getline.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)getline.c	4.1	(ULTRIX)	7/17/90";
#endif lint

/************************************************************************
 *									*
 *	 	      Copyright (c) 1987, 1988 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

#include <cursesX.h>
#include <ctype.h>
#include <signal.h>

/* 
 * definitions for the key editing when in translate mode
 */

#define BSPACE	  010		/* ^h - backspace	*/
#define FSPACE	  014		/* ^l - forward space	*/

#define DELCHAR	 0177		/* DEL- delete previous */
#define DELINPUT  025		/* ^u - input kill*/

#define BWORD	  027		/* ^w - back word	*/
#define FWORD	  006		/* ^f - forward word	*/

#define INSERT    011		/* ^i - insert mode     */
#define REPLACE	  022		/* ^r - replace mode	*/

#define ENDINPUT   005		/* ^e - end line	*/
#define STARTINPUT 002		/* ^b - start of line	*/

#define NEXTLINE  016		/* ^n - next line	*/
#define PREVLINE  020		/* ^p - previous line	*/

#define KEYHELP	  013		/* ^k - show keys (help)*/

#define EXIT	  012		/* ^j - end of input	*/

#define EOT	  004		/* ^d - end of file     */
#define INTR	  003		/* ^c - interrupt       */

/*
 * getline()
 * 	Read a line from a window doing editing. The key definitions 
 *	above control the editing available. If quote is set non-zero
 *	then this represents a floating end character that CANNOT be
 *	deleted or altered.
 *
 *	NOTE: To make this function clearer macros are heavily used in
 *	      a way similar to PASCALs subfunctions. This is to save us
 *	      messing with lots of global variables!!
 */

/* 
 * following are several macros which are used in the getline function
 */


#define fchar(ptr) { 	/* skip forward one character */  \
		ptr++; \
		if (*ptr == '\n') { \
			cury++; \
			curx = 0; \
			ptr++; \
		} else \
			curx++; \
}

#define bchar(ptr) {	/* step backward one character */ \
		if (*--ptr == '\n')  { \
			ptr--; \
			cury--; \
			setcol(ptr); \
		} \
		curx--; \
}

			/* find start column of line */
#define startcol(line) (line == starty ? startx : 0)


#define setcol(ptr) { 	/* set curx to offset from last newline */ \
		curx = startcol(cury); \
		for (tp = ptr; tp >= line && *tp != '\n'; tp--) \
			curx++; \
}

getline(win, helpwin, line, len, quote)
WINDOW *win, *helpwin;
char *line;
int len;
int quote;
{	char *cp;		/* our current position			*/
	char *eol;		/* the end of the line			*/
	int   quotebias = 0;	/* used to stop overwriting quote	*/
	char *tp;
	int   mode = INSERT;
	int   redraw = FALSE;	/* true if we must redraw the screen	*/
	int   c;
	int   starty, startx, cury, curx, maxy;

	inputmode("INSERT");

	keypad(win, TRUE);
	getyx(win, starty, startx);	
	getyx(win, cury, curx);
	maxy = cury;

	cp = eol = line;
	if (quote) {
		quotebias = 1;
		*eol++ = quote;
		redraw = TRUE;
	}
	
	for(;;) {
		if (redraw)   {	/* redraw the screen */
			wmove(win , starty, startx);
			wclrtobot(win); 
			*eol = '\0';
			waddstr(win, line);
			wmove(win, cury, curx);
			redraw = FALSE;
		}
		wrefresh(win);
		c = wgetch(win);
		switch(c) {

		case EXIT:
			/*
			 * if previous char was back slash then this is an
			 * escaped newline so drop through to add it to the
			 * string. Otherwise return.
			 */
			if (cp == line || *(cp - 1) != '\\') {
				*eol = '\0';
				return;
			}
			/* drop through */

		default:
			/* 
			 * take care at end of string not to overwrite quote
			 */
			if (mode == INSERT || cp >= eol - quotebias) {
				/*
				 * check for buffer overflow
				 */
				if (eol - quotebias == line + len) {
					beep();
					break;
				}
				/* 
				 * move rest of line up to make space 
			  	 */
				for (tp = eol++; tp >= cp; tp--)
					tp[1] = tp[0];

				*cp++ = c;
				curx++;
				winsch(win, c);
				wmove(win, cury, curx);
			} else  {	/* replace mode */
				*cp++ = c;
				curx++;
				waddch(win, c);
			}
			/*
			 * if character was a newline redo the display since
			 * addch and insch functions hack the screen
			 */
			if (c == '\n') {
				maxy = ++cury;
				curx = 0;
				redraw = TRUE;
			}
			break;

		case REPLACE:
		case INSERT:
			mode = c;
			inputmode(mode == REPLACE ? "REPLACE" : "INSERT");
			break;

		case FSPACE:
		case KEY_RIGHT:
			if (cp == eol - quotebias)
				beep();
			else {
				fchar(cp);
				wmove(win, cury, curx);
			}
			break;

		case BSPACE:
		case KEY_LEFT:
			if (cp > line) {
				bchar(cp);
				wmove(win, cury, curx);
			} else
				beep();
			break;

		case DELCHAR:
			if (cp == line)
				beep();
			else {
				/* 
				 * save character in case a newline
				 */
				c = *(cp - 1);
				/* 
				 * move line down to remove character 
				 */
				cp--;
				eol--;
				for (tp = cp; tp < eol; tp++)
					tp[0] = tp[1];
				if (c == '\n') {
					cury--;
					maxy--;
					setcol(cp - 1);
					redraw = TRUE;
				} else {
					wmove(win, cury, --curx);
					wdelch(win);
				}
			}
			break;

		case DELINPUT:
			maxy = cury = starty;
			curx = startx;
			cp = eol = line;
			if (quote)
				*eol++ = quote;
			redraw = TRUE;
			break;

		case STARTINPUT:
			wmove(win, starty, startx);
			cury = starty;
			curx = startx;
			cp = line;
			break;

		case ENDINPUT:
			cury = maxy;
			cp = eol - quotebias;
			setcol(cp);
			wmove(win, maxy, --curx);
			break;

		case BWORD:
			/*
			 * skip to the start of the previous word
			 */
			if (cp > line)
				bchar(cp);

			while (cp > line && isspace(*cp))
				bchar(cp);

			while (cp > line && ! isspace(*cp))
				bchar(cp);
			
			if (cp > line && cp < eol)
				fchar(cp);

			wmove(win, cury, curx);
			break;

		case FWORD:
			/*
			 * skip to start of next word 
			 */
			while (cp < eol - quotebias && ! isspace(*cp)) 
				fchar(cp);

			while (cp < eol - quotebias && isspace(*cp))
				fchar(cp);

			wmove(win, cury, curx);
			break;

		case NEXTLINE:
		case KEY_DOWN:
			if (cury == maxy)
				beep();
			else { 
				curx = 0;
				wmove(win, ++cury, curx);
				while (*cp++ != '\n')
					;
			}
			break;

		case PREVLINE:
		case KEY_UP:
			if (cury == starty)
				beep();
			else {
				cury--;
				curx = startcol(cury);
				wmove(win, cury, curx);
				while (*--cp != '\n')
					;
			}
			break;

		case EOT:
			windup(0);
			break;

		case INTR:		/* simulate interrupt		*/
			windup(SIGINT);
			break;

		case KEYHELP:
		case KEY_F(15):		/* DEC standard mapping		*/
			werase(helpwin);
			wprintw(helpwin, 
"^h  back space    ^l  forward space   ^w  back word    ^f forward word\n");
			wprintw(helpwin, 
"^e  end of input  ^b  start of input  ^n  next line    ^p previous line\n");
			wprintw(helpwin, 
"DEL delete char   ^u  delete input    ^i  insert mode  ^r replace mode\n");
			wprintw(helpwin, 
"^d  exit          ^c  quit");
			wrefresh(helpwin);
			break;
		}

	}
}