readline.c

早期freebsd实现

static sighandler
rl_handle_sigwinch (sig)
     int sig;
{
  char *term;

  term = rl_terminal_name;

  if (readline_echoing_p)
    {
      if (!term)
	term = getenv ("TERM");
      if (!term)
	term = "dumb";
      rl_reset_terminal (term);
#if defined (NOTDEF)
      crlf ();
      rl_forced_update_display ();
#endif /* NOTDEF */
    }

  if (old_sigwinch &&
      old_sigwinch != (SigHandler *)SIG_IGN &&
      old_sigwinch != (SigHandler *)SIG_DFL)
    (*old_sigwinch) (sig);
#if !defined (VOID_SIGHANDLER)
  return (0);
#endif /* VOID_SIGHANDLER */
}
#endif  /* SIGWINCH */

#if defined (HANDLE_SIGNALS)
/* Interrupt handling. */
static SigHandler
  *old_int  = (SigHandler *)NULL,
  *old_tstp = (SigHandler *)NULL,
  *old_ttou = (SigHandler *)NULL,
  *old_ttin = (SigHandler *)NULL,
  *old_cont = (SigHandler *)NULL,
  *old_alrm = (SigHandler *)NULL;

/* Handle an interrupt character. */
static sighandler
rl_signal_handler (sig)
     int sig;
{
#if !defined (HAVE_BSD_SIGNALS)
  /* Since the signal will not be blocked while we are in the signal
     handler, ignore it until rl_clear_signals resets the catcher. */
  if (sig == SIGINT)
    signal (sig, SIG_IGN);
#endif /* !HAVE_BSD_SIGNALS */

  switch (sig)
    {
    case SIGINT:
      free_undo_list ();
      rl_clear_message ();
      rl_init_argument ();

#if defined (SIGTSTP)
    case SIGTSTP:
    case SIGTTOU:
    case SIGTTIN:
#endif /* SIGTSTP */
    case SIGALRM:
      rl_clean_up_for_exit ();
      rl_deprep_terminal ();
      rl_clear_signals ();
      rl_pending_input = 0;

      kill (getpid (), sig);

      SIGNALS_UNBLOCK;

      rl_prep_terminal ();
      rl_set_signals ();
    }

#if !defined (VOID_SIGHANDLER)
  return (0);
#endif /* !VOID_SIGHANDLER */
}

rl_set_signals ()
{
  old_int = (SigHandler *)signal (SIGINT, rl_signal_handler);
  if (old_int == (SigHandler *)SIG_IGN)
    signal (SIGINT, SIG_IGN);

  old_alrm = (SigHandler *)signal (SIGALRM, rl_signal_handler);
  if (old_alrm == (SigHandler *)SIG_IGN)
    signal (SIGALRM, SIG_IGN);

#if defined (SIGTSTP)
  old_tstp = (SigHandler *)signal (SIGTSTP, rl_signal_handler);
  if (old_tstp == (SigHandler *)SIG_IGN)
    signal (SIGTSTP, SIG_IGN);
#endif
#if defined (SIGTTOU)
  old_ttou = (SigHandler *)signal (SIGTTOU, rl_signal_handler);
  old_ttin = (SigHandler *)signal (SIGTTIN, rl_signal_handler);

  if (old_tstp == (SigHandler *)SIG_IGN)
    {
      signal (SIGTTOU, SIG_IGN);
      signal (SIGTTIN, SIG_IGN);
    }
#endif

#if defined (SIGWINCH)
  old_sigwinch = (SigHandler *)signal (SIGWINCH, rl_handle_sigwinch);
#endif
}

rl_clear_signals ()
{
  signal (SIGINT, old_int);
  signal (SIGALRM, old_alrm);

#if defined (SIGTSTP)
  signal (SIGTSTP, old_tstp);
#endif

#if defined (SIGTTOU)
  signal (SIGTTOU, old_ttou);
  signal (SIGTTIN, old_ttin);
#endif

#if defined (SIGWINCH)
      signal (SIGWINCH, old_sigwinch);
#endif
}
#endif  /* HANDLE_SIGNALS */


/* **************************************************************** */
/*								    */
/*			Character Input Buffering       	    */
/*								    */
/* **************************************************************** */

#if defined (USE_XON_XOFF)
/* If the terminal was in xoff state when we got to it, then xon_char
   contains the character that is supposed to start it again. */
static int xon_char, xoff_state;
#endif /* USE_XON_XOFF */

static int pop_index = 0, push_index = 0, ibuffer_len = 511;
static unsigned char ibuffer[512];

/* Non-null means it is a pointer to a function to run while waiting for
   character input. */
Function *rl_event_hook = (Function *)NULL;

#define any_typein (push_index != pop_index)

/* Add KEY to the buffer of characters to be read. */
rl_stuff_char (key)
     int key;
{
  if (key == EOF)
    {
      key = NEWLINE;
      rl_pending_input = EOF;
    }
  ibuffer[push_index++] = key;
  if (push_index >= ibuffer_len)
    push_index = 0;
}

/* Return the amount of space available in the
   buffer for stuffing characters. */
int
ibuffer_space ()
{
  if (pop_index > push_index)
    return (pop_index - push_index);
  else
    return (ibuffer_len - (push_index - pop_index));
}

/* Get a key from the buffer of characters to be read.
   Return the key in KEY.
   Result is KEY if there was a key, or 0 if there wasn't. */
int
rl_get_char (key)
     int *key;
{
  if (push_index == pop_index)
    return (0);

  *key = ibuffer[pop_index++];

  if (pop_index >= ibuffer_len)
    pop_index = 0;

  return (1);
}

/* Stuff KEY into the *front* of the input buffer.
   Returns non-zero if successful, zero if there is
   no space left in the buffer. */
int
rl_unget_char (key)
     int key;
{
  if (ibuffer_space ())
    {
      pop_index--;
      if (pop_index < 0)
	pop_index = ibuffer_len - 1;
      ibuffer[pop_index] = key;
      return (1);
    }
  return (0);
}

/* If a character is available to be read, then read it
   and stuff it into IBUFFER.  Otherwise, just return. */
rl_gather_tyi ()
{
#ifdef __GO32__
  char input;
  if (isatty(0))
  {
    int i = rl_getc();
    if (i != EOF)
      rl_stuff_char(i);
  }
  else
    if (kbhit() && ibuffer_space())
      rl_stuff_char(getkey());
#else
  int tty = fileno (in_stream);
  register int tem, result = -1;
  long chars_avail;
  char input;

#if defined (FIONREAD)
  result = ioctl (tty, FIONREAD, &chars_avail);
#endif

  if (result == -1)
    {
      int flags;

      flags = fcntl (tty, F_GETFL, 0);

      fcntl (tty, F_SETFL, (flags | O_NDELAY));
      chars_avail = read (tty, &input, 1);

      fcntl (tty, F_SETFL, flags);
      if (chars_avail == -1 && errno == EAGAIN)
	return;
    }

  /* If there's nothing available, don't waste time trying to read
     something. */
  if (chars_avail == 0)
    return;

  tem = ibuffer_space ();

  if (chars_avail > tem)
    chars_avail = tem;

  /* One cannot read all of the available input.  I can only read a single
     character at a time, or else programs which require input can be
     thwarted.  If the buffer is larger than one character, I lose.
     Damn! */
  if (tem < ibuffer_len)
    chars_avail = 0;

  if (result != -1)
    {
      while (chars_avail--)
	rl_stuff_char (rl_getc (in_stream));
    }
  else
    {
      if (chars_avail)
	rl_stuff_char (input);
    }
#endif /* def __GO32__/else */
}

static int next_macro_key ();
/* Read a key, including pending input. */
int
rl_read_key ()
{
  int c;

  rl_key_sequence_length++;

  if (rl_pending_input)
    {
      c = rl_pending_input;
      rl_pending_input = 0;
    }
  else
    {
      /* If input is coming from a macro, then use that. */
      if (c = next_macro_key ())
	return (c);

      /* If the user has an event function, then call it periodically. */
      if (rl_event_hook)
	{
	  while (rl_event_hook && !rl_get_char (&c))
	    {
	      (*rl_event_hook) ();
	      rl_gather_tyi ();
	    }
	}
      else
	{
	  if (!rl_get_char (&c))
	    c = rl_getc (in_stream);
	}
    }

  return (c);
}

/* I'm beginning to hate the declaration rules for various compilers. */
static void add_macro_char (), with_macro_input ();

/* Do the command associated with KEY in MAP.
   If the associated command is really a keymap, then read
   another key, and dispatch into that map. */
rl_dispatch (key, map)
     register int key;
     Keymap map;
{

  if (defining_kbd_macro)
    add_macro_char (key);

  if (key > 127 && key < 256)
    {
      if (map[ESC].type == ISKMAP)
	{
	  map = (Keymap)map[ESC].function;
	  key -= 128;
	  rl_dispatch (key, map);
	}
      else
	ding ();
      return;
    }

  switch (map[key].type)
    {
    case ISFUNC:
      {
	Function *func = map[key].function;

	if (func != (Function *)NULL)
	  {
	    /* Special case rl_do_lowercase_version (). */
	    if (func == rl_do_lowercase_version)
	      {
		rl_dispatch (to_lower (key), map);
		return;
	      }

	    (*map[key].function)(rl_numeric_arg * rl_arg_sign, key);

	    /* If we have input pending, then the last command was a prefix
	       command.  Don't change the state of rl_last_func.  Otherwise,
	       remember the last command executed in this variable. */
	    if (!rl_pending_input)
	      rl_last_func = map[key].function;
	  }
	else
	  {
	    rl_abort ();
	    return;
	  }
      }
      break;

    case ISKMAP:
      if (map[key].function != (Function *)NULL)
	{
	  int newkey;

	  rl_key_sequence_length++;
	  newkey = rl_read_key ();
	  rl_dispatch (newkey, (Keymap)map[key].function);
	}
      else
	{
	  rl_abort ();
	  return;
	}
      break;

    case ISMACR:
      if (map[key].function != (Function *)NULL)
	{
	  char *macro;

	  macro = savestring ((char *)map[key].function);
	  with_macro_input (macro);
	  return;
	}
      break;
    }
}


/* **************************************************************** */
/*								    */
/*			Hacking Keyboard Macros 		    */
/*								    */
/* **************************************************************** */

/* The currently executing macro string.  If this is non-zero,
   then it is a malloc ()'ed string where input is coming from. */
static char *executing_macro = (char *)NULL;

/* The offset in the above string to the next character to be read. */
static int executing_macro_index = 0;

/* The current macro string being built.  Characters get stuffed
   in here by add_macro_char (). */
static char *current_macro = (char *)NULL;

/* The size of the buffer allocated to current_macro. */
static int current_macro_size = 0;

/* The index at which characters are being added to current_macro. */
static int current_macro_index = 0;

/* A structure used to save nested macro strings.
   It is a linked list of string/index for each saved macro. */
struct saved_macro {
  struct saved_macro *next;
  char *string;
  int index;
};

/* The list of saved macros. */
struct saved_macro *macro_list = (struct saved_macro *)NULL;

/* Forward declarations of static functions.  Thank you C. */
static void push_executing_macro (), pop_executing_macro ();

/* This one has to be declared earlier in the file. */
/* static void add_macro_char (); */

/* Set up to read subsequent input from STRING.
   STRING is free ()'ed when we are done with it. */
static void
with_macro_input (string)
     char *string;
{
  push_executing_macro ();
  executing_macro = string;
  executing_macro_index = 0;
}

/* Return the next character available from a macro, or 0 if
   there are no macro characters. */
static int
next_macro_key ()
{
  if (!executing_macro)
    return (0);

  if (!executing_macro[executing_macro_index])
    {
      pop_executing_macro ();
      return (next_macro_key ());
    }

  return (executing_macro[executing_macro_index++]);
}

/* Save the currently executing macro on a stack of saved macros. */
static void
push_executing_macro ()
{
  struct saved_macro *saver;

  saver = (struct saved_macro *)xmalloc (sizeof (struct saved_macro));
  saver->next = macro_list;
  saver->index = executing_macro_index;
  saver->string = executing_macro;

  macro_list = saver;
}

/* Discard the current macro, replacing it with the one
   on the top of the stack of saved macros. */
static void
pop_executing_macro ()
{
  if (executing_macro)
    free (executing_macro);

  executing_macro = (char *)NULL;
  executing_macro_index = 0;

  if (macro_list)
    {
      struct saved_macro *disposer = macro_list;
      executing_macro = macro_list->string;
      executing_macro_index = macro_list->index;
      macro_list = macro_list->next;
      free (disposer);
    }
}

/* Add a character to the macro being built. */
static void
add_macro_char (c)
     int c;
{
  if (current_macro_index + 1 >= current_macro_size)
    {
      if (!current_macro)
	current_macro = (char *)xmalloc (current_macro_size = 25);
      else
	current_macro =
	  (char *)xrealloc (current_macro, current_macro_size += 25);
    }

  current_macro[current_macro_index++] = c;
  current_macro[current_macro_index] = '\0';
}