command.c

早期freebsd实现

  /* Check all possibilities in the current command list.  */
  found = 0;
  nfound = 0;
  for (c = list; c; c = c->next)
    {
      if (!strncmp (processed_cmd, c->name, cmd_len))
	{
	  found = c;
	  nfound++;
	  if (c->name[cmd_len] == 0)
	    {
	      nfound = 1;
	      break;
	    }
	}
    }

  /* Report error for undefined command name.  */

  if (nfound != 1)
    {
      if (nfound > 1 && allow_unknown >= 0)
	{
	  ambbuf[0] = 0;
	  for (c = list; c; c = c->next)
	    if (!strncmp (processed_cmd, c->name, cmd_len))
	      {
		if (strlen (ambbuf) + strlen (c->name) + 6 < sizeof ambbuf)
		  {
		    if (strlen (ambbuf))
		      strcat (ambbuf, ", ");
		    strcat (ambbuf, c->name);
		  }
		else
		  {
		    strcat (ambbuf, "..");
		    break;
		  }
	      }
	  error ("Ambiguous %scommand \"%s\": %s.", cmdtype,
		 processed_cmd, ambbuf);
	}
      else if (!allow_unknown)
	error ("Undefined %scommand: \"%s\".", cmdtype, processed_cmd);
      return 0;
    }

  /* Skip whitespace before the argument.  */

  while (*p == ' ' || *p == '\t') p++;
  *line = p;

  if (found->prefixlist && *p)
    {
      c = lookup_cmd (line, *found->prefixlist, found->prefixname,
		      found->allow_unknown);
      if (c)
	return c;
    }

  return found;
}
#endif

/* Helper function for SYMBOL_COMPLETION_FUNCTION.  */

/* Return a vector of char pointers which point to the different
   possible completions in LIST of TEXT.  */

char **
complete_on_cmdlist (list, text)
     struct cmd_list_element *list;
     char *text;
{
  struct cmd_list_element *ptr;
  char **matchlist;
  int sizeof_matchlist;
  int matches;
  int textlen = strlen (text);

  sizeof_matchlist = 10;
  matchlist = (char **) xmalloc (sizeof_matchlist * sizeof (char *));
  matches = 0;

  for (ptr = list; ptr; ptr = ptr->next)
    if (!strncmp (ptr->name, text, textlen)
	&& !ptr->abbrev_flag
	&& (ptr->function.cfunc
	    || ptr->prefixlist))
      {
	if (matches == sizeof_matchlist)
	  {
	    sizeof_matchlist *= 2;
	    matchlist = (char **) xrealloc ((char *)matchlist,
					    (sizeof_matchlist
					     * sizeof (char *)));
	  }

	matchlist[matches] = (char *) 
	  xmalloc (strlen (ptr->name) + 1);
	strcpy (matchlist[matches++], ptr->name);
      }

  if (matches == 0)
    {
      free ((PTR)matchlist);
      matchlist = 0;
    }
  else
    {
      matchlist = (char **) xrealloc ((char *)matchlist, ((matches + 1)
						* sizeof (char *)));
      matchlist[matches] = (char *) 0;
    }

  return matchlist;
}

static int
parse_binary_operation (arg)
     char *arg;
{
  int length;

  if (!arg || !*arg)
    return 1;

  length = strlen (arg);

  while (arg[length - 1] == ' ' || arg[length - 1] == '\t')
    length--;

  if (!strncmp (arg, "on", length)
      || !strncmp (arg, "1", length)
      || !strncmp (arg, "yes", length))
    return 1;
  else
    if (!strncmp (arg, "off", length)
	|| !strncmp (arg, "0", length)
	|| !strncmp (arg, "no", length))
      return 0;
    else 
      {
	error ("\"on\" or \"off\" expected.");
	return 0;
      }
}

/* Do a "set" or "show" command.  ARG is NULL if no argument, or the text
   of the argument, and FROM_TTY is nonzero if this command is being entered
   directly by the user (i.e. these are just like any other
   command).  C is the command list element for the command.  */
void
do_setshow_command (arg, from_tty, c)
     char *arg;
     int from_tty;
     struct cmd_list_element *c;
{
  if (c->type == set_cmd)
    {
      switch (c->var_type)
	{
	case var_string:
	  {
	    char *new;
	    char *p;
	    char *q;
	    int ch;
	    
	    if (arg == NULL)
	      arg = "";
	    new = (char *) xmalloc (strlen (arg) + 2);
	    p = arg; q = new;
	    while ((ch = *p++) != '\000')
	      {
		if (ch == '\\')
		  {
		    /* \ at end of argument is used after spaces
		       so they won't be lost.  */
		    if (*p == 0)
		      break;
		    ch = parse_escape (&p);
		    if (ch == 0)
		      break; /* C loses */
		    else if (ch > 0)
		      *q++ = ch;
		  }
		else
		  *q++ = ch;
	      }
	    if (*(p - 1) != '\\')
	      *q++ = ' ';
	    *q++ = '\0';
	    new = (char *) xrealloc (new, q - new);
	    if (*(char **)c->var != NULL)
	      free (*(char **)c->var);
	    *(char **) c->var = new;
	  }
	  break;
	case var_string_noescape:
	  if (arg == NULL)
	    arg = "";
	  if (*(char **)c->var != NULL)
	    free (*(char **)c->var);
	  *(char **) c->var = savestring (arg, strlen (arg));
	  break;
	case var_filename:
	  if (arg == NULL)
	    error_no_arg ("filename to set it to.");
	  if (*(char **)c->var != NULL)
	    free (*(char **)c->var);
	  *(char **)c->var = tilde_expand (arg);
	  break;
	case var_boolean:
	  *(int *) c->var = parse_binary_operation (arg);
	  break;
	case var_uinteger:
	  if (arg == NULL)
	    error_no_arg ("integer to set it to.");
	  *(int *) c->var = parse_and_eval_address (arg);
	  if (*(int *) c->var == 0)
	    *(int *) c->var = UINT_MAX;
	  break;
	case var_zinteger:
	  if (arg == NULL)
	    error_no_arg ("integer to set it to.");
	  *(int *) c->var = parse_and_eval_address (arg);
	  break;
	default:
	  error ("gdb internal error: bad var_type in do_setshow_command");
	}
    }
  else if (c->type == show_cmd)
    {
      /* Print doc minus "show" at start.  */
      print_doc_line (stdout, c->doc + 5);
      
      fputs_filtered (" is ", stdout);
      wrap_here ("    ");
      switch (c->var_type)
	{
      case var_string:
	{
	  unsigned char *p;
	  fputs_filtered ("\"", stdout);
	  for (p = *(unsigned char **) c->var; *p != '\0'; p++)
	    printchar (*p, stdout, '"');
	  fputs_filtered ("\"", stdout);
	}
	break;
      case var_string_noescape:
      case var_filename:
	fputs_filtered ("\"", stdout);
	fputs_filtered (*(char **) c->var, stdout);
	fputs_filtered ("\"", stdout);
	break;
      case var_boolean:
	fputs_filtered (*(int *) c->var ? "on" : "off", stdout);
	break;
      case var_uinteger:
	if (*(unsigned int *) c->var == UINT_MAX) {
	  fputs_filtered ("unlimited", stdout);
	  break;
	}
	/* else fall through */
      case var_zinteger:
	fprintf_filtered (stdout, "%d", *(unsigned int *) c->var);
	break;
      default:
	error ("gdb internal error: bad var_type in do_setshow_command");
      }
      fputs_filtered (".\n", stdout);
    }
  else
    error ("gdb internal error: bad cmd_type in do_setshow_command");
  (*c->function.sfunc) (NULL, from_tty, c);
}

/* Show all the settings in a list of show commands.  */

void
cmd_show_list (list, from_tty, prefix)
     struct cmd_list_element *list;
     int from_tty;
     char *prefix;
{
  for (; list != NULL; list = list->next) {
    /* If we find a prefix, run its list, prefixing our output by its
       prefix (with "show " skipped).  */
    if (list->prefixlist && !list->abbrev_flag)
      cmd_show_list (*list->prefixlist, from_tty, list->prefixname + 5);
    if (list->type == show_cmd)
      {
	fputs_filtered (prefix, stdout);
	fputs_filtered (list->name, stdout);
	fputs_filtered (":  ", stdout);
	do_setshow_command ((char *)NULL, from_tty, list);
      }
  }
}

/* ARGSUSED */
static void
shell_escape (arg, from_tty)
     char *arg;
     int from_tty;
{
  int rc, status, pid;
  char *p, *user_shell;

  if ((user_shell = (char *) getenv ("SHELL")) == NULL)
    user_shell = "/bin/sh";

  /* Get the name of the shell for arg0 */
  if ((p = strrchr (user_shell, '/')) == NULL)
    p = user_shell;
  else
    p++;			/* Get past '/' */

  if ((pid = fork()) == 0)
    {
      if (!arg)
	execl (user_shell, p, 0);
      else
	execl (user_shell, p, "-c", arg, 0);

      fprintf (stderr, "Exec of shell failed\n");
      exit (0);
    }

  if (pid != -1)
    while ((rc = wait (&status)) != pid && rc != -1)
      ;
  else
    error ("Fork failed");
}

static void
make_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  char *p;

  if (arg == 0)
    p = "make";
  else
    {
      p = xmalloc (sizeof("make ") + strlen(arg));
      strcpy (p, "make ");
      strcpy (p + sizeof("make ")-1, arg);
    }
  
  shell_escape (p, from_tty);
}

static void
show_user_1 (c, stream)
     struct cmd_list_element *c;
     FILE *stream;
{
  register struct command_line *cmdlines;

  cmdlines = c->user_commands;
  if (!cmdlines)
    return;
  fprintf_filtered (stream, "User command %s:\n", c->name);
  while (cmdlines)
    {
      fprintf_filtered (stream, "%s\n", cmdlines->line); 
      cmdlines = cmdlines->next;
    }
  fputs_filtered ("\n", stream);
}

/* ARGSUSED */
static void
show_user (args, from_tty)
     char *args;
     int from_tty;
{
  struct cmd_list_element *c;
  extern struct cmd_list_element *cmdlist;

  if (args)
    {
      c = lookup_cmd (&args, cmdlist, "", 0, 1);
      if (c->class != class_user)
	error ("Not a user command.");
      show_user_1 (c, stdout);
    }
  else
    {
      for (c = cmdlist; c; c = c->next)
	{
	  if (c->class == class_user)
	    show_user_1 (c, stdout);
	}
    }
}

void
_initialize_command ()
{
  add_com ("shell", class_support, shell_escape,
	   "Execute the rest of the line as a shell command.  \n\
With no arguments, run an inferior shell.");

  add_com ("make", class_support, make_command,
	   "Run the ``make'' program using the rest of the line as arguments.");

  add_cmd ("user", no_class, show_user, 
	   "Show definitions of user defined commands.\n\
Argument is the name of the user defined command.\n\
With no argument, show definitions of all user defined commands.", &showlist);
}