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tscroll.c revision 1.11
      1 /*	$NetBSD: tscroll.c,v 1.11 2002/06/26 18:14:08 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)tscroll.c	8.4 (Berkeley) 7/27/94";
     41 #else
     42 __RCSID("$NetBSD: tscroll.c,v 1.11 2002/06/26 18:14:08 christos Exp $");
     43 #endif
     44 #endif				/* not lint */
     45 
     46 #include <string.h>
     47 #include <stdarg.h>
     48 #include "curses.h"
     49 #include "curses_private.h"
     50 
     51 #define	MAXRETURNSIZE	64
     52 
     53 char   *
     54 __tscroll(const char *cap, int n1, int n2)
     55 {
     56 	return (__parse_cap(cap, n1, n2));
     57 }
     58 
     59 /*
     60  * Routines to parse capabilities.  Derived from tgoto.c in termcap(3)
     61  * library.  Cap is a string containing printf type escapes to allow
     62  * scrolling.  The following escapes are defined for substituting n:
     63  *
     64  *	%d	as in printf
     65  *	%2	like %2d
     66  *	%3	like %3d
     67  *	%.	gives %c hacking special case characters
     68  *	%+x	like %c but adding x first
     69  *
     70  *	The codes below affect the state but don't use up a value.
     71  *
     72  *	%>xy	if value > x add y
     73  *	%i	increments n
     74  *	%%	gives %
     75  *	%B	BCD (2 decimal digits encoded in one byte)
     76  *	%D	Delta Data (backwards bcd)
     77  *
     78  * all other characters are ``self-inserting''.
     79  *
     80  * XXX:
     81  *	%r	reverse order of two parameters
     82  * is also defined but we don't support it (yet).
     83  */
     84 char	*
     85 __parse_cap (char const *cap, ...)
     86 {
     87 	va_list	ap;
     88 	static char result[MAXRETURNSIZE];
     89 	int     c, n;
     90 	char   *dp;
     91 	int	have_input;
     92 
     93 	va_start (ap, cap);
     94 	n = 0;			/* XXX gcc -Wuninitialized */
     95 
     96 	if (cap == NULL)
     97 		goto err;
     98 #ifdef DEBUG
     99 	{
    100 		int	i;
    101 
    102 		__CTRACE("__parse_cap: cap = ");
    103 		for (i = 0; i < strlen(cap); i++)
    104 			__CTRACE("%s", unctrl(cap[i]));
    105 		__CTRACE("\n");
    106 	}
    107 #endif
    108 	have_input = 0;
    109 	for (dp = result; (c = *cap++) != '\0';) {
    110 		if (c != '%') {
    111 			*dp++ = c;
    112 			continue;
    113 		}
    114 		switch (c = *cap++) {
    115 		case 'n':
    116 			if (!have_input) {
    117 				n = va_arg (ap, int);
    118 				have_input = 1;
    119 #ifdef DEBUG
    120 				__CTRACE ("__parse_cap: %%n, val = %d\n", n);
    121 #endif
    122 			}
    123 			n ^= 0140;
    124 			continue;
    125 		case 'd':
    126 			if (!have_input) {
    127 				n = va_arg (ap, int);
    128 				have_input = 1;
    129 #ifdef DEBUG
    130 				__CTRACE ("__parse_cap: %%d, val = %d\n", n);
    131 #endif
    132 			}
    133 			if (n < 10)
    134 				goto one;
    135 			if (n < 100)
    136 				goto two;
    137 			/* FALLTHROUGH */
    138 		case '3':
    139 			if (!have_input) {
    140 				n = va_arg (ap, int);
    141 				have_input = 1;
    142 #ifdef DEBUG
    143 				__CTRACE ("__parse_cap: %%3, val = %d\n", n);
    144 #endif
    145 			}
    146 			*dp++ = (n / 100) | '0';
    147 			n %= 100;
    148 			/* FALLTHROUGH */
    149 		case '2':
    150 			if (!have_input) {
    151 				n = va_arg (ap, int);
    152 				have_input = 1;
    153 #ifdef DEBUG
    154 				__CTRACE ("__parse_cap: %%2, val = %d\n", n);
    155 #endif
    156 			}
    157 	two:		*dp++ = n / 10 | '0';
    158 	one:		*dp++ = n % 10 | '0';
    159 			have_input = 0;
    160 			continue;
    161 		case '>':
    162 			if (!have_input) {
    163 				n = va_arg (ap, int);
    164 				have_input = 1;
    165 #ifdef DEBUG
    166 				__CTRACE ("__parse_cap: %%>, val = %d\n", n);
    167 #endif
    168 			}
    169 			if (n > *cap++)
    170 				n += *cap++;
    171 			else
    172 				cap++;
    173 			continue;
    174 		case '+':
    175 			if (!have_input) {
    176 				n = va_arg (ap, int);
    177 				have_input = 1;
    178 #ifdef DEBUG
    179 				__CTRACE ("__parse_cap: %%+, val = %d\n", n);
    180 #endif
    181 			}
    182 			n += *cap++;
    183 			/* FALLTHROUGH */
    184 		case '.':
    185 			if (!have_input) {
    186 				n = va_arg (ap, int);
    187 				have_input = 1;
    188 #ifdef DEBUG
    189 				__CTRACE ("__parse_cap: %%., val = %d\n", n);
    190 #endif
    191 			}
    192 			*dp++ = n;
    193 			have_input = 0;
    194 			continue;
    195 		case 'i':
    196 			if (!have_input) {
    197 				n = va_arg (ap, int);
    198 				have_input = 1;
    199 #ifdef DEBUG
    200 				__CTRACE ("__parse_cap: %%i, val = %d\n", n);
    201 #endif
    202 			}
    203 			n++;
    204 			continue;
    205 		case '%':
    206 			*dp++ = c;
    207 			continue;
    208 		case 'B':
    209 			if (!have_input) {
    210 				n = va_arg (ap, int);
    211 				have_input = 1;
    212 #ifdef DEBUG
    213 				__CTRACE ("__parse_cap: %%B, val = %d\n", n);
    214 #endif
    215 			}
    216 			n = (n / 10 << 4) + n % 10;
    217 			continue;
    218 		case 'D':
    219 			if (!have_input) {
    220 				n = va_arg (ap, int);
    221 				have_input = 1;
    222 #ifdef DEBUG
    223 				__CTRACE ("__parse_cap: %%D, val = %d\n", n);
    224 #endif
    225 			}
    226 			n = n - 2 * (n % 16);
    227 			continue;
    228 			/*
    229 			 * XXX
    230 			 * System V terminfo files have lots of extra gunk.
    231 			 * The only other one we've seen in capability strings
    232 			 * is %pN, and it seems to work okay if we ignore it.
    233 			 */
    234 		case 'p':
    235 			++cap;
    236 			continue;
    237 		default:
    238 			goto err;
    239 		}
    240 	}
    241 	*dp = '\0';
    242 	va_end (ap);
    243 	return (result);
    244 
    245 err:	va_end (ap);
    246 	return ((char *) "\0");
    247 }
    248