history.c

早期freebsd实现

		    {
		      i++;
		      substitute_globally = 1;
		      goto substitute;
		    }
		  else
		    
		case 's':
		  substitute:
		  {
		    char *this, *that, *new_event;
		    int delimiter = 0;
		    int si, l_this, l_that, l_temp = strlen (temp);

		    if (i + 2 < strlen (string))
		      delimiter = string[i + 2];

		    if (!delimiter)
		      break;

		    i += 3;

		    /* Get THIS. */
		    for (si = i; string[si] && string[si] != delimiter; si++);
		    l_this = (si - i);
		    this = (char *)alloca (1 + l_this);
		    strncpy (this, string + i, l_this);
		    this[l_this] = '\0';

		    i = si;
		    if (string[si])
		      i++;

		    /* Get THAT. */
		    for (si = i; string[si] && string[si] != delimiter; si++);
		    l_that = (si - i);
		    that = (char *)alloca (1 + l_that);
		    strncpy (that, string + i, l_that);
		    that[l_that] = '\0';

		    i = si;
		    if (string[si]) i++;

		    /* Ignore impossible cases. */
		    if (l_this > l_temp)
		      goto cant_substitute;

		    /* Find the first occurrence of THIS in TEMP. */
		    si = 0;
		    for (; (si + l_this) <= l_temp; si++)
		      if (strncmp (temp + si, this, l_this) == 0)
			{
			  new_event =
			    (char *)alloca (1 + (l_that - l_this) + l_temp);
			  strncpy (new_event, temp, si);
			  strncpy (new_event + si, that, l_that);
			  strncpy (new_event + si + l_that,
				   temp + si + l_this,
				   l_temp - (si + l_this));
			  new_event[(l_that - l_this) + l_temp] = '\0';
			  temp = new_event;

			  if (substitute_globally)
			    {
			      si += l_that;
			      l_temp = strlen (temp);
			      substitute_globally++;
			      continue;
			    }

			  goto hack_specials;
			}

		  cant_substitute:

		    if (substitute_globally > 1)
		      {
			substitute_globally = 0;
			goto hack_specials;
		      }

		    goto event_not_found;
		  }

		  /* :# is the line so far.  Note that we have to
		     alloca () it since RESULT could be realloc ()'ed
		     below in add_string. */
		case '#':
		hack_pound_sign:
		  if (result)
		    {
		      temp = (char *)alloca (1 + strlen (result));
		      strcpy (temp, result);
		    }
		  else
		    temp = "";

		next_special:
		  i += 2;
		  goto hack_specials;
		}

	    }
	  /* Believe it or not, we have to back the pointer up by one. */
	  --i;
	  goto add_string;

	  /* A regular character.  Just add it to the output string. */
	default:
	add_char:
	  tt[0] = string[i];
	  temp = tt;
	  goto do_add;

	add_string:
	  modified++;

	do_add:
	  j += strlen (temp);
	  while (j > len)
	    result = (char *)xrealloc (result, (len += 255));

	  strcpy (result + (j - strlen (temp)), temp);
	}
    }

  *output = result;

  if (only_printing)
    {
      add_history (result);
      return (-1);
    }

  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.  -1 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. */
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 *history_arg_extract ();

  /* The range of words to return doesn't exist yet. */
  first = last = 0;

  /* 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;
      if (search_string)
	return (savestring (search_string));
      else
	return (savestring (""));
    }

  /* `*' matches all of the arguments, but not the command. */
  if (spec[i] == '*')
    {
      char *star_result;

      *caller_index = i + 1;
      star_result = history_arg_extract (1, '$', from);

      if (!star_result)
	star_result = savestring ("");

      return (star_result);
    }

  /* `$' is last arg. */
  if (spec[i] == '$')
    {
      *caller_index = i + 1;
      return (history_arg_extract ('$', '$', from));
    }

  /* Try to get FIRST and LAST figured out. */
  if (spec[i] == '-' || spec[i] == '^')
    {
      first = 1;
      goto get_last;
    }

 get_first:
  if (digit (spec[i]) && expecting_word_spec)
    {
      sscanf (spec + i, "%d", &first);
      for (; digit (spec[i]); i++);
    }
  else
    return ((char *)NULL);

 get_last:
  if (spec[i] == '^')
    {
      i++;
      last = 1;
      goto get_args;
    }

  if (spec[i] != '-')
    {
      last = first;
      goto get_args;
    }

  i++;

  if (digit (spec[i]))
    {
      sscanf (spec + i, "%d", &last);
      for (; digit (spec[i]); i++);
    }
  else
    if (spec[i] == '$')
      {
	i++;
	last = '$';
      }

 get_args:
  {
    char *result = (char *)NULL;

    *caller_index = i;

    if (last >= first)
      result = history_arg_extract (first, last, from);

    if (result)
      return (result);
    else
      return ((char *)-1);
  }
}

/* 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). */
char *
history_arg_extract (first, last, string)
     int first, last;
     char *string;
{
  register int i, len;
  char *result = (char *)NULL;
  int size = 0, offset = 0;

  char **history_tokenize (), **list;

  if (!(list = history_tokenize (string)))
    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)
    result = ((char *)NULL);
  else
    {
      for (i = first; i < last; i++)
	{
	  int l = strlen (list[i]);

	  if (!result)
	    result = (char *)xmalloc ((size = (2 + l)));
	  else
	    result = (char *)xrealloc (result, (size += (2 + l)));
	  strcpy (result + offset, list[i]);
	  offset += l;
	  if (i + 1 < last)
	    {
	      strcpy (result + offset, " ");
	      offset++;
	    }
	}
    }

  for (i = 0; i < len; i++)
    free (list[i]);

  free (list);

  return (result);
}

#define slashify_in_quotes "\\`\"$"

/* Return an array of tokens, much as the shell might.  The tokens are
   parsed out of STRING. */
char **
history_tokenize (string)
     char *string;
{
  char **result = (char **)NULL;
  register int i, start, result_index, size;
  int len;

  i = result_index = size = 0;

  /* Get a token, and stuff it into RESULT.  The tokens are split
     exactly where the shell would split them. */
 get_token:

  /* Skip leading whitespace. */
  for (; string[i] && whitespace(string[i]); i++);

  start = i;

  if (!string[i] || string[i] == history_comment_char)
    return (result);

  if (member (string[i], "()\n")) {
    i++;
    goto got_token;
  }

  if (member (string[i], "<>;&|")) {
    int peek = string[i + 1];

    if (peek == string[i]) {
      if (peek ==  '<') {
	if (string[1 + 2] == '-')
	  i++;
	i += 2;
	goto got_token;
      }

      if (member (peek, ">:&|")) {
	i += 2;
	goto got_token;
      }
    } else {
      if ((peek == '&' &&
	  (string[i] == '>' || string[i] == '<')) ||
	  ((peek == '>') &&
	  (string[i] == '&'))) {
	i += 2;
	goto got_token;
      }
    }
    i++;
    goto got_token;
  }

  /* Get word from string + i; */
  {
    int delimiter = 0;

    if (member (string[i], "\"'`"))
      delimiter = string[i++];

    for (;string[i]; i++) {

      if (string[i] == '\\') {

	if (string[i + 1] == '\n') {
	  i++;
	  continue;
	} else {
	  if (delimiter != '\'')
	    if ((delimiter != '"') ||
		(member (string[i], slashify_in_quotes))) {
	      i++;
	      continue;
	    }
	}
      }

      if (delimiter && string[i] == delimiter) {
	delimiter = 0;
	continue;
      }

      if (!delimiter && (member (string[i], " \t\n;&()|<>")))
	goto got_token;

      if (!delimiter && member (string[i], "\"'`")) {
	delimiter = string[i];
	continue;
      }
    }
    got_token:

    len = i - start;
    if (result_index + 2 >= size) {
      if (!size)
	result = (char **)xmalloc ((size = 10) * (sizeof (char *)));
      else
	result =
	  (char **)xrealloc (result, ((size += 10) * (sizeof (char *))));
    }
    result[result_index] = (char *)xmalloc (1 + len);
    strncpy (result[result_index], string + start, len);
    result[result_index][len] = '\0';
    result_index++;
    result[result_index] = (char *)NULL;
  }
  if (string[i])
    goto get_token;

  return (result);
}

#if defined (STATIC_MALLOC)

/* **************************************************************** */
/*								    */
/*			xmalloc and xrealloc ()		     	    */
/*								    */
/* **************************************************************** */

static void memory_error_and_abort ();

static char *
xmalloc (bytes)
     int bytes;
{
  char *temp = (char *)malloc (bytes);

  if (!temp)
    memory_error_and_abort ();
  return (temp);
}

static char *
xrealloc (pointer, bytes)
     char *pointer;
     int bytes;
{
  char *temp;

  if (!pointer)
    temp = (char *)xmalloc (bytes);
  else
    temp = (char *)realloc (pointer, bytes);

  if (!temp)
    memory_error_and_abort ();

  return (temp);
}

static void
memory_error_and_abort ()
{
  fprintf (stderr, "history: Out of virtual memory!\n");
  abort ();
}
#endif /* STATIC_MALLOC */


/* **************************************************************** */
/*								    */
/*				Test Code			    */
/*								    */
/* **************************************************************** */
#ifdef TEST
main ()
{
  char line[1024], *t;
  int done = 0;

  line[0] = 0;

  while (!done)
    {
      fprintf (stdout, "history%% ");
      t = gets (line);

      if (!t)
	strcpy (line, "quit");

      if (line[0])
	{
	  char *expansion;
	  int result;

	  using_history ();

	  result = history_expand (line, &expansion);
	  strcpy (line, expansion);
	  free (expansion);
	  if (result)
	    fprintf (stderr, "%s\n", line);

	  if (result < 0)
	    continue;

	  add_history (line);
	}

      if (strcmp (line, "quit") == 0) done = 1;
      if (strcmp (line, "save") == 0) write_history (0);
      if (strcmp (line, "read") == 0) read_history (0);
      if (strcmp (line, "list") == 0)
	{
	  register HIST_ENTRY **the_list = history_list ();
	  register int i;

	  if (the_list)
	    for (i = 0; the_list[i]; i++)
	      fprintf (stdout, "%d: %s\n", i + history_base, the_list[i]->line);
	}
      if (strncmp (line, "delete", strlen ("delete")) == 0)
	{
	  int which;
	  if ((sscanf (line + strlen ("delete"), "%d", &which)) == 1)
	    {
	      HIST_ENTRY *entry = remove_history (which);
	      if (!entry)
		fprintf (stderr, "No such entry %d\n", which);
	      else
		{
		  free (entry->line);
		  free (entry);
		}
	    }
	  else
	    {
	      fprintf (stderr, "non-numeric arg given to `delete'\n");
	    }
	}
    }
}

#endif				/* TEST */

/*
* Local variables:
* compile-command: "gcc -g -DTEST -o history history.c"
* end:
*/