out;;

  return out.buffer;

}