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tscroll.c revision 1.13
      1 /*	$NetBSD: tscroll.c,v 1.13 2007/01/21 13:25:36 jdc 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 
     34 #ifndef lint
     35 #if 0
     36 static char sccsid[] = "@(#)tscroll.c	8.4 (Berkeley) 7/27/94";
     37 #else
     38 __RCSID("$NetBSD: tscroll.c,v 1.13 2007/01/21 13:25:36 jdc Exp $");
     39 #endif
     40 #endif				/* not lint */
     41 
     42 #include <string.h>
     43 #include <stdarg.h>
     44 #include "curses.h"
     45 #include "curses_private.h"
     46 
     47 #define	MAXRETURNSIZE	64
     48 
     49 char   *
     50 __tscroll(const char *cap, int n1, int n2)
     51 {
     52 	return (__parse_cap(cap, n1, n2));
     53 }
     54 
     55 /*
     56  * Routines to parse capabilities.  Derived from tgoto.c in termcap(3)
     57  * library.  Cap is a string containing printf type escapes to allow
     58  * scrolling.  The following escapes are defined for substituting n:
     59  *
     60  *	%d	as in printf
     61  *	%2	like %2d
     62  *	%3	like %3d
     63  *	%.	gives %c hacking special case characters
     64  *	%+x	like %c but adding x first
     65  *
     66  *	The codes below affect the state but don't use up a value.
     67  *
     68  *	%>xy	if value > x add y
     69  *	%i	increments n
     70  *	%%	gives %
     71  *	%B	BCD (2 decimal digits encoded in one byte)
     72  *	%D	Delta Data (backwards bcd)
     73  *
     74  * all other characters are ``self-inserting''.
     75  *
     76  * XXX:
     77  *	%r	reverse order of two parameters
     78  * is also defined but we don't support it (yet).
     79  */
     80 char	*
     81 __parse_cap (char const *cap, ...)
     82 {
     83 	va_list	ap;
     84 	static char result[MAXRETURNSIZE];
     85 	int     c, n;
     86 	char   *dp;
     87 	int	have_input;
     88 
     89 	va_start (ap, cap);
     90 	n = 0;			/* XXX gcc -Wuninitialized */
     91 
     92 	if (cap == NULL)
     93 		goto err;
     94 #ifdef DEBUG
     95 	{
     96 		int	i;
     97 
     98 		__CTRACE(__CTRACE_MISC, "__parse_cap: cap = ");
     99 		for (i = 0; i < strlen(cap); i++)
    100 			__CTRACE(__CTRACE_MISC, "%s", unctrl(cap[i]));
    101 		__CTRACE(__CTRACE_MISC, "\n");
    102 	}
    103 #endif
    104 	have_input = 0;
    105 	for (dp = result; (c = *cap++) != '\0';) {
    106 		if (c != '%') {
    107 			*dp++ = c;
    108 			continue;
    109 		}
    110 		switch (c = *cap++) {
    111 		case 'n':
    112 			if (!have_input) {
    113 				n = va_arg (ap, int);
    114 				have_input = 1;
    115 #ifdef DEBUG
    116 				__CTRACE(__CTRACE_MISC,
    117 				    "__parse_cap: %%n, val = %d\n", n);
    118 #endif
    119 			}
    120 			n ^= 0140;
    121 			continue;
    122 		case 'd':
    123 			if (!have_input) {
    124 				n = va_arg (ap, int);
    125 				have_input = 1;
    126 #ifdef DEBUG
    127 				__CTRACE(__CTRACE_MISC,
    128 				    "__parse_cap: %%d, val = %d\n", n);
    129 #endif
    130 			}
    131 			if (n < 10)
    132 				goto one;
    133 			if (n < 100)
    134 				goto two;
    135 			/* FALLTHROUGH */
    136 		case '3':
    137 			if (!have_input) {
    138 				n = va_arg (ap, int);
    139 				have_input = 1;
    140 #ifdef DEBUG
    141 				__CTRACE(__CTRACE_MISC,
    142 				    "__parse_cap: %%3, val = %d\n", n);
    143 #endif
    144 			}
    145 			*dp++ = (n / 100) | '0';
    146 			n %= 100;
    147 			/* FALLTHROUGH */
    148 		case '2':
    149 			if (!have_input) {
    150 				n = va_arg (ap, int);
    151 				have_input = 1;
    152 #ifdef DEBUG
    153 				__CTRACE(__CTRACE_MISC,
    154 				    "__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(__CTRACE_MISC,
    167 				    "__parse_cap: %%>, val = %d\n", n);
    168 #endif
    169 			}
    170 			if (n > *cap++)
    171 				n += *cap++;
    172 			else
    173 				cap++;
    174 			continue;
    175 		case '+':
    176 			if (!have_input) {
    177 				n = va_arg (ap, int);
    178 				have_input = 1;
    179 #ifdef DEBUG
    180 				__CTRACE(__CTRACE_MISC,
    181 				    "__parse_cap: %%+, val = %d\n", n);
    182 #endif
    183 			}
    184 			n += *cap++;
    185 			/* FALLTHROUGH */
    186 		case '.':
    187 			if (!have_input) {
    188 				n = va_arg (ap, int);
    189 				have_input = 1;
    190 #ifdef DEBUG
    191 				__CTRACE(__CTRACE_MISC,
    192 				    "__parse_cap: %%., val = %d\n", n);
    193 #endif
    194 			}
    195 			*dp++ = n;
    196 			have_input = 0;
    197 			continue;
    198 		case 'i':
    199 			if (!have_input) {
    200 				n = va_arg (ap, int);
    201 				have_input = 1;
    202 #ifdef DEBUG
    203 				__CTRACE(__CTRACE_MISC,
    204 				    "__parse_cap: %%i, val = %d\n", n);
    205 #endif
    206 			}
    207 			n++;
    208 			continue;
    209 		case '%':
    210 			*dp++ = c;
    211 			continue;
    212 		case 'B':
    213 			if (!have_input) {
    214 				n = va_arg (ap, int);
    215 				have_input = 1;
    216 #ifdef DEBUG
    217 				__CTRACE(__CTRACE_MISC,
    218 				    "__parse_cap: %%B, val = %d\n", n);
    219 #endif
    220 			}
    221 			n = (n / 10 << 4) + n % 10;
    222 			continue;
    223 		case 'D':
    224 			if (!have_input) {
    225 				n = va_arg (ap, int);
    226 				have_input = 1;
    227 #ifdef DEBUG
    228 				__CTRACE(__CTRACE_MISC,
    229 				    "__parse_cap: %%D, val = %d\n", n);
    230 #endif
    231 			}
    232 			n = n - 2 * (n % 16);
    233 			continue;
    234 			/*
    235 			 * XXX
    236 			 * System V terminfo files have lots of extra gunk.
    237 			 * The only other one we've seen in capability strings
    238 			 * is %pN, and it seems to work okay if we ignore it.
    239 			 */
    240 		case 'p':
    241 			++cap;
    242 			continue;
    243 		default:
    244 			goto err;
    245 		}
    246 	}
    247 	*dp = '\0';
    248 	va_end (ap);
    249 	return (result);
    250 
    251 err:	va_end (ap);
    252 	return ((char *) "\0");
    253 }
    254