getline.c

BCAST Implementation for NS2

    const struct GlDefSignal *sig = gl_signal_list + i;
    if(gl_trap_signal(gl, sig->signo, sig->flags, sig->after,
		       sig->errno_value))
      return del_GetLine(gl);
  };
/*
 * Allocate an empty table of key bindings.
 */
  gl->bindings = _new_KeyTab();
  if(!gl->bindings)
    return del_GetLine(gl);
/*
 * Define the available actions that can be bound to key sequences.
 */
  for(i=0; i<sizeof(gl_actions)/sizeof(gl_actions[0]); i++) {
    if(_kt_set_action(gl->bindings, gl_actions[i].name, gl_actions[i].fn))
      return del_GetLine(gl);
  };
/*
 * Set up the default bindings.
 */
  if(gl_change_editor(gl, gl->editor))
    return del_GetLine(gl);
/*
 * Allocate termcap buffers.
 */
#ifdef USE_TERMCAP
  gl->tgetent_buf = (char *) malloc(TERMCAP_BUF_SIZE);
  gl->tgetstr_buf = (char *) malloc(TERMCAP_BUF_SIZE);
  if(!gl->tgetent_buf || !gl->tgetstr_buf) {
    fprintf(stderr, "new_GetLine: Insufficient memory for termcap buffers.\n");
    return del_GetLine(gl);
  };
#endif
/*
 * Set up for I/O assuming stdin and stdout.
 */
  if(gl_change_terminal(gl, stdin, stdout, getenv("TERM")))
    return del_GetLine(gl);
/*
 * Create a freelist for use in allocating GlFdNode list nodes.
 */
#ifdef HAVE_SELECT
  gl->fd_node_mem = _new_FreeList("new_GetLine", sizeof(GlFdNode),
				  GLFD_FREELIST_BLOCKING);
  if(!gl->fd_node_mem)
    return del_GetLine(gl);
#endif
/*
 * We are done for now.
 */
  return gl;
}

/*.......................................................................
 * Delete a GetLine object.
 *
 * Input:
 *  gl     GetLine *  The object to be deleted.
 * Output:
 *  return GetLine *  The deleted object (always NULL).
 */
GetLine *del_GetLine(GetLine *gl)
{
  if(gl) {
    gl->glh = _del_GlHistory(gl->glh);
    gl->cpl = del_WordCompletion(gl->cpl);
    gl->ef = del_ExpandFile(gl->ef);
    gl->capmem = _del_StringGroup(gl->capmem);
    if(gl->line)
      free(gl->line);
    if(gl->cutbuf)
      free(gl->cutbuf);
    if(gl->vi.undo.line)
      free(gl->vi.undo.line);
    gl->sig_mem = _del_FreeList(NULL, gl->sig_mem, 1);
    gl->sigs = NULL;       /* Already freed by freeing sig_mem */
    gl->bindings = _del_KeyTab(gl->bindings);
#ifdef USE_TERMCAP
    if(gl->tgetent_buf)
      free(gl->tgetent_buf);
    if(gl->tgetstr_buf)
      free(gl->tgetstr_buf);
#endif
    if(gl->file_fp)
      fclose(gl->file_fp);
    if(gl->term)
      free(gl->term);
#ifdef HAVE_SELECT
    gl->fd_node_mem = _del_FreeList(NULL, gl->fd_node_mem, 1);
#endif
    free(gl);
  };
  return NULL;
}

/*.......................................................................
 * Bind a control or meta character to an action.
 *
 * Input:
 *  gl         GetLine *  The resource object of this program.
 *  binder    KtBinder    The source of the binding.
 *  c             char    The control or meta character.
 *                        If this is '\0', the call is ignored.
 *  action  const char *  The action name to bind the key to.
 * Output:
 *  return         int    0 - OK.
 *                        1 - Error.
 */
static int gl_bind_control_char(GetLine *gl, KtBinder binder, char c,
				const char *action)
{
  char keyseq[2];
/*
 * Quietly reject binding to the NUL control character, since this
 * is an ambiguous prefix of all bindings.
 */
  if(c == '\0')
    return 0;
/*
 * Making sure not to bind characters which aren't either control or
 * meta characters.
 */
  if(IS_CTRL_CHAR(c) || IS_META_CHAR(c)) {
    keyseq[0] = c;
    keyseq[1] = '\0';
  } else {
    return 0;
  };
/*
 * Install the binding.
 */
  return _kt_set_keybinding(gl->bindings, binder, keyseq, action);
}

/*.......................................................................
 * Read a line from the user.
 *
 * Input:
 *  gl       GetLine *  A resource object returned by new_GetLine().
 *  prompt      char *  The prompt to prefix the line with.
 *  start_line  char *  The initial contents of the input line, or NULL
 *                      if it should start out empty.
 *  start_pos    int    If start_line isn't NULL, this specifies the
 *                      index of the character over which the cursor
 *                      should initially be positioned within the line.
 *                      If you just want it to follow the last character
 *                      of the line, send -1.
 * Output:
 *  return      char *  An internal buffer containing the input line, or
 *                      NULL at the end of input. If the line fitted in
 *                      the buffer there will be a '\n' newline character
 *                      before the terminating '\0'. If it was truncated
 *                      there will be no newline character, and the remains
 *                      of the line should be retrieved via further calls
 *                      to this function.
 */
char *gl_get_line(GetLine *gl, const char *prompt,
		  const char *start_line, int start_pos)
{
  int waserr = 0;    /* True if an error occurs */
  gl->is_net = 0;    /* Reset the 'is_net' flag */
  gl->net_may_block = 0;
  gl->net_read_attempt = 0;
  gl->user_event_value = 0;
/*
 * Check the arguments.
 */
  if(!gl || !prompt) {
    fprintf(stderr, "gl_get_line: NULL argument(s).\n");
    return NULL;
  };
/*
 * If this is the first call to this function since new_GetLine(),
 * complete any postponed configuration.
 */
  if(!gl->configured) {
    (void) gl_configure_getline(gl, NULL, NULL, TECLA_CONFIG_FILE);
    gl->configured = 1;
  };
/*
 * If input is temporarily being taken from a file, return lines
 * from the file until the file is exhausted, then revert to
 * the normal input stream.
 */
  if(gl->file_fp) {
    if(fgets(gl->line, gl->linelen, gl->file_fp))
      return gl->line;
    gl_revert_input(gl);
  };
/*
 * Is input coming from a non-interactive source?
 */
  if(!gl->is_term)
    return fgets(gl->line, gl->linelen, gl->input_fp);
/*
 * Record the new prompt and its displayed width.
 */
  gl_replace_prompt(gl, prompt);
/*
 * Before installing our signal handler functions, record the fact
 * that there are no pending signals.
 */
  gl_pending_signal = -1;
/*
 * Temporarily override the signal handlers of the calling program,
 * so that we can intercept signals that would leave the terminal
 * in a bad state.
 */
  waserr = gl_override_signal_handlers(gl);
/*
 * After recording the current terminal settings, switch the terminal
 * into raw input mode.
 */
  waserr = waserr || gl_raw_terminal_mode(gl);
/*
 * Attempt to read the line.
 */
  waserr = waserr || gl_get_input_line(gl, start_line, start_pos, -1);
/*
 * Restore terminal settings.
 */
  gl_restore_terminal_attributes(gl);
/*
 * Restore the signal handlers.
 */
  gl_restore_signal_handlers(gl);
/*
 * Having restored the program terminal and signal environment,
 * re-submit any signals that were received.
 */
  if(gl_pending_signal != -1) {
    raise(gl_pending_signal);
    waserr = 1;
  };
/*
 * If gl_get_input_line() aborted input due to the user asking to
 * temporarily read lines from a file, read the first line from
 * this file.
 */
  if(!waserr && gl->file_fp)
    return gl_get_line(gl, prompt, NULL, 0);
/*
 * Return the new input line.
 */
  return waserr ? NULL : gl->line;
}

/*.......................................................................
 * Record of the signal handlers of the calling program, so that they
 * can be restored later.
 *
 * Input:
 *  gl    GetLine *   The resource object of this library.
 * Output:
 *  return    int     0 - OK.
 *                    1 - Error.
 */
static int gl_override_signal_handlers(GetLine *gl)
{
  GlSignalNode *sig;   /* A node in the list of signals to be caught */
/*
 * Set up our signal handler.
 */
  SigAction act;
  act.sa_handler = gl_signal_handler;
  sigemptyset(&act.sa_mask);
  act.sa_flags = 0;
/*
 * Get the process signal mask so that we can see which signals the
 * calling program currently has blocked, and so that we can restore this
 * mask before returning to the calling program.
 */
  if(sigprocmask(SIG_SETMASK, NULL, &gl->old_signal_set) == -1) {
    fprintf(stderr, "gl_get_line(): sigprocmask error: %s\n", strerror(errno));
    return 1;
  };
/*
 * Form a new process signal mask from the list of signals that we have
 * been asked to trap.
 */
  sigemptyset(&gl->new_signal_set);
  for(sig=gl->sigs; sig; sig=sig->next) {
/*
 * Trap this signal? If it is blocked by the calling program and we
 * haven't been told to unblock it, don't arrange to trap this signal.
 */
    if(sig->flags & GLS_UNBLOCK_SIG ||
       !sigismember(&gl->old_signal_set, sig->signo)) {
      if(sigaddset(&gl->new_signal_set, sig->signo) == -1) {
	fprintf(stderr, "gl_get_line(): sigaddset error: %s\n",
		strerror(errno));
	return 1;
      };
    };
  };
/*
 * Before installing our signal handlers, block all of the signals
 * that we are going to be trapping.
 */
  if(sigprocmask(SIG_BLOCK, &gl->new_signal_set, NULL) == -1) {
    fprintf(stderr, "gl_get_line(): sigprocmask error: %s\n", strerror(errno));
    return 1;
  };
/*
 * Override the actions of the signals that we are trapping.
 */
  for(sig=gl->sigs; sig; sig=sig->next) {
    if(sigismember(&gl->new_signal_set, sig->signo) &&
       sigaction(sig->signo, &act, &sig->original)) {
      fprintf(stderr, "gl_get_line(): sigaction error: %s\n", strerror(errno));
      return 1;
    };
  };
/*
 * Just in case a SIGWINCH signal was sent to the process while our
 * SIGWINCH signal handler wasn't in place, check to see if the terminal
 * size needs updating.
 */
#ifdef USE_SIGWINCH
  if (gl->is_term) {
    if(gl_resize_terminal(gl, 0))
      return 1;
  }
#endif
  return 0;
}

/*.......................................................................
 * Restore the signal handlers of the calling program.
 *
 * Input:
 *  gl     GetLine *  The resource object of this library.
 * Output:
 *  return     int    0 - OK.
 *                    1 - Error.
 */
static int gl_restore_signal_handlers(GetLine *gl)
{
  GlSignalNode *sig;   /* A node in the list of signals to be caught */
/*
 * Restore application signal handlers that were overriden
 * by gl_override_signal_handlers().
 */
  for(sig=gl->sigs; sig; sig=sig->next) {
    if(sigismember(&gl->new_signal_set, sig->signo) &&
       sigaction(sig->signo, &sig->original, NULL)) {
      fprintf(stderr, "gl_get_line(): sigaction error: %s\n", strerror(errno));
      return 1;
    };
  };
/*
 * Restore the original signal mask.
 */
  if(sigprocmask(SIG_SETMASK, &gl->old_signal_set, NULL) == -1) {
    fprintf(stderr, "gl_get_line(): sigprocmask error: %s\n", strerror(errno));
    return 1;
  };
  return 0;
}

/*.......................................................................
 * This signal handler simply records the fact that a given signal was
 * caught in the file-scope gl_pending_signal variable.
 */
static void gl_signal_handler(int signo)
{
  gl_pending_signal = signo;
  siglongjmp(gl_setjmp_buffer, 1);
}

/*.......................................................................