lib/libcurses/tscroll.c

   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 }