subst.c

android-w.song.android.widget

#ifdef INCLUDE_UNUSED
/* Return the length of S, skipping over quoted characters */
static int
quoted_strlen (s)
     char *s;
{
  register char *p;
  int i;

  i = 0;
  for (p = s; *p; p++)
    {
      if (*p == CTLESC)
	{
	  p++;
	  if (*p == 0)
	    return (i + 1);
	}
      i++;
    }

  return i;
}
#endif

/* Find the first occurrence of character C in string S, obeying shell
   quoting rules.  If (FLAGS & ST_BACKSL) is non-zero, backslash-escaped
   characters are skipped.  If (FLAGS & ST_CTLESC) is non-zero, characters
   escaped with CTLESC are skipped. */
static char *
quoted_strchr (s, c, flags)
     char *s;
     int c, flags;
{
  register char *p;

  for (p = s; *p; p++)
    {
      if (((flags & ST_BACKSL) && *p == '\\')
	    || ((flags & ST_CTLESC) && *p == CTLESC))
	{
	  p++;
	  if (*p == '\0')
	    return ((char *)NULL);
	  continue;
	}
      else if (*p == c)
	return p;
    }
  return ((char *)NULL);
}

/* Return 1 if CHARACTER appears in an unquoted portion of
   STRING.  Return 0 otherwise.  CHARACTER must be a single-byte character. */
static int
unquoted_member (character, string)
     int character;
     char *string;
{
  size_t slen;
  int sindex, c;
  DECLARE_MBSTATE;

  slen = strlen (string);
  sindex = 0;
  while (c = string[sindex])
    {
      if (c == character)
	return (1);

      switch (c)
	{
	default:
	  ADVANCE_CHAR (string, slen, sindex);
	  break;

	case '\\':
	  sindex++;
	  if (string[sindex])
	    ADVANCE_CHAR (string, slen, sindex);
	  break;

	case '\'':
	  sindex = skip_single_quoted (string, slen, ++sindex);
	  break;

	case '"':
	  sindex = skip_double_quoted (string, slen, ++sindex);
	  break;
	}
    }
  return (0);
}

/* Return 1 if SUBSTR appears in an unquoted portion of STRING. */
static int
unquoted_substring (substr, string)
     char *substr, *string;
{
  size_t slen;
  int sindex, c, sublen;
  DECLARE_MBSTATE;

  if (substr == 0 || *substr == '\0')
    return (0);

  slen = strlen (string);
  sublen = strlen (substr);
  for (sindex = 0; c = string[sindex]; )
    {
      if (STREQN (string + sindex, substr, sublen))
	return (1);

      switch (c)
	{
	case '\\':
	  sindex++;
	  if (string[sindex])
	    ADVANCE_CHAR (string, slen, sindex);
	  break;

	case '\'':
	  sindex = skip_single_quoted (string, slen, ++sindex);
	  break;

	case '"':
	  sindex = skip_double_quoted (string, slen, ++sindex);
	  break;

	default:
	  ADVANCE_CHAR (string, slen, sindex);
	  break;
	}
    }
  return (0);
}

/* Most of the substitutions must be done in parallel.  In order
   to avoid using tons of unclear goto's, I have some functions
   for manipulating malloc'ed strings.  They all take INDX, a
   pointer to an integer which is the offset into the string
   where manipulation is taking place.  They also take SIZE, a
   pointer to an integer which is the current length of the
   character array for this string. */

/* Append SOURCE to TARGET at INDEX.  SIZE is the current amount
   of space allocated to TARGET.  SOURCE can be NULL, in which
   case nothing happens.  Gets rid of SOURCE by freeing it.
   Returns TARGET in case the location has changed. */
INLINE char *
sub_append_string (source, target, indx, size)
     char *source, *target;
     int *indx, *size;
{
  if (source)
    {
      int srclen, n;

      srclen = STRLEN (source);
      if (srclen >= (int)(*size - *indx))
	{
	  n = srclen + *indx;
	  n = (n + DEFAULT_ARRAY_SIZE) - (n % DEFAULT_ARRAY_SIZE);
	  target = (char *)xrealloc (target, (*size = n));
	}

      FASTCOPY (source, target + *indx, srclen);
      *indx += srclen;
      target[*indx] = '\0';

      free (source);
    }
  return (target);
}

#if 0
/* UNUSED */
/* Append the textual representation of NUMBER to TARGET.
   INDX and SIZE are as in SUB_APPEND_STRING. */
char *
sub_append_number (number, target, indx, size)
     intmax_t number;
     int *indx, *size;
     char *target;
{
  char *temp;

  temp = itos (number);
  return (sub_append_string (temp, target, indx, size));
}
#endif

/* Extract a substring from STRING, starting at SINDEX and ending with
   one of the characters in CHARLIST.  Don't make the ending character
   part of the string.  Leave SINDEX pointing at the ending character.
   Understand about backslashes in the string.  If (flags & SX_VARNAME)
   is non-zero, and array variables have been compiled into the shell,
   everything between a `[' and a corresponding `]' is skipped over.
   If (flags & SX_NOALLOC) is non-zero, don't return the substring, just
   update SINDEX.  If (flags & SX_REQMATCH) is non-zero, the string must
   contain a closing character from CHARLIST. */
static char *
string_extract (string, sindex, charlist, flags)
     char *string;
     int *sindex;
     char *charlist;
     int flags;
{
  register int c, i;
  int found;
  size_t slen;
  char *temp;
  DECLARE_MBSTATE;

  slen = (MB_CUR_MAX > 1) ? strlen (string + *sindex) + *sindex : 0;
  i = *sindex;
  found = 0;
  while (c = string[i])
    {
      if (c == '\\')
	{
	  if (string[i + 1])
	    i++;
	  else
	    break;
	}
#if defined (ARRAY_VARS)
      else if ((flags & SX_VARNAME) && c == '[')
	{
	  int ni;
	  /* If this is an array subscript, skip over it and continue. */
	  ni = skipsubscript (string, i, 0);
	  if (string[ni] == ']')
	    i = ni;
	}
#endif
      else if (MEMBER (c, charlist))
	{
	  found = 1;
	  break;
	}

      ADVANCE_CHAR (string, slen, i);
    }

  /* If we had to have a matching delimiter and didn't find one, return an
     error and let the caller deal with it. */
  if ((flags & SX_REQMATCH) && found == 0)
    {
      *sindex = i;
      return (&extract_string_error);
    }
  
  temp = (flags & SX_NOALLOC) ? (char *)NULL : substring (string, *sindex, i);
  *sindex = i;
  
  return (temp);
}

/* Extract the contents of STRING as if it is enclosed in double quotes.
   SINDEX, when passed in, is the offset of the character immediately
   following the opening double quote; on exit, SINDEX is left pointing after
   the closing double quote.  If STRIPDQ is non-zero, unquoted double
   quotes are stripped and the string is terminated by a null byte.
   Backslashes between the embedded double quotes are processed.  If STRIPDQ
   is zero, an unquoted `"' terminates the string. */
static char *
string_extract_double_quoted (string, sindex, stripdq)
     char *string;
     int *sindex, stripdq;
{
  size_t slen;
  char *send;
  int j, i, t;
  unsigned char c;
  char *temp, *ret;		/* The new string we return. */
  int pass_next, backquote, si;	/* State variables for the machine. */
  int dquote;
  DECLARE_MBSTATE;

  slen = strlen (string + *sindex) + *sindex;
  send = string + slen;

  pass_next = backquote = dquote = 0;
  temp = (char *)xmalloc (1 + slen - *sindex);

  j = 0;
  i = *sindex;
  while (c = string[i])
    {
      /* Process a character that was quoted by a backslash. */
      if (pass_next)
	{
	  /* XXX - take another look at this in light of Interp 221 */
	  /* Posix.2 sez:

	     ``The backslash shall retain its special meaning as an escape
	     character only when followed by one of the characters:
		$	`	"	\	<newline>''.

	     If STRIPDQ is zero, we handle the double quotes here and let
	     expand_word_internal handle the rest.  If STRIPDQ is non-zero,
	     we have already been through one round of backslash stripping,
	     and want to strip these backslashes only if DQUOTE is non-zero,
	     indicating that we are inside an embedded double-quoted string. */

	     /* If we are in an embedded quoted string, then don't strip
		backslashes before characters for which the backslash
		retains its special meaning, but remove backslashes in
		front of other characters.  If we are not in an
		embedded quoted string, don't strip backslashes at all.
		This mess is necessary because the string was already
		surrounded by double quotes (and sh has some really weird
		quoting rules).
		The returned string will be run through expansion as if
		it were double-quoted. */
	  if ((stripdq == 0 && c != '"') ||
	      (stripdq && ((dquote && (sh_syntaxtab[c] & CBSDQUOTE)) || dquote == 0)))
	    temp[j++] = '\\';
	  pass_next = 0;

add_one_character:
	  COPY_CHAR_I (temp, j, string, send, i);
	  continue;
	}

      /* A backslash protects the next character.  The code just above
	 handles preserving the backslash in front of any character but
	 a double quote. */
      if (c == '\\')
	{
	  pass_next++;
	  i++;
	  continue;
	}

      /* Inside backquotes, ``the portion of the quoted string from the
	 initial backquote and the characters up to the next backquote
	 that is not preceded by a backslash, having escape characters
	 removed, defines that command''. */
      if (backquote)
	{
	  if (c == '`')
	    backquote = 0;
	  temp[j++] = c;
	  i++;
	  continue;
	}

      if (c == '`')
	{
	  temp[j++] = c;
	  backquote++;
	  i++;
	  continue;
	}

      /* Pass everything between `$(' and the matching `)' or a quoted
	 ${ ... } pair through according to the Posix.2 specification. */
      if (c == '$' && ((string[i + 1] == LPAREN) || (string[i + 1] == LBRACE)))
	{
	  int free_ret = 1;

	  si = i + 2;
	  if (string[i + 1] == LPAREN)
	    ret = extract_command_subst (string, &si, 0);
	  else
	    ret = extract_dollar_brace_string (string, &si, Q_DOUBLE_QUOTES, 0);

	  temp[j++] = '$';
	  temp[j++] = string[i + 1];

	  /* Just paranoia; ret will not be 0 unless no_longjmp_on_fatal_error
	     is set. */
	  if (ret == 0 && no_longjmp_on_fatal_error)
	    {
	      free_ret = 0;
	      ret = string + i + 2;
	    }

	  for (t = 0; ret[t]; t++, j++)
	    temp[j] = ret[t];
	  temp[j] = string[si];

	  if (string[si])
	    {
	      j++;
	      i = si + 1;
	    }
	  else
	    i = si;

	  if (free_ret)
	    free (ret);
	  continue;
	}

      /* Add any character but a double quote to the quoted string we're
	 accumulating. */
      if (c != '"')
	goto add_one_character;

      /* c == '"' */
      if (stripdq)
	{
	  dquote ^= 1;
	  i++;
	  continue;
	}

      break;
    }
  temp[j] = '\0';

  /* Point to after the closing quote. */
  if (c)
    i++;
  *sindex = i;

  return (temp);
}

/* This should really be another option to string_extract_double_quoted. */
static int
skip_double_quoted (string, slen, sind)
     char *string;
     size_t slen;
     int sind;
{
  int c, i;
  char *ret;
  int pass_next, backquote, si;
  DECLARE_MBSTATE;

  pass_next = backquote = 0;
  i = sind;
  while (c = string[i])
    {
      if (pass_next)
	{
	  pass_next = 0;
	  ADVANCE_CHAR (string, slen, i);
	  continue;
	}
      else if (c == '\\')
	{
	  pass_next++;
	  i++;
	  continue;
	}
      else if (backquote)
	{
	  if (c == '`')
	    backquote = 0;
	  ADVANCE_CHAR (string, slen, i);
	  continue;
	}
      else if (c == '`')
	{
	  backquote++;
	  i++;
	  continue;
	}
      else if (c == '$' && ((string[i + 1] == LPAREN) || (string[i + 1] == LBRACE)))
	{
	  si = i + 2;
	  if (string[i + 1] == LPAREN)
	    ret = extract_command_subst (string, &si, SX_NOALLOC);
	  else
	    ret = extract_dollar_brace_string (string, &si, Q_DOUBLE_QUOTES, SX_NOALLOC);

	  i = si + 1;
	  continue;
	}
      else if (c != '"')
	{
	  ADVANCE_CHAR (string, slen, i);
	  continue;
	}
      else
	break;
    }

  if (c)
    i++;

  return (i);
}

/* Extract the contents of STRING as if it is enclosed in single quotes.
   SINDEX, when passed in, is the offset of the character immediately
   following the opening single quote; on exit, SINDEX is left pointing after
   the closing single quote. */