command.c

早期freebsd实现

/*
 * User-level command processor.
 */

#include "less.h"
#include "position.h"
#include "option.h"
#include "cmd.h"

#define	NO_MCA		0
#define	MCA_DONE	1
#define	MCA_MORE	2

extern int erase_char, kill_char;
extern int ispipe;
extern int sigs;
extern int quit_at_eof;
extern int hit_eof;
extern int sc_width;
extern int sc_height;
extern int swindow;
extern int jump_sline;
extern int quitting;
extern int scroll;
extern int nohelp;
extern int ignore_eoi;
extern char *every_first_cmd;
extern char version[];
extern struct scrpos initial_scrpos;
extern IFILE curr_ifile;
#if EDITOR
extern char *editor;
extern char *editproto;
#endif
extern int screen_trashed;	/* The screen has been overwritten */

static char ungot[100];
static char *ungotp = NULL;
#if SHELL_ESCAPE
static char *shellcmd = NULL;	/* For holding last shell command for "!!" */
#endif
static int mca;			/* The multicharacter command (action) */
static int search_type;		/* The previous type of search */
static int number;		/* The number typed by the user */
static char optchar;
static int optflag;
#if PIPEC
static char pipec;
#endif

static void multi_search();

/*
 * Move the cursor to lower left before executing a command.
 * This looks nicer if the command takes a long time before
 * updating the screen.
 */
	static void
cmd_exec()
{
	lower_left();
	flush();
}

/*
 * Set up the display to start a new multi-character command.
 */
	static void
start_mca(action, prompt)
	int action;
	char *prompt;
{
	mca = action;
	lower_left();
	clear_eol();
	cmd_putstr(prompt);
}

/*
 * Set up the display to start a new search command.
 */
	static void
mca_search()
{
	switch (SRCH_DIR(search_type))
	{
	case SRCH_FORW:
		mca = A_F_SEARCH;
		break;
	case SRCH_BACK:
		mca = A_B_SEARCH;
		break;
	}

	lower_left();
	clear_eol();

	if (search_type & SRCH_FIRST_FILE)
		cmd_putstr("@");

	if (search_type & SRCH_PAST_EOF)
		cmd_putstr("*");

	if (search_type & SRCH_NOMATCH)
		cmd_putstr("!");

	switch (SRCH_DIR(search_type))
	{
	case SRCH_FORW:
		cmd_putstr("/");
		break;
	case SRCH_BACK:
		cmd_putstr("?");
		break;
	}
}

/*
 * Execute a multicharacter command.
 */
	static void
exec_mca()
{
	register char *cbuf;
	register char *s;

	cmd_exec();
	cbuf = get_cmdbuf();

	switch (mca)
	{
	case A_F_SEARCH:
	case A_B_SEARCH:
		multi_search(cbuf, number);
		break;
	case A_FIRSTCMD:
		/*
		 * Skip leading spaces or + signs in the string.
		 */
		while (*cbuf == '+' || *cbuf == ' ')
			cbuf++;
		if (every_first_cmd != NULL)
			free(every_first_cmd);
		if (*cbuf == '\0')
			every_first_cmd = NULL;
		else
			every_first_cmd = save(cbuf);
		break;
	case A_OPT_TOGGLE:
		toggle_option(optchar, cbuf, optflag);
		optchar = '\0';
		break;
	case A_F_BRACKET:
		match_brac(cbuf[0], cbuf[1], 1, number);
		break;
	case A_B_BRACKET:
		match_brac(cbuf[1], cbuf[0], 0, number);
		break;
	case A_EXAMINE:
		/*
		 * Ignore leading spaces and glob the filename.
		 */
		cbuf = skipsp(cbuf);
		s = glob(cbuf);
		if (s != NULL)
		{
			edit_list(s);
			free(s);
		} else
			edit_list(cbuf);
		break;
#if SHELL_ESCAPE
	case A_SHELL:
		/*
		 * !! just uses whatever is in shellcmd.
		 * Otherwise, copy cmdbuf to shellcmd,
		 * expanding any special characters ("%" or "#").
		 */
		if (*cbuf != '!')
		{
			if (shellcmd != NULL)
				free(shellcmd);
			shellcmd = fexpand(cbuf);
			if (shellcmd == NULL)
				break;
		}

		if (shellcmd == NULL)
			lsystem("");
		else
			lsystem(shellcmd);
		error("!done", NULL_PARG);
		break;
#endif
#if PIPEC
	case A_PIPE:
		(void) pipe_mark(pipec, cbuf);
		error("|done", NULL_PARG);
		break;
#endif
	}
}

/*
 * Add a character to a multi-character command.
 */
	static int
mca_char(c)
	int c;
{
	char *p;
	int flag;
	char buf[3];

	switch (mca)
	{
	case 0:
		/*
		 * Not in a multicharacter command.
		 */
		return (NO_MCA);

	case A_PREFIX:
		/*
		 * In the prefix of a command.
		 * This not considered a multichar command
		 * (even tho it uses cmdbuf, etc.).
		 * It is handled in the commands() switch.
		 */
		return (NO_MCA);

	case A_DIGIT:
		/*
		 * Entering digits of a number.
		 * Terminated by a non-digit.
		 */
		if ((c < '0' || c > '9') &&
			c != erase_char && c != kill_char)
		{
			/*
			 * Not part of the number.
			 * Treat as a normal command character.
			 */
			number = cmd_int();
			mca = 0;
			return (NO_MCA);
		}
		break;

	case A_OPT_TOGGLE:
		/*
		 * Special case for the TOGGLE_OPTION command.
		 * If the option letter which was entered is a
		 * single-char option, execute the command immediately,
		 * so user doesn't have to hit RETURN.
		 * If the first char is + or -, this indicates
		 * OPT_UNSET or OPT_SET respectively, instead of OPT_TOGGLE.
		 */
		if (c == erase_char || c == kill_char)
			break;
		if (optchar != '\0' && optchar != '+' && optchar != '-')
			/*
			 * We already have the option letter.
			 */
			break;
		switch (c)
		{
		case '+':
			optflag = OPT_UNSET;
			break;
		case '-':
			optflag = OPT_SET;
			break;
		default:
			optchar = c;
			if (optflag != OPT_TOGGLE || single_char_option(c))
			{
				toggle_option(c, "", optflag);
				return (MCA_DONE);
			}
			break;
		}
		if (optchar == '+' || optchar == '-')
		{
			optchar = c;
			break;
		}
		/*
		 * Display a prompt appropriate for the option letter.
		 */
		if ((p = opt_prompt(c)) == NULL)
		{
			buf[0] = '-';
			buf[1] = c;
			buf[2] = '\0';
			p = buf;
		}
		start_mca(A_OPT_TOGGLE, p);
		return (MCA_MORE);

	case A_F_SEARCH:
	case A_B_SEARCH:
		/*
		 * Special case for search commands.
		 * Certain characters as the first char of 
		 * the pattern have special meaning:
		 *	!  Toggle the NOMATCH flag
		 *	*  Toggle the PAST_EOF flag
		 *	@  Toggle the FIRST_FILE flag
		 */
		if (len_cmdbuf() > 0)
			/*
			 * Only works for the first char of the pattern.
			 */
			break;

		flag = 0;
		switch (c)
		{
		case '!':
			flag = SRCH_NOMATCH;
			break;
		case '@':
			flag = SRCH_FIRST_FILE;
			break;
		case '*':
			flag = SRCH_PAST_EOF;
			break;
		}
		if (flag != 0)
		{
			search_type ^= flag;
			mca_search();
			return (MCA_MORE);
		}
		break;
	}

	/*
	 * Any other multicharacter command
	 * is terminated by a newline.
	 */
	if (c == '\n' || c == '\r')
	{
		/*
		 * Execute the command.
		 */
		exec_mca();
		return (MCA_DONE);
	}
	/*
	 * Append the char to the command buffer.
	 */
	if (cmd_char(c))
		/*
		 * Abort the multi-char command.
		 */
		return (MCA_DONE);

	if ((mca == A_F_BRACKET || mca == A_B_BRACKET) && len_cmdbuf() >= 2)
	{
		/*
		 * Special case for the bracket-matching commands.
		 * Execute the command after getting exactly two
		 * characters from the user.
		 */
		exec_mca();
		return (MCA_DONE);
	}

	/*
	 * Need another character.
	 */
	return (MCA_MORE);
}

/*
 * Display the appropriate prompt.
 */
	static void
prompt()
{
	register char *p;

	if (ungotp != NULL && ungotp > ungot)
	{
		/*
		 * No prompt necessary if commands are from 
		 * ungotten chars rather than from the user.
		 */
		return;
	}

	/*
	 * If nothing is displayed yet, display starting from initial_scrpos.
	 */
	if (empty_screen())
	{
		if (initial_scrpos.pos == NULL_POSITION)
			/*
			 * {{ Maybe this should be:
			 *    jump_loc(ch_zero(), jump_sline);
			 *    but this behavior seems rather unexpected 
			 *    on the first screen. }}
			 */
			jump_loc(ch_zero(), 1);
		else
			jump_loc(initial_scrpos.pos, initial_scrpos.ln);
	} else if (screen_trashed)
		repaint();

	/*
	 * If the -E flag is set and we've hit EOF on the last file, quit.
	 */
	if (quit_at_eof == 2 && hit_eof && 
	    next_ifile(curr_ifile) == NULL_IFILE)
		quit(0);

	/*
	 * Select the proper prompt and display it.
	 */
	lower_left();
	clear_eol();
	p = pr_string();
	if (p == NULL)
		putchr(':');
	else
	{
		so_enter();
		putstr(p);
		so_exit();
	}
#if __MSDOS__
	scroll_bar();
#endif
}

/*
 * Get command character.
 * The character normally comes from the keyboard,
 * but may come from ungotten characters
 * (characters previously given to ungetcc or ungetsc).
 */
	static int
getcc()
{
	if (ungotp == NULL)
		/*
		 * Normal case: no ungotten chars, so get one from the user.
		 */
		return (getchr());

	if (ungotp > ungot)
		/*
		 * Return the next ungotten char.
		 */
		return (*--ungotp);

	/*
	 * We have just run out of ungotten chars.
	 */
	ungotp = NULL;
	if (len_cmdbuf() == 0 || !empty_screen())
		return (getchr());
	/*
	 * Command is incomplete, so try to complete it.
	 */
	switch (mca)
	{
	case A_DIGIT:
		/*
		 * We have a number but no command.  Treat as #g.
		 */
		return ('g');

	case A_F_SEARCH:
	case A_B_SEARCH:
		/*
		 * We have "/string" but no newline.  Add the \n.
		 */
		return ('\n'); 

	default:
		/*
		 * Some other incomplete command.  Let user complete it.
		 */
		return (getchr());
	}
}

/*
 * "Unget" a command character.
 * The next getcc() will return this character.
 */
	public void
ungetcc(c)
	int c;
{
	if (ungotp == NULL)
		ungotp = ungot;
	if (ungotp >= ungot + sizeof(ungot))
	{
		error("ungetcc overflow", NULL_PARG);
		quit(1);
	}
	*ungotp++ = c;
}

/*
 * Unget a whole string of command characters.
 * The next sequence of getcc()'s will return this string.
 */
	public void
ungetsc(s)
	char *s;
{
	register char *p;

	for (p = s + strlen(s) - 1;  p >= s;  p--)
		ungetcc(*p);
}

/*
 * Search for a pattern, possibly in multiple files.
 * If SRCH_FIRST_FILE is set, begin searching at the first file.
 * If SRCH_PAST_EOF is set, continue the search thru multiple files.
 */
	static void
multi_search(pattern, n)
	char *pattern;
	int n;
{
	register int nomore;
	char *curr_filename;
	int changed_file;

	changed_file = 0;
	curr_filename = get_filename(curr_ifile);

	if (search_type & SRCH_FIRST_FILE)
	{
		/*
		 * Start at the first (or last) file 
		 * in the command line list.
		 */
		if (SRCH_DIR(search_type) == SRCH_FORW)
			nomore = edit_first();
		else
			nomore = edit_last();
		if (nomore)
			return;
		changed_file = 1;
		search_type &= ~SRCH_FIRST_FILE;
	}

	for (;;)
	{
		if ((n = search(search_type, pattern, n)) == 0)
			/*
			 * Found it.
			 */
			return;

		if (n < 0)
			/*
			 * Some kind of error in the search.
			 * Error message has been printed by search().
			 */
			break;

		if ((search_type & SRCH_PAST_EOF) == 0)
			/*
			 * We didn't find a match, but we're
			 * supposed to search only one file.
			 */
			break;
		/*
		 * Move on to the next file.
		 */
		if (SRCH_DIR(search_type) == SRCH_BACK)
			nomore = edit_prev(1);
		else
			nomore = edit_next(1);
		if (nomore)
			break;
		changed_file = 1;
	}

	/*
	 * Didn't find it.
	 * Print an error message if we haven't already.
	 */
	if (n > 0)
		error("Pattern not found", NULL_PARG);

	if (changed_file)
		/*