command.c

早期freebsd实现

		 * Restore the file we were originally viewing.
		 */
		(void) edit(curr_filename, 0);
}

/*
 * Main command processor.
 * Accept and execute commands until a quit command.
 */
	public void
commands()
{
	register int c;
	register int action;
	register char *cbuf;
	int save_search_type;
	char *s;
	char tbuf[2];
	PARG parg;

	search_type = SRCH_FORW;
	scroll = (sc_height + 1) / 2;

	for (;;)
	{
		mca = 0;
		number = 0;
		optchar = '\0';

		/*
		 * See if any signals need processing.
		 */
		if (sigs)
		{
			psignals();
			if (quitting)
				quit(-1);
		}
			
		/*
		 * Display prompt and accept a character.
		 */
		cmd_reset();
		prompt();
		if (sigs)
			continue;
		c = getcc();

	again:
		if (sigs)
			continue;

		/*
		 * If we are in a multicharacter command, call mca_char.
		 * Otherwise we call cmd_decode to determine the
		 * action to be performed.
		 */
		if (mca)
			switch (mca_char(c))
			{
			case MCA_MORE:
				/*
				 * Need another character.
				 */
				c = getcc();
				goto again;
			case MCA_DONE:
				/*
				 * Command has been handled by mca_char.
				 * Start clean with a prompt.
				 */
				continue;
			case NO_MCA:
				/*
				 * Not a multi-char command
				 * (at least, not anymore).
				 */
				break;
			}

		/*
		 * Decode the command character and decide what to do.
		 */
		if (mca)
		{
			/*
			 * We're in a multichar command.
			 * Add the character to the command buffer
			 * and display it on the screen.
			 * If the user backspaces past the start 
			 * of the line, abort the command.
			 */
			if (cmd_char(c) || len_cmdbuf() == 0)
				continue;
			cbuf = get_cmdbuf();
		} else
		{
			/*
			 * Don't use cmd_char if we're starting fresh
			 * at the beginning of a command, because we
			 * don't want to echo the command until we know
			 * it is a multichar command.  We also don't
			 * want erase_char/kill_char to be treated
			 * as line editing characters.
			 */
			tbuf[0] = c;
			tbuf[1] = '\0';
			cbuf = tbuf;
		}
		s = NULL;
		action = cmd_decode(cbuf, &s);
		/*
		 * If an "extra" string was returned,
		 * process it as a string of command characters.
		 */
		if (s != NULL)
			ungetsc(s);
		/*
		 * Clear the cmdbuf string.
		 * (But not if we're in the prefix of a command,
		 * because the partial command string is kept there.)
		 */
		if (action != A_PREFIX)
			cmd_reset();

		switch (action)
		{
		case A_DIGIT:
			/*
			 * First digit of a number.
			 */
			start_mca(A_DIGIT, ":");
			goto again;

		case A_F_WINDOW:
			/*
			 * Forward one window (and set the window size).
			 */
			if (number > 0)
				swindow = number;
			/* FALLTHRU */
		case A_F_SCREEN:
			/*
			 * Forward one screen.
			 */
			if (number <= 0)
				number = swindow;
			cmd_exec();
			forward(number, 0, 1);
			break;

		case A_B_WINDOW:
			/*
			 * Backward one window (and set the window size).
			 */
			if (number > 0)
				swindow = number;
			/* FALLTHRU */
		case A_B_SCREEN:
			/*
			 * Backward one screen.
			 */
			if (number <= 0)
				number = swindow;
			cmd_exec();
			backward(number, 0, 1);
			break;

		case A_F_LINE:
			/*
			 * Forward N (default 1) line.
			 */
			if (number <= 0)
				number = 1;
			cmd_exec();
			forward(number, 0, 0);
			break;

		case A_B_LINE:
			/*
			 * Backward N (default 1) line.
			 */
			if (number <= 0)
				number = 1;
			cmd_exec();
			backward(number, 0, 0);
			break;

		case A_FF_LINE:
			/*
			 * Force forward N (default 1) line.
			 */
			if (number <= 0)
				number = 1;
			cmd_exec();
			forward(number, 1, 0);
			break;

		case A_BF_LINE:
			/*
			 * Force backward N (default 1) line.
			 */
			if (number <= 0)
				number = 1;
			cmd_exec();
			backward(number, 1, 0);
			break;
		
		case A_F_FOREVER:
			/*
			 * Forward forever, ignoring EOF.
			 */
			cmd_exec();
			jump_forw();
			ignore_eoi = 1;
			hit_eof = 0;
			while (sigs == 0)
				forward(1, 0, 0);
			ignore_eoi = 0;
			break;

		case A_F_SCROLL:
			/*
			 * Forward N lines 
			 * (default same as last 'd' or 'u' command).
			 */
			if (number > 0)
				scroll = number;
			cmd_exec();
			forward(scroll, 0, 0);
			break;

		case A_B_SCROLL:
			/*
			 * Forward N lines 
			 * (default same as last 'd' or 'u' command).
			 */
			if (number > 0)
				scroll = number;
			cmd_exec();
			backward(scroll, 0, 0);
			break;

		case A_FREPAINT:
			/*
			 * Flush buffers, then repaint screen.
			 * Don't flush the buffers on a pipe!
			 */
			ch_flush();
			if (!ispipe)
				clr_linenum();
			/* FALLTHRU */
		case A_REPAINT:
			/*
			 * Repaint screen.
			 */
			cmd_exec();
			repaint();
			break;

		case A_GOLINE:
			/*
			 * Go to line N, default beginning of file.
			 */
			if (number <= 0)
				number = 1;
			cmd_exec();
			jump_back(number);
			break;

		case A_PERCENT:
			/*
			 * Go to a specified percentage into the file.
			 */
			if (number < 0)
				number = 0;
			if (number > 100)
				number = 100;
			cmd_exec();
			jump_percent(number);
			break;

		case A_GOEND:
			/*
			 * Go to line N, default end of file.
			 */
			cmd_exec();
			if (number <= 0)
				jump_forw();
			else
				jump_back(number);
			break;

		case A_GOPOS:
			/*
			 * Go to a specified byte position in the file.
			 */
			cmd_exec();
			if (number < 0)
				number = 0;
			jump_line_loc((POSITION)number, jump_sline);
			break;

		case A_STAT:
			/*
			 * Print file name, etc.
			 */
			cmd_exec();
			parg.p_string = eq_message();
			error("%s", &parg);
			break;
			
		case A_VERSION:
			/*
			 * Print version number, without the "@(#)".
			 */
			cmd_exec();
			parg.p_string = version+4;
			error("%s", &parg);
			break;

		case A_QUIT:
			/*
			 * Exit.
			 */
			quit(0);

/*
 * Define abbreviation for a commonly used sequence below.
 */
#define	DO_SEARCH()	if (number <= 0) number = 1;	\
			mca_search();			\
			cmd_exec();			\
			multi_search((char *)NULL, number);


		case A_F_SEARCH:
			/*
			 * Search forward for a pattern.
			 * Get the first char of the pattern.
			 */
			search_type = SRCH_FORW;
			if (number <= 0)
				number = 1;
			mca_search();
			c = getcc();
			goto again;

		case A_B_SEARCH:
			/*
			 * Search backward for a pattern.
			 * Get the first char of the pattern.
			 */
			search_type = SRCH_BACK;
			if (number <= 0)
				number = 1;
			mca_search();
			c = getcc();
			goto again;

		case A_AGAIN_SEARCH:
			/*
			 * Repeat previous search.
			 */
			DO_SEARCH();
			break;
		
		case A_T_AGAIN_SEARCH:
			/*
			 * Repeat previous search, multiple files.
			 */
			search_type |= SRCH_PAST_EOF;
			DO_SEARCH();
			break;

		case A_REVERSE_SEARCH:
			/*
			 * Repeat previous search, in reverse direction.
			 */
			save_search_type = search_type;
			search_type = SRCH_REVERSE(search_type);
			DO_SEARCH();
			search_type = save_search_type;
			break;

		case A_T_REVERSE_SEARCH:
			/* 
			 * Repeat previous search, 
			 * multiple files in reverse direction.
			 */
			save_search_type = search_type;
			search_type = SRCH_REVERSE(search_type);
			search_type |= SRCH_PAST_EOF;
			DO_SEARCH();
			search_type = save_search_type;
			break;

		case A_HELP:
			/*
			 * Help.
			 */
			if (nohelp)
			{
				bell();
				break;
			}
			lower_left();
			clear_eol();
			putstr("help");
			cmd_exec();
			help();
			break;

		case A_EXAMINE:
			/*
			 * Edit a new file.  Get the filename.
			 */
			start_mca(A_EXAMINE, "Examine: ");
			c = getcc();
			goto again;
			
		case A_VISUAL:
			/*
			 * Invoke an editor on the input file.
			 */
#if EDITOR
			if (strcmp(get_filename(curr_ifile), "-") == 0)
			{
				error("Cannot edit standard input", NULL_PARG);
				break;
			}
			/*
			 * Expand the editor prototype string
			 * and pass it to the system to execute.
			 */
			cmd_exec();
			lsystem(pr_expand(editproto, 0));
			/*
			 * Re-edit the file, since data may have changed.
			 * Some editors even recreate the file, so flushing
			 * buffers is not sufficient.
			 */
			(void) edit(get_filename(curr_ifile), 0);
			break;
#else
			error("Command not available", NULL_PARG);
			break;
#endif

		case A_NEXT_FILE:
			/*
			 * Examine next file.
			 */
			if (number <= 0)
				number = 1;
			if (edit_next(number))
			{
				if (quit_at_eof && hit_eof)
					quit(0);
				parg.p_string = (number > 1) ? "(N-th) " : "";
				error("No %snext file", &parg);
			}
			break;

		case A_PREV_FILE:
			/*
			 * Examine previous file.
			 */
			if (number <= 0)
				number = 1;
			if (edit_prev(number))
			{
				parg.p_string = (number > 1) ? "(N-th) " : "";
				error("No %sprevious file", &parg);
			}
			break;

		case A_INDEX_FILE:
			/*
			 * Examine a particular file.
			 */
			if (number <= 0)
				number = 1;
			if (edit_index(number))
				error("No such file", NULL_PARG);
			break;

		case A_OPT_TOGGLE:
			start_mca(A_OPT_TOGGLE, "-");
			optflag = OPT_TOGGLE;
			c = getcc();
			goto again;

		case A_DISP_OPTION:
			/*
			 * Report a flag setting.
			 */
			start_mca(A_DISP_OPTION, "_");
			c = getcc();
			if (c == erase_char || c == kill_char)
				break;
			toggle_option(c, "", OPT_NO_TOGGLE);
			break;

		case A_FIRSTCMD:
			/*
			 * Set an initial command for new files.
			 */
			start_mca(A_FIRSTCMD, "+");
			c = getcc();
			goto again;

		case A_SHELL:
			/*
			 * Shell escape.
			 */
#if SHELL_ESCAPE
			start_mca(A_SHELL, "!");
			c = getcc();
			goto again;
#else
			error("Command not available", NULL_PARG);
			break;
#endif

		case A_SETMARK:
			/*
			 * Set a mark.
			 */
			start_mca(A_SETMARK, "mark: ");
			c = getcc();
			if (c == erase_char || c == kill_char ||
			    c == '\n' || c == '\r')
				break;
			setmark(c);
			break;

		case A_GOMARK:
			/*
			 * Go to a mark.
			 */
			start_mca(A_GOMARK, "goto mark: ");
			c = getcc();
			if (c == erase_char || c == kill_char || 
			    c == '\n' || c == '\r')
				break;
			gomark(c);
			break;

#if PIPEC
		case A_PIPE:
			start_mca(A_PIPE, "|mark: ");
			c = getcc();
			if (c == erase_char || c == kill_char)
				break;
			if (c == '\n' || c == '\r')
				c = '.';
			if (badmark(c))
				break;
			pipec = c;
			start_mca(A_PIPE, "!");
			c = getcc();
			goto again;
#endif

		case A_B_BRACKET:
		case A_F_BRACKET:
			start_mca(action, "Brackets: ");
			c = getcc();
			goto again;

		case A_PREFIX:
			/*
			 * The command is incomplete (more chars are needed).
			 * Display the current char, so the user knows
			 * what's going on, and get another character.
			 */
			if (mca != A_PREFIX)
			{
				start_mca(A_PREFIX, " ");
				cmd_reset();
				(void) cmd_char(c);
			}
			c = getcc();
			goto again;

		case A_NOACTION:
			break;

		default:
			bell();
			break;
		}
	}
}