/* uudecode utility.
   Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc.

   This product 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 2, or (at your option)
   any later version.

   This product 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 product; see the file COPYING.  If not, write to
   the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */

/* Copyright (c) 1983 Regents of the University of California.
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:
   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
   3. All advertising materials mentioning features or use of this software
      must display the following acknowledgement:
	 This product includes software developed by the University of
	 California, Berkeley and its contributors.
   4. Neither the name of the University nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   SUCH DAMAGE.  */

/* Reworked to GNU style by Ian Lance Taylor, ian@airs.com, August 93.  */

#include "system.h"

/*=====================================================================\
| uudecode [FILE ...]						       |
| 								       |
| Create the specified FILE, decoding as you go.  Used with uuencode.  |
\=====================================================================*/

#include <pwd.h>
#include "getopt.h"

struct passwd *getpwnam ();

static struct option longopts[] =
{
  { "version", no_argument, NULL, 'v' },
  { "help", no_argument, NULL, 'h' },
  { "output-file", required_argument, NULL, 'o' },
  { NULL, 0, NULL, 0 }
};

static int read_stduu __P ((const char *inname));
static int read_base64 __P ((const char *inname));
static int decode __P ((const char *, const char *));
static void usage __P ((int));

/* The name this program was run with. */
const char *program_name;

/* Single character decode.  */
#define	DEC(Char) (((Char) - ' ') & 077)


static int
read_stduu (inname)
     const char *inname;
{
  char buf[2 * BUFSIZ];

  while (1)
    {
      int n;
      char *p;

      if (fgets (buf, sizeof(buf), stdin) == NULL)
	{
	  error (0, 0, _("%s: Short file"), inname);
	  return 1;
	}
      p = buf;

      /* N is used to avoid writing out all the characters at the end of
	 the file.  */

      n = DEC (*p);
      if (n <= 0)
	break;
      for (++p; n > 0; p += 4, n -= 3)
	{
	  char ch;

	  if (n >= 3)
	    {
	      ch = DEC (p[0]) << 2 | DEC (p[1]) >> 4;
	      putchar (ch);
	      ch = DEC (p[1]) << 4 | DEC (p[2]) >> 2;
	      putchar (ch);
	      ch = DEC (p[2]) << 6 | DEC (p[3]);
	      putchar (ch);
	    }
	  else
	    {
	      if (n >= 1)
		{
		  ch = DEC (p[0]) << 2 | DEC (p[1]) >> 4;
		  putchar (ch);
		}
	      if (n >= 2)
		{
		  ch = DEC (p[1]) << 4 | DEC (p[2]) >> 2;
		  putchar (ch);
		}
	    }
	}
    }

  if (fgets (buf, sizeof(buf), stdin) == NULL ||
#if O_TEXT   /* MSDOS-style EOL. */
      strcmp (buf, "end\r\n") &&
#endif
      strcmp (buf, "end\n"))
    {
      error (0, 0, _("%s: No `end' line"), inname);
      return 1;
    }

  return 0;
}

static int
read_base64 (inname)
     const char *inname;
{
  static const char b64_tab[256] =
  {
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*000-007*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*010-017*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*020-027*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*030-037*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*040-047*/
    '\177', '\177', '\177', '\76',  '\177', '\177', '\177', '\77',  /*050-057*/
    '\64',  '\65',  '\66',  '\67',  '\70',  '\71',  '\72',  '\73',  /*060-067*/
    '\74',  '\75',  '\177', '\177', '\177', '\100', '\177', '\177', /*070-077*/
    '\177', '\0',   '\1',   '\2',   '\3',   '\4',   '\5',   '\6',   /*100-107*/
    '\7',   '\10',  '\11',  '\12',  '\13',  '\14',  '\15',  '\16',  /*110-117*/
    '\17',  '\20',  '\21',  '\22',  '\23',  '\24',  '\25',  '\26',  /*120-127*/
    '\27',  '\30',  '\31',  '\177', '\177', '\177', '\177', '\177', /*130-137*/
    '\177', '\32',  '\33',  '\34',  '\35',  '\36',  '\37',  '\40',  /*140-147*/
    '\41',  '\42',  '\43',  '\44',  '\45',  '\46',  '\47',  '\50',  /*150-157*/
    '\51',  '\52',  '\53',  '\54',  '\55',  '\56',  '\57',  '\60',  /*160-167*/
    '\61',  '\62',  '\63',  '\177', '\177', '\177', '\177', '\177', /*170-177*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*200-207*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*210-217*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*220-227*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*230-237*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*240-247*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*250-257*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*260-267*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*270-277*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*300-307*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*310-317*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*320-327*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*330-337*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*340-347*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*350-357*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*360-367*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*370-377*/
  };
  unsigned char buf[2 * BUFSIZ];

  while (1)
    {
      int last_data = 0;
      unsigned char *p;

      if (fgets (buf, sizeof(buf), stdin) == NULL)
	{
	  error (0, 0, _("%s: Short file"), inname);
	  return 1;
	}
      p = buf;

      if (memcmp (buf, "====", 4) == 0)
	break;
      if (last_data != 0)
	{
	  error (0, 0, _("%s: data following `=' padding character"), inname);
	  return 1;
	}

      /* The following implementation of the base64 decoding might look
	 a bit clumsy but I only try to follow the POSIX standard:
	 ``All line breaks or other characters not found in the table
	   [with base64 characters] shall be ignored by decoding
	   software.''  */
      while (*p != '\n')
	{
	  char c1, c2, c3;

	  while ((b64_tab[*p] & '\100') != 0)
	    if (*p == '\n' || *p++ == '=')
	      break;
	  if (*p == '\n')
	    /* This leaves the loop.  */
	    continue;
	  c1 = b64_tab[*p++];

	  while ((b64_tab[*p] & '\100') != 0)
	    if (*p == '\n' || *p++ == '=')
	      {
		error (0, 0, _("%s: illegal line"), inname);
		return 1;
	      }
	  c2 = b64_tab[*p++];

	  while (b64_tab[*p] == '\177')
	    if (*p++ == '\n')
	      {
		error (0, 0, _("%s: illegal line"), inname);
		return 1;
	      }
	  if (*p == '=')
	    {
	      putchar (c1 << 2 | c2 >> 4);
	      last_data = 1;
	      break;
	    }
	  c3 = b64_tab[*p++];

	  while (b64_tab[*p] == '\177')
	    if (*p++ == '\n')
	      {
		error (0, 0, _("%s: illegal line"), inname);
		return 1;
	      }
	  putchar (c1 << 2 | c2 >> 4);
	  putchar (c2 << 4 | c3 >> 2);
	  if (*p == '=')
	    {
	      last_data = 1;
	      break;
	    }
	  else
	    putchar (c3 << 6 | b64_tab[*p++]);
	}
    }

  return 0;
}


static int
decode (inname, forced_outname)
     const char *inname;
     const char *forced_outname;
{
  struct passwd *pw;
  register int n;
  register char *p;
  int mode, n1;
  char buf[2 * BUFSIZ];
  char *outname;
  int do_base64 = 0;

  /* Search for header line.  */

  while (1)
    {
      if (fgets (buf, sizeof (buf), stdin) == NULL)
	{
	  error (0, 0, _("%s: No `begin' line"), inname);
	  return 1;
	}

      if (strncmp (buf, "begin", 5) == 0)
	{
	  if (sscanf (buf, "begin-base64 %o %s", &mode, buf) == 2)
	    {
	      do_base64 = 1;
	      break;
	    }
	  else if (sscanf (buf, "begin %o %s", &mode, buf) == 2)
	    break;
	}
    }

  /* If the output file name is given on the command line this rules.  */
  if (forced_outname != NULL)
    outname = (char *) forced_outname;
  else
    {
      /* Handle ~user/file format.  */

      if (buf[0] != '~')
	outname = buf;
      else
	{
	  p = buf + 1;
	  while (!IS_SLASH (*p))
	    ++p;
	  if (*p == '\0')
	    {
	      error (0, 0, _("%s: Illegal ~user"), inname);
	      return 1;
	    }
	  *p++ = '\0';
	  pw = getpwnam (buf + 1);
	  if (pw == NULL)
	    {
	      error (0, 0, _("%s: No user `%s'"), inname, buf + 1);
	      return 1;
	    }
	  n = strlen (pw->pw_dir);
	  n1 = strlen (p);
	  outname = (char *) alloca ((size_t) (n + n1 + 2));
	  memcpy (outname + n + 1, p, (size_t) (n1 + 1));
	  memcpy (outname, pw->pw_dir, (size_t) n);
	  outname[n] = '/';
	}
    }

  /* Create output file and set mode.  */

  if (strcmp (outname, "/dev/stdout") != 0 && strcmp (outname, "-") != 0
      && (freopen (outname, FREOPEN_WRITE, stdout) == NULL
#if HAVE_FCHMOD
	  || fchmod (fileno (stdout), mode & (S_IRWXU | S_IRWXG | S_IRWXO))
#else
	  || chmod (outname, mode & (S_IRWXU | S_IRWXG | S_IRWXO))
#endif
	  ))
    {
      error (0, errno, "%s: %s", outname, inname);
      return 1;
    }

  /* We differenciate decoding standard UU encoding and base64.  A
     common function would only slow down the program.  */

  /* For each input line:  */
  if (do_base64)
    return read_base64 (inname);
  else
    return read_stduu (inname);
}

static void
usage (status)
     int status;
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      printf (_("Usage: %s [FILE]...\n"), program_name);
      fputs (_("\
Mandatory arguments to long options are mandatory to short options too.\n\
  -o, --output-file=FILE   direct output to FILE\n\
      --help               display this help and exit\n\
      --version            output version information and exit\n"), stdout);
      fputs (_("Report bugs to <bug-gnu-utils@prep.ai.mit.edu>.\n"), stdout);
    }
  exit (status);
}

int
main (argc, argv)
     int argc;
     char *const *argv;
{
  int opt;
  int exit_status;
  const char *outname;

  program_name = argv[0];
  outname = NULL;
  setlocale (LC_ALL, "");

  /* Set the text message domain.  */
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  while (opt = getopt_long (argc, argv, "o:", longopts, (int *) NULL),
	 opt != EOF)
    {
      switch (opt)
	{
	case 'h':
	  usage (EXIT_SUCCESS);

	case 'o':
	  outname = optarg;
	  break;

	case 'v':
	  printf ("%s (GNU %s) %s\n", basename (program_name),
		  PACKAGE, VERSION);
	  /* xgettext: no-wrap */
	  printf (_("Copyright (C) %s Free Software Foundation, Inc.\n"
"This is free software; see the source for copying conditions.  There is NO\n"
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
),
		  "1994, 1995, 1996");
	  exit (EXIT_SUCCESS);

	case 0:
	  break;

	default:
	  usage (EXIT_FAILURE);
	}
    }

  if (optind == argc)
    exit_status = decode ("stdin", outname) == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
  else
    {
      exit_status = EXIT_SUCCESS;
      do
	{
	  if (freopen (argv[optind], FREOPEN_READ, stdin) != NULL)
	    {
	      if (decode (argv[optind], outname) != 0)
		exit_status = EXIT_FAILURE;
	    }
	  else
	    {
	      error (0, errno, "%s", argv[optind]);
	      exit_status = EXIT_FAILURE;
	    }
	  optind++;
	}
      while (optind < argc);
    }

  exit (exit_status);
}