strlcpy (string + 4, hstring, l - 4);
strlcpy (string + 4, hstring, l + 1);
static char *history_find_word __P((char *, int));static char *quote_breaks __P((char *));/* Variables exported by this file. *//* The character that represents the start of a history expansion   request.  This is usually `!'. */char history_expansion_char = '!';/* The character that invokes word substitution if found at the start of   a line.  This is usually `^'. */char history_subst_char = '^';/* During tokenization, if this character is seen as the first character   of a word, then it, and all subsequent characters upto a newline are   ignored.  For a Bourne shell, this should be '#'.  Bash special cases   the interactive comment character to not be a comment delimiter. */char history_comment_char = '\0';/* The list of characters which inhibit the expansion of text if found   immediately following history_expansion_char. */char *history_no_expand_chars = " \t\n\r=";/* If set to a non-zero value, single quotes inhibit history expansion.   The default is 0. */int history_quotes_inhibit_expansion = 0;/* If set, this points to a function that is called to verify that a   particular history expansion should be performed. */Function *history_inhibit_expansion_function;/* **************************************************************** *//*								    *//*			History Expansion			    *//*								    *//* **************************************************************** *//* Hairy history expansion on text, not tokens.  This is of general   use, and thus belongs in this library. *//* The last string searched for by a !?string? search. */static char *search_string;/* The last string matched by a !?string? search. */static char *search_match;/* Return the event specified at TEXT + OFFSET modifying OFFSET to   point to after the event specifier.  Just a pointer to the history   line is returned; NULL is returned in the event of a bad specifier.   You pass STRING with *INDEX equal to the history_expansion_char that   begins this specification.   DELIMITING_QUOTE is a character that is allowed to end the string   specification for what to search for in addition to the normal   characters `:', ` ', `\t', `\n', and sometimes `?'.   So you might call this function like:   line = get_history_event ("!echo:p", &index, 0);  */char *get_history_event (string, caller_index, delimiting_quote)     char *string;     int *caller_index;     int delimiting_quote;{  register int i;  register char c;  HIST_ENTRY *entry;  int which, sign, local_index, substring_okay;  Function *search_func;  char *temp;  /* The event can be specified in a number of ways.     !!   the previous command     !n   command line N     !-n  current command-line minus N     !str the most recent command starting with STR     !?str[?]	  the most recent command containing STR     All values N are determined via HISTORY_BASE. */  i = *caller_index;  if (string[i] != history_expansion_char)    return ((char *)NULL);  /* Move on to the specification. */  i++;  sign = 1;  substring_okay = 0;#define RETURN_ENTRY(e, w) \	return ((e = history_get (w)) ? e->line : (char *)NULL)  /* Handle !! case. */  if (string[i] == history_expansion_char)    {      i++;      which = history_base + (history_length - 1);      *caller_index = i;      RETURN_ENTRY (entry, which);    }  /* Hack case of numeric line specification. */  if (string[i] == '-')    {      sign = -1;      i++;    }  if (_rl_digit_p (string[i]))    {      /* Get the extent of the digits and compute the value. */      for (which = 0; _rl_digit_p (string[i]); i++)	which = (which * 10) + _rl_digit_value (string[i]);      *caller_index = i;      if (sign < 0)	which = (history_length + history_base) - which;      RETURN_ENTRY (entry, which);    }  /* This must be something to search for.  If the spec begins with     a '?', then the string may be anywhere on the line.  Otherwise,     the string must be found at the start of a line. */  if (string[i] == '?')    {      substring_okay++;      i++;    }  /* Only a closing `?' or a newline delimit a substring search string. */  for (local_index = i; c = string[i]; i++)    if ((!substring_okay && (whitespace (c) || c == ':' ||	(history_search_delimiter_chars && member (c, history_search_delimiter_chars)) ||	string[i] == delimiting_quote)) ||	string[i] == '\n' ||	(substring_okay && string[i] == '?'))      break;  which = i - local_index;  temp = xmalloc (1 + which);  if (which)    strncpy (temp, string + local_index, which);  temp[which] = '\0';  if (substring_okay && string[i] == '?')    i++;  *caller_index = i;#define FAIL_SEARCH() \  do { \    history_offset = history_length; free (temp) ; return (char *)NULL; \  } while (0)  /* If there is no search string, try to use the previous search string,     if one exists.  If not, fail immediately. */  if (*temp == '\0' && substring_okay)    {      if (search_string)        {          free (temp);          temp = savestring (search_string);        }      else        FAIL_SEARCH ();    }  search_func = substring_okay ? history_search : history_search_prefix;  while (1)    {      local_index = (*search_func) (temp, -1);      if (local_index < 0)	FAIL_SEARCH ();      if (local_index == 0 || substring_okay)	{	  entry = current_history ();	  history_offset = history_length;		  /* If this was a substring search, then remember the	     string that we matched for word substitution. */	  if (substring_okay)	    {	      FREE (search_string);	      search_string = temp;	      FREE (search_match);	      search_match = history_find_word (entry->line, local_index);	    }	  else	    free (temp);	  return (entry->line);	}      if (history_offset)	history_offset--;      else	FAIL_SEARCH ();    }#undef FAIL_SEARCH#undef RETURN_ENTRY}/* Function for extracting single-quoted strings.  Used for inhibiting   history expansion within single quotes. *//* 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   to the closing single quote. */static voidhist_string_extract_single_quoted (string, sindex)     char *string;     int *sindex;{  register int i;  for (i = *sindex; string[i] && string[i] != '\''; i++)    ;  *sindex = i;}static char *quote_breaks (s)     char *s;{  register char *p, *r;  char *ret;  int len = 3;  for (p = s; p && *p; p++, len++)    {      if (*p == '\'')	len += 3;      else if (whitespace (*p) || *p == '\n')	len += 2;    }  r = ret = xmalloc (len);  *r++ = '\'';  for (p = s; p && *p; )    {      if (*p == '\'')	{	  *r++ = '\'';	  *r++ = '\\';	  *r++ = '\'';	  *r++ = '\'';	  p++;	}      else if (whitespace (*p) || *p == '\n')	{	  *r++ = '\'';	  *r++ = *p++;	  *r++ = '\'';	}      else	*r++ = *p++;    }  *r++ = '\'';  *r = '\0';  return ret;}static char *hist_error(s, start, current, errtype)      char *s;      int start, current, errtype;{  char *temp, *emsg;  int ll, elen, len;  ll = current - start;  switch (errtype)    {    case EVENT_NOT_FOUND:      emsg = "event not found";      elen = 15;      break;    case BAD_WORD_SPEC:      emsg = "bad word specifier";      elen = 18;      break;    case SUBST_FAILED:      emsg = "substitution failed";      elen = 19;      break;    case BAD_MODIFIER:      emsg = "unrecognized history modifier";      elen = 29;      break;    case NO_PREV_SUBST:      emsg = "no previous substitution";      elen = 24;      break;    default:      emsg = "unknown expansion error";      elen = 23;      break;    }  len = ll + elen + 3;   temp = xmalloc (len);  strncpy (temp, s + start, ll);  strlcat (temp, ": ", len);  strlcat (temp, emsg, len);  return (temp);}/* Get a history substitution string from STR starting at *IPTR   and return it.  The length is returned in LENPTR.   A backslash can quote the delimiter.  If the string is the   empty string, the previous pattern is used.  If there is   no previous pattern for the lhs, the last history search   string is used.   If IS_RHS is 1, we ignore empty strings and set the pattern   to "" anyway.  subst_lhs is not changed if the lhs is empty;   subst_rhs is allowed to be set to the empty string. */static char *get_subst_pattern (str, iptr, delimiter, is_rhs, lenptr)     char *str;     int *iptr, delimiter, is_rhs, *lenptr;{  register int si, i, j, k;  char *s = (char *) NULL;  i = *iptr;  for (si = i; str[si] && str[si] != delimiter; si++)    if (str[si] == '\\' && str[si + 1] == delimiter)      si++;  if (si > i || is_rhs)    {      s = xmalloc (si - i + 1);      for (j = 0, k = i; k < si; j++, k++)	{	  /* Remove a backslash quoting the search string delimiter. */	  if (str[k] == '\\' && str[k + 1] == delimiter)	    k++;	  s[j] = str[k];	}      s[j] = '\0';      if (lenptr)	*lenptr = j;    }  i = si;  if (str[i])    i++;  *iptr = i;  return s;}static voidpostproc_subst_rhs (){  char *new;  int i, j, new_size;  new = xmalloc (new_size = subst_rhs_len + subst_lhs_len);  for (i = j = 0; i < subst_rhs_len; i++)    {      if (subst_rhs[i] == '&')	{	  if (j + subst_lhs_len >= new_size)	    new = xrealloc (new, (new_size = new_size * 2 + subst_lhs_len));	  strlcpy (new + j, subst_lhs, new_size - j);	  j += subst_lhs_len;	}      else	{	  /* a single backslash protects the `&' from lhs interpolation */	  if (subst_rhs[i] == '\\' && subst_rhs[i + 1] == '&')	    i++;	  if (j >= new_size)	    new = xrealloc (new, new_size *= 2);	  new[j++] = subst_rhs[i];	}    }  new[j] = '\0';  free (subst_rhs);  subst_rhs = new;  subst_rhs_len = j;}/* Expand the bulk of a history specifier starting at STRING[START].   Returns 0 if everything is OK, -1 if an error occurred, and 1   if the `p' modifier was supplied and the caller should just print   the returned string.  Returns the new index into string in   *END_INDEX_PTR, and the expanded specifier in *RET_STRING. */static inthistory_expand_internal (string, start, end_index_ptr, ret_string, current_line)     char *string;     int start, *end_index_ptr;     char **ret_string;     char *current_line;	/* for !# */{  int i, n, starting_index;  int substitute_globally, want_quotes, print_only;  char *event, *temp, *result, *tstr, *t, c, *word_spec;  int result_len;  result = xmalloc (result_len = 128);  i = start;  /* If it is followed by something that starts a word specifier,     then !! is implied as the event specifier. */  if (member (string[i + 1], ":$*%^"))    {      char fake_s[3];      int fake_i = 0;      i++;      fake_s[0] = fake_s[1] = history_expansion_char;      fake_s[2] = '\0';      event = get_history_event (fake_s, &fake_i, 0);    }  else if (string[i + 1] == '#')    {      i += 2;      event = current_line;    }  else    {      int quoted_search_delimiter = 0;      /* If the character before this `!' is a double or single	 quote, then this expansion takes place inside of the	 quoted string.  If we have to search for some text ("!foo"),	 allow the delimiter to end the search string. */      if (i && (string[i - 1] == '\'' || string[i - 1] == '"'))	quoted_search_delimiter = string[i - 1];      event = get_history_event (string, &i, quoted_search_delimiter);    }	    if (event == 0)    {      *ret_string = hist_error (string, start, i, EVENT_NOT_FOUND);      free (result);      return (-1);    }  /* If a word specifier is found, then do what that requires. */  starting_index = i;  word_spec = get_history_word_specifier (string, event, &i);  /* There is no such thing as a `malformed word specifier'.  However,     it is possible for a specifier that has no match.  In that case,     we complain. */  if (word_spec == (char *)&error_pointer)    {      *ret_string = hist_error (string, starting_index, i, BAD_WORD_SPEC);      free (result);      return (-1);    }  /* If no word specifier, than the thing of interest was the event. */  temp = word_spec ? savestring (word_spec) : savestring (event);  FREE (word_spec);  /* Perhaps there are other modifiers involved.  Do what they say. */  want_quotes = substitute_globally = print_only = 0;  starting_index = i;  while (string[i] == ':')    {      c = string[i + 1];      if (c == 'g')	{	  substitute_globally = 1;	  i++;	  c = string[i + 1];	}      switch (c)	{	default:	  *ret_string = hist_error (string, i+1, i+2, BAD_MODIFIER);	  free (result);	  free (temp);	  return -1;	case 'q':	  want_quotes = 'q';	  break;	case 'x':	  want_quotes = 'x';	  break;	  /* :p means make this the last executed line.  So we	     return an error state after adding this line to the	     history. */	case 'p':	  print_only++;	  break;	  /* :t discards all but the last part of the pathname. */	case 't':	  tstr = strrchr (temp, '/');	  if (tstr)	    {	      tstr++;	      t = savestring (tstr);	      free (temp);	      temp = t;	    }	  break;	  /* :h discards the last part of a pathname. */	case 'h':	  tstr = strrchr (temp, '/');	  if (tstr)	    *tstr = '\0';	  break;	  /* :r discards the suffix. */	case 'r':	  tstr = strrchr (temp, '.');	  if (tstr)	    *tstr = '\0';	  break;	  /* :e discards everything but the suffix. */	case 'e':	  tstr = strrchr (temp, '.');	  if (tstr)	    {	      t = savestring (tstr);	      free (temp);	      temp = t;	    }	  break;	/* :s/this/that substitutes `that' for the first	   occurrence of `this'.  :gs/this/that substitutes `that'	   for each occurrence of `this'.  :& repeats the last	   substitution.  :g& repeats the last substitution	   globally. */	case '&':	case 's':	  {	    char *new_event, *t;	    int delimiter, failed, si, l_temp;	    if (c == 's')	      {		if (i + 2 < (int)strlen (string))		  delimiter = string[i + 2];		else		  break;	/* no search delimiter */		i += 3;		t = get_subst_pattern (string, &i, delimiter, 0, &subst_lhs_len);		/* An empty substitution lhs with no previous substitution		   uses the last search string as the lhs. */		if (t)		  {		    FREE (subst_lhs);		    subst_lhs = t;		  }		else if (!subst_lhs)		  {		    if (search_string && *search_string)		      {			subst_lhs = savestring (search_string);			subst_lhs_len = strlen (subst_lhs);		      }		    else		      {			subst_lhs = (char *) NULL;			subst_lhs_len = 0;		      }		  }		FREE (subst_rhs);		subst_rhs = get_subst_pattern (string, &i, delimiter, 1, &subst_rhs_len);		/* If `&' appears in the rhs, it's supposed to be replaced		   with the lhs. */		if (member ('&', subst_rhs))		  postproc_subst_rhs ();	      }	    else	      i += 2;	    /* If there is no lhs, the substitution can't succeed. */	    if (subst_lhs_len == 0)	      {		*ret_string = hist_error (string, starting_index, i, NO_PREV_SUBST);		free (result);		free (temp);		return -1;	      }	    l_temp = strlen (temp);	    /* Ignore impossible cases. */	    if (subst_lhs_len > l_temp)	      {		*ret_string = hist_error (string, starting_index, i, SUBST_FAILED);		free (result);		free (temp);		return (-1);	      }	    /* Find the first occurrence of THIS in TEMP. */	    si = 0;	    for (failed = 1; (si + subst_lhs_len) <= l_temp; si++)	      if (STREQN (temp+si, subst_lhs, subst_lhs_len))		{		  int len = subst_rhs_len - subst_lhs_len + l_temp;		  new_event = xmalloc (1 + len);		  strncpy (new_event, temp, si);		  strncpy (new_event + si, subst_rhs, subst_rhs_len);		  strncpy (new_event + si + subst_rhs_len,			   temp + si + subst_lhs_len,			   l_temp - (si + subst_lhs_len));		  new_event[len] = '\0';		  free (temp);		  temp = new_event;		  failed = 0;		  if (substitute_globally)		    {		      si += subst_rhs_len;		      l_temp = strlen (temp);		      substitute_globally++;		      continue;		    }		  else		    break;		}	    if (substitute_globally > 1)	      {		substitute_globally = 0;		continue;	/* don't want to increment i */	      }	    if (failed == 0)	      continue;		/* don't want to increment i */	    *ret_string = hist_error (string, starting_index, i, SUBST_FAILED);	    free (result);	    free (temp);	    return (-1);	  }	}      i += 2;    }  /* Done with modfiers. */  /* Believe it or not, we have to back the pointer up by one. */  --i;  if (want_quotes)    {      char *x;      if (want_quotes == 'q')	x = single_quote (temp);      else if (want_quotes == 'x')	x = quote_breaks (temp);      else	x = savestring (temp);      free (temp);      temp = x;    }  n = strlen (temp);  if (n >= result_len)    result = xrealloc (result, n + 2);  strlcpy (result, temp, n + 2);  free (temp);  *end_index_ptr = i;  *ret_string = result;  return (print_only);}/* Expand the string STRING, placing the result into OUTPUT, a pointer   to a string.  Returns:  -1) If there was an error in expansion.   0) If no expansions took place (or, if the only change in      the text was the de-slashifying of the history expansion      character)   1) If expansions did take place   2) If the `p' modifier was given and the caller should print the result  If an error ocurred in expansion, then OUTPUT contains a descriptive  error message. */#define ADD_STRING(s) \	do \	  { \	    int sl = strlen (s); \	    j += sl; \	    if (j >= result_len) \	      { \		while (j >= result_len) \		  result_len += 128; \		result = xrealloc (result, result_len); \	      } \	    strlcpy (result + j - sl, s, result_len - j + sl); \	  } \	while (0)#define ADD_CHAR(c) \	do \	  { \	    if (j >= result_len - 1) \	      result = xrealloc (result, result_len += 64); \	    result[j++] = c; \	    result[j] = '\0'; \	  } \	while (0)inthistory_expand (hstring, output)     char *hstring;     char **output;{  register int j;  int i, r, l, passc, cc, modified, eindex, only_printing;  char *string;  /* The output string, and its length. */  int result_len;  char *result;  /* Used when adding the string. */  char *temp;  /* Setting the history expansion character to 0 inhibits all     history expansion. */  if (history_expansion_char == 0)    {      *output = savestring (hstring);      return (0);    }      /* Prepare the buffer for printing error messages. */  result = xmalloc (result_len = 256);  result[0] = '\0';  only_printing = modified = 0;  l = strlen (hstring);  /* Grovel the string.  Only backslash and single quotes can quote the     history escape character.  We also handle arg specifiers. */  /* Before we grovel forever, see if the history_expansion_char appears     anywhere within the text. */  /* The quick substitution character is a history expansion all right.  That     is to say, "^this^that^" is equivalent to "!!:s^this^that^", and in fact,     that is the substitution that we do. */  if (hstring[0] == history_subst_char)    {      string = xmalloc (l + 5);      string[0] = string[1] = history_expansion_char;      string[2] = ':';      string[3] = 's';      strlcpy (string + 4, hstring, l - 4);      l += 4;    }  else    {      string = hstring;      /* If not quick substitution, still maybe have to do expansion. */      /* `!' followed by one of the characters in history_no_expand_chars	 is NOT an expansion. */      for (i = 0; string[i]; i++)	{	  cc = string[i + 1];	  /* The history_comment_char, if set, appearing that the beginning	     of a word signifies that the rest of the line should not have	     history expansion performed on it.	     Skip the rest of the line and break out of the loop. */	  if (history_comment_char && string[i] == history_comment_char &&	      (i == 0 || member (string[i - 1], HISTORY_WORD_DELIMITERS)))	    {	      while (string[i])		i++;	      break;	    }	  else if (string[i] == history_expansion_char)	    {	      if (!cc || member (cc, history_no_expand_chars))		continue;	      /* If the calling application has set		 history_inhibit_expansion_function to a function that checks		 for special cases that should not be history expanded,		 call the function and skip the expansion if it returns a		 non-zero value. */	      else if (history_inhibit_expansion_function &&			(*history_inhibit_expansion_function) (string, i))		continue;	      else		break;	    }	  /* XXX - at some point, might want to extend this to handle		   double quotes as well. */	  else if (history_quotes_inhibit_expansion && string[i] == '\'')	    {	      /* If this is bash, single quotes inhibit history expansion. */	      i++;	      hist_string_extract_single_quoted (string, &i);	    }	  else if (history_quotes_inhibit_expansion && string[i] == '\\')	    {	      /* If this is bash, allow backslashes to quote single		 quotes and the history expansion character. */	      if (cc == '\'' || cc == history_expansion_char)		i++;	    }	}	        if (string[i] != history_expansion_char)	{	  free (result);	  *output = savestring (string);	  return (0);	}    }  /* Extract and perform the substitution. */  for (passc = i = j = 0; i < l; i++)    {      int tchar = string[i];      if (passc)	{	  passc = 0;	  ADD_CHAR (tchar);	  continue;	}      if (tchar == history_expansion_char)	tchar = -3;      else if (tchar == history_comment_char)	tchar = -2;      switch (tchar)	{	default:	  ADD_CHAR (string[i]);	  break;	case '\\':	  passc++;	  ADD_CHAR (tchar);	  break;	case '\'':	  {	    /* If history_quotes_inhibit_expansion is set, single quotes	       inhibit history expansion. */	    if (history_quotes_inhibit_expansion)	      {		int quote, slen;		quote = i++;		hist_string_extract_single_quoted (string, &i);		slen = i - quote + 2;		temp = xmalloc (slen);		strncpy (temp, string + quote, slen);		temp[slen - 1] = '\0';		ADD_STRING (temp);		free (temp);	      }	    else	      ADD_CHAR (string[i]);	    break;	  }	case -2:		/* history_comment_char */	  if (i == 0 || member (string[i - 1], HISTORY_WORD_DELIMITERS))	    {	      temp = xmalloc (l - i + 1);	      strlcpy (temp, string + i, l - i + 1);	      ADD_STRING (temp);	      free (temp);	      i = l;	    }	  else	    ADD_CHAR (string[i]);	  break;	case -3:		/* history_expansion_char */	  cc = string[i + 1];	  /* If the history_expansion_char is followed by one of the	     characters in history_no_expand_chars, then it is not a	     candidate for expansion of any kind. */	  if (member (cc, history_no_expand_chars))	    {	      ADD_CHAR (string[i]);	      break;	    }#if defined (NO_BANG_HASH_MODIFIERS)	  /* There is something that is listed as a `word specifier' in csh	     documentation which means `the expanded text to this point'.	     That is not a word specifier, it is an event specifier.  If we	     don't want to allow modifiers with `!#', just stick the current	     output line in again. */	  if (cc == '#')	    {	      if (result)		{		  temp = xmalloc (1 + strlen (result));		  strlcpy (temp, result, 1 + strlen(result));		  ADD_STRING (temp);		  free (temp);		}	      i++;	      break;	    }#endif	  r = history_expand_internal (string, i, &eindex, &temp, result);	  if (r < 0)	    {	      *output = temp;	      free (result);	      if (string != hstring)		free (string);	      return -1;	    }	  else	    {	      if (temp)		{		  modified++;		  if (*temp)		    ADD_STRING (temp);		  free (temp);		}	      only_printing = r == 1;	      i = eindex;	    }	  break;	}    }  *output = result;  if (string != hstring)    free (string);  if (only_printing)    {      add_history (result);      return (2);    }  return (modified != 0);}/* Return a consed string which is the word specified in SPEC, and found   in FROM.  NULL is returned if there is no spec.  The address of   ERROR_POINTER is returned if the word specified cannot be found.   CALLER_INDEX is the offset in SPEC to start looking; it is updated   to point to just after the last character parsed. */static char *get_history_word_specifier (spec, from, caller_index)     char *spec, *from;     int *caller_index;{  register int i = *caller_index;  int first, last;  int expecting_word_spec = 0;  char *result;  /* The range of words to return doesn't exist yet. */  first = last = 0;  result = (char *)NULL;  /* If we found a colon, then this *must* be a word specification.  If     it isn't, then it is an error. */  if (spec[i] == ':')    {      i++;      expecting_word_spec++;    }  /* Handle special cases first. */  /* `%' is the word last searched for. */  if (spec[i] == '%')    {      *caller_index = i + 1;      return (search_match ? savestring (search_match) : savestring (""));    }  /* `*' matches all of the arguments, but not the command. */  if (spec[i] == '*')    {      *caller_index = i + 1;      result = history_arg_extract (1, '$', from);      return (result ? result : savestring (""));    }  /* `$' is last arg. */  if (spec[i] == '$')    {      *caller_index = i + 1;      return (history_arg_extract ('$', '$', from));    }  /* Try to get FIRST and LAST figured out. */  if (spec[i] == '-')    first = 0;  else if (spec[i] == '^')    first = 1;  else if (_rl_digit_p (spec[i]) && expecting_word_spec)    {      for (first = 0; _rl_digit_p (spec[i]); i++)	first = (first * 10) + _rl_digit_value (spec[i]);    }  else    return ((char *)NULL);	/* no valid `first' for word specifier */  if (spec[i] == '^' || spec[i] == '*')    {      last = (spec[i] == '^') ? 1 : '$';	/* x* abbreviates x-$ */      i++;    }  else if (spec[i] != '-')    last = first;  else    {      i++;      if (_rl_digit_p (spec[i]))	{	  for (last = 0; _rl_digit_p (spec[i]); i++)	    last = (last * 10) + _rl_digit_value (spec[i]);	}      else if (spec[i] == '$')	{	  i++;	  last = '$';	}      else if (!spec[i] || spec[i] == ':')  /* could be modifier separator */	last = -1;		/* x- abbreviates x-$ omitting word `$' */    }  *caller_index = i;  if (last >= first || last == '$' || last < 0)    result = history_arg_extract (first, last, from);  return (result ? result : (char *)&error_pointer);}/* Extract the args specified, starting at FIRST, and ending at LAST.   The args are taken from STRING.  If either FIRST or LAST is < 0,   then make that arg count from the right (subtract from the number of   tokens, so that FIRST = -1 means the next to last token on the line).   If LAST is `$' the last arg from STRING is used. */char *history_arg_extract (first, last, string)     int first, last;     char *string;{  register int i, len;  char *result;  int size, offset;  char **list;  /* XXX - think about making history_tokenize return a struct array,     each struct in array being a string and a length to avoid the     calls to strlen below. */  if ((list = history_tokenize (string)) == NULL)    return ((char *)NULL);  for (len = 0; list[len]; len++)    ;  if (last < 0)    last = len + last - 1;  if (first < 0)    first = len + first - 1;  if (last == '$')    last = len - 1;  if (first == '$')    first = len - 1;  last++;  if (first >= len || last > len || first < 0 || last < 0 || first > last)    result = ((char *)NULL);  else    {      for (size = 0, i = first; i < last; i++)	size += strlen (list[i]) + 1;      result = xmalloc (size + 1);      result[0] = '\0';      for (i = first, offset = 0; i < last; i++)	{	  strlcpy (result + offset, list[i], size + 1 - offset);	  offset += strlen (list[i]);	  if (i + 1 < last)	    {      	      result[offset++] = ' ';	      result[offset] = 0;	    }	}    }  for (i = 0; i < len; i++)    free (list[i]);  free (list);  return (result);}#define slashify_in_quotes "\\`\"$"/* Parse STRING into tokens and return an array of strings.  If WIND is   not -1 and INDP is not null, we also want the word surrounding index   WIND.  The position in the returned array of strings is returned in   *INDP. */static char **history_tokenize_internal (string, wind, indp)     char *string;     int wind, *indp;{  char **result;  register int i, start, result_index, size;  int len, delimiter;  /* Get a token, and stuff it into RESULT.  The tokens are split     exactly where the shell would split them. */  for (i = result_index = size = 0, result = (char **)NULL; string[i]; )    {      delimiter = 0;      /* Skip leading whitespace. */      for (; string[i] && whitespace (string[i]); i++)	;      if (string[i] == 0 || string[i] == history_comment_char)	return (result);      start = i;            if (member (string[i], "()\n"))	{	  i++;	  goto got_token;	}      if (member (string[i], "<>;&|$"))	{	  int peek = string[i + 1];	  if (peek == string[i] && peek != '$')	    {	      if (peek == '<' && string[i + 2] == '-')		i++;	      i += 2;	      goto got_token;	    }	  else	    {	      if ((peek == '&' && (string[i] == '>' || string[i] == '<')) ||		  ((peek == '>') && (string[i] == '&')) ||		  ((peek == '(') && (string[i] == '$')))		{		  i += 2;		  goto got_token;		}	    }	  if (string[i] != '$')	    {	      i++;	      goto got_token;	    }	}      /* Get word from string + i; */      if (member (string[i], HISTORY_QUOTE_CHARACTERS))	delimiter = string[i++];      for (; string[i]; i++)	{	  if (string[i] == '\\' && string[i + 1] == '\n')	    {	      i++;	      continue;	    }	  if (string[i] == '\\' && delimiter != '\'' &&	      (delimiter != '"' || member (string[i], slashify_in_quotes)))	    {	      i++;	      continue;	    }	  if (delimiter && string[i] == delimiter)	    {	      delimiter = 0;	      continue;	    }	  if (!delimiter && (member (string[i], HISTORY_WORD_DELIMITERS)))	    break;	  if (!delimiter && member (string[i], HISTORY_QUOTE_CHARACTERS))	    delimiter = string[i];	}    got_token:      /* If we are looking for the word in which the character at a	 particular index falls, remember it. */      if (indp && wind != -1 && wind >= start && wind < i)        *indp = result_index;      len = i - start;      if (result_index + 2 >= size)	result = (char **)xrealloc (result, ((size += 10) * sizeof (char *)));      result[result_index] = xmalloc (1 + len);      strncpy (result[result_index], string + start, len);      result[result_index][len] = '\0';      result[++result_index] = (char *)NULL;    }  return (result);}/* Return an array of tokens, much as the shell might.  The tokens are   parsed out of STRING. */char **history_tokenize (string)     char *string;{  return (history_tokenize_internal (string, -1, (int *)NULL));}/* Find and return the word which contains the character at index IND   in the history line LINE.  Used to save the word matched by the   last history !?string? search. */static char *history_find_word (line, ind)     char *line;     int ind;{  char **words, *s;  int i, wind;  words = history_tokenize_internal (line, ind, &wind);  if (wind == -1)    return ((char *)NULL);  s = words[wind];  for (i = 0; i < wind; i++)    free (words[i]);  for (i = wind + 1; words[i]; i++)    free (words[i]);  free (words);  return s;}