NetBSD/lib/libterm/tgoto.c

/*	$NetBSD: tgoto.c,v 1.15 1999/09/16 11:45:49 lukem Exp $	*/

/*
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)tgoto.c	8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: tgoto.c,v 1.15 1999/09/16 11:45:49 lukem Exp $");
#endif
#endif /* not lint */

#include <errno.h>
#include <string.h>
#include <termcap.h>

#define	CTRL(c)	((c) & 037)

#define MAXRETURNSIZE 64

char	*UP;
char	*BC;

/*
 * Routine to perform cursor addressing.
 * CM is a string containing printf type escapes to allow
 * cursor addressing.  We start out ready to print the destination
 * line, and switch each time we print row or column.
 * The following escapes are defined for substituting row/column:
 *
 *	%d	as in printf
 *	%2	like %2d
 *	%3	like %3d
 *	%.	gives %c hacking special case characters
 *	%+x	like %c but adding x first
 *
 *	The codes below affect the state but don't use up a value.
 *
 *	%>xy	if value > x add y
 *	%r	reverses row/column
 *	%i	increments row/column (for one origin indexing)
 *	%%	gives %
 *	%B	BCD (2 decimal digits encoded in one byte)
 *	%D	Delta Data (backwards bcd)
 *
 * all other characters are ``self-inserting''.
 */
char *
tgoto(CM, destcol, destline)
	const char *CM;
	int destcol, destline;
{
	static char result[MAXRETURNSIZE];

        if (t_goto(NULL, CM, destcol, destline, result, MAXRETURNSIZE) >= 0)
                return result;
        else
                return ("OOPS");
}

/*
 * New interface.  Functionally the same as tgoto but uses the tinfo struct
 * to set UP and BC.  The arg buffer is filled with the result string, limit
 * defines the maximum number of chars allowed in buffer.  The function
 * returns 0 on success, -1 otherwise.
 */
int
t_goto(info, CM, destcol, destline, buffer, limit)
	struct tinfo *info;
        const char *CM;
        int destcol;
        int destline;
        char *buffer;
        size_t limit;
{
	static char added[10];
	const char *cp = CM;
	char *dp = buffer;
        char *old_up = UP, *old_bc = BC;
        char new_up[MAXRETURNSIZE], new_bc[MAXRETURNSIZE], *up_ptr, *bc_ptr;
	int c;
	size_t count = MAXRETURNSIZE;
	int oncol = 0;
	int which = destline;

	/* CM is checked below */

        if (info != NULL)
        {
                up_ptr = new_up;
                bc_ptr = new_bc;
                UP = t_getstr(info, "up", &up_ptr, &count);
                count = MAXRETURNSIZE;
                BC = t_getstr(info, "bc", &bc_ptr, &count);
        }
        
	if (cp == 0) {
                errno = EINVAL;
toohard:
                UP = old_up;
                BC = old_bc;
		return -1;
	}
	added[0] = '\0';
	while ((c = *cp++) != '\0') {
		if (c != '%') {
copy:
			*dp++ = c;
			if (dp >= &buffer[limit])
                        {
                                errno = E2BIG;
                                goto toohard;
                        }
			continue;
		}
		switch (c = *cp++) {

#ifdef CM_N
		case 'n':
			destcol ^= 0140;
			destline ^= 0140;
			goto setwhich;
#endif

		case 'd':
			if (which < 10)
				goto one;
			if (which < 100)
				goto two;
			/* FALLTHROUGH */

		case '3':
			if (which >= 1000) {
                                errno = E2BIG;
                                goto toohard;
                        }
  			*dp++ = (which / 100) | '0';
			if (dp >= &buffer[limit]) {
                                errno = E2BIG;
                                goto toohard;
                        }
			which %= 100;
			/* FALLTHROUGH */

		case '2':
two:
			*dp++ = which / 10 | '0';
			if (dp >= &buffer[limit]) {
                                errno = E2BIG;
                                goto toohard;
                        }
one:
			*dp++ = which % 10 | '0';
			if (dp >= &buffer[limit]) {
                                errno = E2BIG;
                                goto toohard;
                        }
                        
swap:
			oncol = 1 - oncol;
setwhich:
			which = oncol ? destcol : destline;
			continue;

#ifdef CM_GT
		case '>':
			if (which > *cp++)
				which += *cp++;
			else
				cp++;
			continue;
#endif

		case '+':
			which += *cp++;
			/* FALLTHROUGH */

		case '.':
			/*
			 * This code is worth scratching your head at for a
			 * while.  The idea is that various weird things can
			 * happen to nulls, EOT's, tabs, and newlines by the
			 * tty driver, arpanet, and so on, so we don't send
			 * them if we can help it.
			 *
			 * Tab is taken out to get Ann Arbors to work, otherwise
			 * when they go to column 9 we increment which is wrong
			 * because bcd isn't continuous.  We should take out
			 * the rest too, or run the thing through more than
			 * once until it doesn't make any of these, but that
			 * would make termlib (and hence pdp-11 ex) bigger,
			 * and also somewhat slower.  This requires all
			 * programs which use termlib to stty tabs so they
			 * don't get expanded.  They should do this anyway
			 * because some terminals use ^I for other things,
			 * like nondestructive space.
			 */
			if (which == 0 || which == CTRL('d') || /* which == '\t' || */ which == '\n') {
				if (oncol || UP) { /* Assumption: backspace works */
					char *add = oncol ? (BC ? BC : "\b") : UP;

					/*
					 * Loop needed because newline happens
					 * to be the successor of tab.
					 */
					do {
						if (strlen(added) + strlen(add) >= sizeof(added))
                                                {
                                                        errno = E2BIG;
                                                        goto toohard;
                                                }
                                                
                                                (void)strcat(added, add);
						which++;
					} while (which == '\n');
				}
			}
			*dp++ = which;
			if (dp >= &buffer[limit])
                        {
                                errno = E2BIG;
                                goto toohard;
                        }
			goto swap;

		case 'r':
			oncol = 1;
			goto setwhich;

		case 'i':
			destcol++;
			destline++;
			which++;
			continue;

		case '%':
			goto copy;

#ifdef CM_B
		case 'B':
			which = (which/10 << 4) + which%10;
			continue;
#endif

#ifdef CM_D
		case 'D':
			which = which - 2 * (which%16);
			continue;
#endif

		default:
                        errno = EINVAL;
                        goto toohard;
		}
	}
	if (dp + strlen(added) >= &buffer[limit])
        {
                errno = E2BIG;
                goto toohard;
        }
        
        (void)strcpy(dp, added);
        UP = old_up;
        BC = old_bc;
	return 0;
}