iwordexp.c

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	default:
	  assert (! "Unrecognised action!");
	}
    }

  free (env); env = NULL;
  free (pattern); pattern = NULL;

  if (seen_hash)
    {
      char param_length[21];
      param_length[20] = '\0';
      *word = w_addstr (*word, word_length, max_length,
			itoa_word (value ? strlen (value) : 0,
				    &param_length[20], 10, 0));
      if (free_value)
	{
	  assert (value != NULL);
	  free (value);
	}

      return *word ? 0 : WRDE_NOSPACE;
    }

  if (value == NULL)
    return 0;

  if (quoted || !pwordexp)
    {
      /* Quoted - no field split */
      *word = w_addstr (*word, word_length, max_length, value);
      if (free_value)
	free (value);

      return *word ? 0 : WRDE_NOSPACE;
    }
  else
    {
      /* Need to field-split */
      char *value_copy = strdup (value); /* Don't modify value */
      char *field_begin = value_copy;
      int seen_nonws_ifs = 0;

      if (free_value)
	free (value);

      if (value_copy == NULL)
	goto no_space;

      do
	{
	  char *field_end = field_begin;
	  char *next_field;

	  /* If this isn't the first field, start a new word */
	  if (field_begin != value_copy)
	    {
	      if (w_addword (pwordexp, *word) == WRDE_NOSPACE)
		{
		  free (value_copy);
		  goto no_space;
		}

	      *word = w_newword (word_length, max_length);
	    }

	  /* Skip IFS whitespace before the field */
	  field_begin += strspn (field_begin, ifs_white);

	  if (!seen_nonws_ifs && *field_begin == 0)
	    /* Nothing but whitespace */
	    break;

	  /* Search for the end of the field */
	  field_end = field_begin + strcspn (field_begin, ifs);

	  /* Set up pointer to the character after end of field and
             skip whitespace IFS after it. */
	  next_field = field_end + strspn (field_end, ifs_white);

	  /* Skip at most one non-whitespace IFS character after the field */
	  seen_nonws_ifs = 0;
	  if (*next_field && strchr (ifs, *next_field))
	    {
	      seen_nonws_ifs = 1;
	      next_field++;
	    }

	  /* Null-terminate it */
	  *field_end = 0;

	  /* Tag a copy onto the current word */
	  *word = w_addstr (*word, word_length, max_length, field_begin);

	  if (*word == NULL && *field_begin != '\0')
	    {
	      free (value_copy);
	      goto no_space;
	    }

	  field_begin = next_field;
	}
      while (seen_nonws_ifs || *field_begin);

      free (value_copy);
    }

  return 0;

success:
  error = 0;
  goto do_error;

no_space:
  error = WRDE_NOSPACE;
  goto do_error;

syntax:
  error = WRDE_SYNTAX;

do_error:
  if (env)
    free (env);

  if (pattern)
    free (pattern);

  return error;
}

static int
internal_function
parse_dollars (char **word, size_t *word_length, size_t *max_length,
	       const char *words, size_t *offset, int flags,
	       wordexp_t *pwordexp, const char *ifs, const char *ifs_white,
	       int quoted)
{
  /* We are poised _at_ "$" */
  switch (words[1 + *offset])
    {
    case '"':
    case '\'':
    case 0:
      *word = w_addchar (*word, word_length, max_length, '$');
      return *word ? 0 : WRDE_NOSPACE;

    case '(':
      if (words[2 + *offset] == '(')
	{
	  /* Differentiate between $((1+3)) and $((echo);(ls)) */
	  int i = 3 + *offset;
	  int depth = 0;
	  while (words[i] && !(depth == 0 && words[i] == ')'))
	    {
	      if (words[i] == '(')
		++depth;
	      else if (words[i] == ')')
		--depth;

	      ++i;
	    }

	  if (words[i] == ')' && words[i + 1] == ')')
	    {
	      (*offset) += 3;
	      /* Call parse_arith -- 0 is for "no brackets" */
	      return parse_arith (word, word_length, max_length, words, offset,
				  flags, 0);
	    }
	}

      if (flags & WRDE_NOCMD)
	return WRDE_CMDSUB;

      (*offset) += 2;
      return parse_comm (word, word_length, max_length, words, offset, flags,
			 quoted? NULL : pwordexp, ifs, ifs_white);

    case '[':
      (*offset) += 2;
      /* Call parse_arith -- 1 is for "brackets" */
      return parse_arith (word, word_length, max_length, words, offset, flags,
			  1);

    case '{':
    default:
      ++(*offset);	/* parse_param needs to know if "{" is there */
      return parse_param (word, word_length, max_length, words, offset, flags,
			   pwordexp, ifs, ifs_white, quoted);
    }
}

static int
internal_function
parse_backtick (char **word, size_t *word_length, size_t *max_length,
		const char *words, size_t *offset, int flags,
		wordexp_t *pwordexp, const char *ifs, const char *ifs_white)
{
  /* We are poised just after "`" */
  int error;
  int squoting = 0;
  size_t comm_length;
  size_t comm_maxlen;
  char *comm = w_newword (&comm_length, &comm_maxlen);

  for (; words[*offset]; ++(*offset))
    {
      switch (words[*offset])
	{
	case '`':
	  /* Go -- give the script to the shell */
	  error = exec_comm (comm, word, word_length, max_length, flags,
			     pwordexp, ifs, ifs_white);
	  free (comm);
	  return error;

	case '\\':
	  if (squoting)
	    {
	      error = parse_qtd_backslash (&comm, &comm_length, &comm_maxlen,
					   words, offset);

	      if (error)
		{
		  free (comm);
		  return error;
		}

	      break;
	    }

	  ++(*offset);
	  error = parse_backslash (&comm, &comm_length, &comm_maxlen, words,
				   offset);

	  if (error)
	    {
	      free (comm);
	      return error;
	    }

	  break;

	case '\'':
	  squoting = 1 - squoting;
	default:
	  comm = w_addchar (comm, &comm_length, &comm_maxlen, words[*offset]);
	  if (comm == NULL)
	    return WRDE_NOSPACE;
	}
    }

  /* Premature end */
  free (comm);
  return WRDE_SYNTAX;
}

static int
internal_function
parse_dquote (char **word, size_t *word_length, size_t *max_length,
	      const char *words, size_t *offset, int flags,
	      wordexp_t *pwordexp, const char * ifs, const char * ifs_white)
{
  /* We are poised just after a double-quote */
  int error;

  for (; words[*offset]; ++(*offset))
    {
      switch (words[*offset])
	{
	case '"':
	  return 0;

	case '$':
	  error = parse_dollars (word, word_length, max_length, words, offset,
				 flags, pwordexp, ifs, ifs_white, 1);
	  /* The ``1'' here is to tell parse_dollars not to
	   * split the fields.  It may need to, however ("$@").
	   */
	  if (error)
	    return error;

	  break;

	case '`':
	  if (flags & WRDE_NOCMD)
	    return WRDE_CMDSUB;

	  ++(*offset);
	  error = parse_backtick (word, word_length, max_length, words,
				  offset, flags, NULL, NULL, NULL);
	  /* The first NULL here is to tell parse_backtick not to
	   * split the fields.
	   */
	  if (error)
	    return error;

	  break;

	case '\\':
	  error = parse_qtd_backslash (word, word_length, max_length, words,
				       offset);

	  if (error)
	    return error;

	  break;

	default:
	  *word = w_addchar (*word, word_length, max_length, words[*offset]);
	  if (*word == NULL)
	    return WRDE_NOSPACE;
	}
    }

  /* Unterminated string */
  return WRDE_SYNTAX;
}

/*
 * wordfree() is to be called after pwordexp is finished with.
 */

void
iwordfree (wordexp_t *pwordexp)
{

  /* wordexp can set pwordexp to NULL */
  if (pwordexp && pwordexp->we_wordv)
    {
      char **wordv = pwordexp->we_wordv;

      for (wordv += pwordexp->we_offs; *wordv; ++wordv)
	free (*wordv);

      free (pwordexp->we_wordv);
      pwordexp->we_wordv = NULL;
    }
}

/*
 * wordexp()
 */

int
iwordexp (const char *words, wordexp_t *pwordexp, int flags)
{
  size_t words_offset;
  size_t word_length;
  size_t max_length;
  char *word = w_newword (&word_length, &max_length);
  int error;
  char *ifs;
  char ifs_white[4];
  wordexp_t old_word = *pwordexp;

  if (flags & WRDE_REUSE)
    {
      /* Minimal implementation of WRDE_REUSE for now */
      iwordfree (pwordexp);
      old_word.we_wordv = NULL;
    }

  if ((flags & WRDE_APPEND) == 0)
    {
      pwordexp->we_wordc = 0;

      if (flags & WRDE_DOOFFS)
	{
	  pwordexp->we_wordv = calloc (1 + pwordexp->we_offs, sizeof (char *));
	  if (pwordexp->we_wordv == NULL)
	    {
	      error = WRDE_NOSPACE;
	      goto do_error;
	    }
	}
      else
	{
	  pwordexp->we_wordv = calloc (1, sizeof (char *));
	  if (pwordexp->we_wordv == NULL)
	    {
	      error = WRDE_NOSPACE;
	      goto do_error;
	    }

	  pwordexp->we_offs = 0;
	}
    }

  /* Find out what the field separators are.
   * There are two types: whitespace and non-whitespace.
   */
  ifs = getenv ("IFS");

  if (!ifs)
    /* IFS unset - use <space><tab><newline>. */
    ifs = strcpy (ifs_white, " \t\n");
  else
    {
      char *ifsch = ifs;
      char *whch = ifs_white;

      /* Start off with no whitespace IFS characters */
      ifs_white[0] = '\0';

      while (*ifsch != '\0')
	{
	  if ((*ifsch == ' ') || (*ifsch == '\t') || (*ifsch == '\n'))
	    {
	      /* Whitespace IFS.  See first whether it is already in our
		 collection.  */
	      char *runp = ifs_white;

	      while (runp < whch && *runp != '\0' && *runp != *ifsch)
		++runp;

	      if (runp == whch)
		*whch++ = *ifsch;
	    }

	  ++ifsch;
	}
      *whch = '\0';
    }

  for (words_offset = 0 ; words[words_offset] ; ++words_offset)
    switch (words[words_offset])
      {
      case '\\':
	error = parse_backslash (&word, &word_length, &max_length, words,
				 &words_offset);

	if (error)
	  goto do_error;

	break;

      case '$':
	error = parse_dollars (&word, &word_length, &max_length, words,
			       &words_offset, flags, pwordexp, ifs, ifs_white,
			       0);

	if (error)
	  goto do_error;

	break;

      case '`':
	if (flags & WRDE_NOCMD)
	  {
	    error = WRDE_CMDSUB;
	    goto do_error;
	  }

	++words_offset;
	error = parse_backtick (&word, &word_length, &max_length, words,
				&words_offset, flags, pwordexp, ifs,
				ifs_white);

	if (error)
	  goto do_error;

	break;

      case '"':
	++words_offset;
	error = parse_dquote (&word, &word_length, &max_length, words,
			      &words_offset, flags, pwordexp, ifs, ifs_white);

	if (error)
	  goto do_error;

	if (!word_length)
	  {
	    error = w_addword (pwordexp, NULL);

	    if (error)
	      return error;
	  }

	break;

      case '\'':
	++words_offset;
	error = parse_squote (&word, &word_length, &max_length, words,
			      &words_offset);

	if (error)
	  goto do_error;

	if (!word_length)
	  {
	    error = w_addword (pwordexp, NULL);

	    if (error)
	      return error;
	  }

	break;

      case '~':
	error = parse_tilde (&word, &word_length, &max_length, words,
			     &words_offset, pwordexp->we_wordc);

	if (error)
	  goto do_error;

	break;

      case '*':
      case '[':
      case '?':
	error = parse_glob (&word, &word_length, &max_length, words,
			    &words_offset, flags, pwordexp, ifs, ifs_white);

	if (error)
	  goto do_error;

	break;

      default:
	/* Is it a word separator? */
	if (strchr (" \t", words[words_offset]) == NULL)
	  {
	    char ch = words[words_offset];

	    /* Not a word separator -- but is it a valid word char? */
	    if (strchr ("\n|&;<>(){}", ch))
	      {
		/* Fail */
		error = WRDE_BADCHAR;
		goto do_error;
	      }

	    /* "Ordinary" character -- add it to word */
	    word = w_addchar (word, &word_length, &max_length,
			      ch);
	    if (word == NULL)
	      {
		error = WRDE_NOSPACE;
		goto do_error;
	      }

	    break;
	  }

	/* If a word has been delimited, add it to the list. */
	if (word != NULL)
	  {
	    error = w_addword (pwordexp, word);
	    if (error)
	      goto do_error;
	  }

	word = w_newword (&word_length, &max_length);
      }

  /* End of string */

  /* There was a word separator at the end */
  if (word == NULL) /* i.e. w_newword */
    return 0;

  /* There was no field separator at the end */
  return w_addword (pwordexp, word);

do_error:
  /* Error:
   *	free memory used (unless error is WRDE_NOSPACE), and
   *	set pwordexp members back to what they were.
   */

  if (word != NULL)
    free (word);

  if (error == WRDE_NOSPACE)
    return WRDE_NOSPACE;

  if ((flags & WRDE_APPEND) == 0)
    iwordfree (pwordexp);

  *pwordexp = old_word;
  return error;
}

static char *itoa (unsigned long long int value, char *buflim,
                    unsigned int base, int upper_case)
{
/* This actually only does base 10 but it'll do for the purpose of wordexp */
char s[64];
char *begin;
sprintf(s, "%lld", value);
begin = (char *)((long)buflim - strlen(s));
strcpy(begin, s);
return begin;
}