release/src/router/libncurses/ncurses/tinfo/trim_sgr0.c

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  28
  29 /****************************************************************************
  30  *  Author: Thomas Dickey                                                   *
  31  ****************************************************************************/
  32
  33 #include <curses.priv.h>
  34
  35 #include <ctype.h>
  36
  37 #include <tic.h>
  38
  39 MODULE_ID("$Id: trim_sgr0.c,v 1.15 2012/12/15 20:57:17 tom Exp $")
  40
  41 #undef CUR
  42 #define CUR tp->
  43
  44 #define CSI       233
  45 #define ESC       033           /* ^[ */
  46 #define L_BRACK   '['
  47
  48 static char *
  49 set_attribute_9(TERMTYPE *tp, int flag)
  50 {
  51     const char *value;
  52     char *result;
  53
  54     value = tparm(set_attributes, 0, 0, 0, 0, 0, 0, 0, 0, flag);
  55     if (PRESENT(value))
  56         result = strdup(value);
  57     else
  58         result = 0;
  59     return result;
  60 }
  61
  62 static int
  63 is_csi(const char *s)
  64 {
  65     int result = 0;
  66     if (s != 0) {
  67         if (UChar(s[0]) == CSI)
  68             result = 1;
  69         else if (s[0] == ESC && s[1] == L_BRACK)
  70             result = 2;
  71     }
  72     return result;
  73 }
  74
  75 static char *
  76 skip_zero(char *s)
  77 {
  78     if (s[0] == '0') {
  79         if (s[1] == ';')
  80             s += 2;
  81         else if (isalpha(UChar(s[1])))
  82             s += 1;
  83     }
  84     return s;
  85 }
  86
  87 static const char *
  88 skip_delay(const char *s)
  89 {
  90     if (s[0] == '$' && s[1] == '<') {
  91         s += 2;
  92         while (isdigit(UChar(*s)) || *s == '/')
  93             ++s;
  94         if (*s == '>')
  95             ++s;
  96     }
  97     return s;
  98 }
  99
 100 /*
 101  * Improve similar_sgr a little by moving the attr-string from the beginning
 102  * to the end of the s-string.
 103  */
 104 static bool
 105 rewrite_sgr(char *s, char *attr)
 106 {
 107     if (s != 0) {
 108         if (PRESENT(attr)) {
 109             size_t len_s = strlen(s);
 110             size_t len_a = strlen(attr);
 111
 112             if (len_s > len_a && !strncmp(attr, s, len_a)) {
 113                 unsigned n;
 114                 TR(TRACE_DATABASE, ("rewrite:\n\t%s", s));
 115                 for (n = 0; n < len_s - len_a; ++n) {
 116                     s[n] = s[n + len_a];
 117                 }
 118                 _nc_STRCPY(s + n, attr, strlen(s) + 1);
 119                 TR(TRACE_DATABASE, ("to:\n\t%s", s));
 120             }
 121         }
 122         return TRUE;
 123     }
 124     return FALSE;               /* oops */
 125 }
 126
 127 static bool
 128 similar_sgr(char *a, char *b)
 129 {
 130     bool result = FALSE;
 131     if (a != 0 && b != 0) {
 132         int csi_a = is_csi(a);
 133         int csi_b = is_csi(b);
 134         size_t len_a;
 135         size_t len_b;
 136
 137         TR(TRACE_DATABASE, ("similar_sgr:\n\t%s\n\t%s",
 138                             _nc_visbuf2(1, a),
 139                             _nc_visbuf2(2, b)));
 140         if (csi_a != 0 && csi_b != 0 && csi_a == csi_b) {
 141             a += csi_a;
 142             b += csi_b;
 143             if (*a != *b) {
 144                 a = skip_zero(a);
 145                 b = skip_zero(b);
 146             }
 147         }
 148         len_a = strlen(a);
 149         len_b = strlen(b);
 150         if (len_a && len_b) {
 151             if (len_a > len_b)
 152                 result = (strncmp(a, b, len_b) == 0);
 153             else
 154                 result = (strncmp(a, b, len_a) == 0);
 155         }
 156         TR(TRACE_DATABASE, ("...similar_sgr: %d\n\t%s\n\t%s", result,
 157                             _nc_visbuf2(1, a),
 158                             _nc_visbuf2(2, b)));
 159     }
 160     return result;
 161 }
 162
 163 static unsigned
 164 chop_out(char *string, unsigned i, unsigned j)
 165 {
 166     TR(TRACE_DATABASE, ("chop_out %d..%d from %s", i, j, _nc_visbuf(string)));
 167     while (string[j] != '\0') {
 168         string[i++] = string[j++];
 169     }
 170     string[i] = '\0';
 171     return i;
 172 }
 173
 174 /*
 175  * Compare, ignoring delays.  Some of the delay values are inconsistent, and
 176  * we do not want to be stopped by that.
 177  *
 178  * Returns the number of chars from 'full' that we matched.  If any mismatch
 179  * occurs, return zero.
 180  */
 181 static unsigned
 182 compare_part(const char *part, const char *full)
 183 {
 184     const char *next_part;
 185     const char *next_full;
 186     unsigned used_full = 0;
 187     unsigned used_delay = 0;
 188
 189     while (*part != 0) {
 190         if (*part != *full) {
 191             used_full = 0;
 192             break;
 193         }
 194
 195         /*
 196          * Adjust the return-value to allow the rare case of
 197          *      string<delay>string
 198          * to remove the whole piece.  The most common case is a delay at the
 199          * end of the string.  The adjusted string will retain the delay, which
 200          * is conservative.
 201          */
 202         if (used_delay != 0) {
 203             used_full += used_delay;
 204             used_delay = 0;
 205         }
 206         if (*part == '$' && *full == '$') {
 207             next_part = skip_delay(part);
 208             next_full = skip_delay(full);
 209             if (next_part != part && next_full != full) {
 210                 used_delay += (unsigned) (next_full - full);
 211                 full = next_full;
 212                 part = next_part;
 213                 continue;
 214             }
 215         }
 216         ++used_full;
 217         ++part;
 218         ++full;
 219     }
 220     return used_full;
 221 }
 222
 223 /*
 224  * While 'sgr0' is the "same" as termcap 'me', there is a compatibility issue.
 225  * The sgr/sgr0 capabilities include setting/clearing alternate character set
 226  * mode.  A termcap application cannot use sgr, so sgr0 strings that reset
 227  * alternate character set mode will be misinterpreted.  Here, we remove those
 228  * from the more common ISO/ANSI/VT100 entries, which have sgr0 agreeing with
 229  * sgr.
 230  *
 231  * This function returns the modified sgr0 if it can be modified, a null if
 232  * an error occurs, or the original sgr0 if no change is needed.
 233  */
 234 NCURSES_EXPORT(char *)
 235 _nc_trim_sgr0(TERMTYPE *tp)
 236 {
 237     char *result = exit_attribute_mode;
 238
 239     T((T_CALLED("_nc_trim_sgr0()")));
 240
 241     if (PRESENT(exit_attribute_mode)
 242         && PRESENT(set_attributes)) {
 243         bool found = FALSE;
 244         char *on = set_attribute_9(tp, 1);
 245         char *off = set_attribute_9(tp, 0);
 246         char *end = strdup(exit_attribute_mode);
 247         char *tmp;
 248         size_t i, j, k;
 249
 250         TR(TRACE_DATABASE, ("checking if we can trim sgr0 based on sgr"));
 251         TR(TRACE_DATABASE, ("sgr0       %s", _nc_visbuf(end)));
 252         TR(TRACE_DATABASE, ("sgr(9:off) %s", _nc_visbuf(off)));
 253         TR(TRACE_DATABASE, ("sgr(9:on)  %s", _nc_visbuf(on)));
 254
 255         if (!rewrite_sgr(on, enter_alt_charset_mode)
 256             || !rewrite_sgr(off, exit_alt_charset_mode)
 257             || !rewrite_sgr(end, exit_alt_charset_mode)) {
 258             FreeIfNeeded(off);
 259         } else if (similar_sgr(off, end)
 260                    && !similar_sgr(off, on)) {
 261             TR(TRACE_DATABASE, ("adjusting sgr(9:off) : %s", _nc_visbuf(off)));
 262             result = off;
 263             /*
 264              * If rmacs is a substring of sgr(0), remove that chunk.
 265              */
 266             if (exit_alt_charset_mode != 0) {
 267                 TR(TRACE_DATABASE, ("scan for rmacs %s", _nc_visbuf(exit_alt_charset_mode)));
 268                 j = strlen(off);
 269                 k = strlen(exit_alt_charset_mode);
 270                 if (j > k) {
 271                     for (i = 0; i <= (j - k); ++i) {
 272                         unsigned k2 = compare_part(exit_alt_charset_mode,
 273                                                    off + i);
 274                         if (k2 != 0) {
 275                             found = TRUE;
 276                             chop_out(off, (unsigned) i, (unsigned) (i + k2));
 277                             break;
 278                         }
 279                     }
 280                 }
 281             }
 282             /*
 283              * SGR 10 would reset to normal font.
 284              */
 285             if (!found) {
 286                 if ((i = (size_t) is_csi(off)) != 0
 287                     && off[strlen(off) - 1] == 'm') {
 288                     TR(TRACE_DATABASE, ("looking for SGR 10 in %s",
 289                                         _nc_visbuf(off)));
 290                     tmp = skip_zero(off + i);
 291                     if (tmp[0] == '1'
 292                         && skip_zero(tmp + 1) != tmp + 1) {
 293                         i = (size_t) (tmp - off);
 294                         if (off[i - 1] == ';')
 295                             i--;
 296                         j = (size_t) (skip_zero(tmp + 1) - off);
 297                         (void) chop_out(off, (unsigned) i, (unsigned) j);
 298                         found = TRUE;
 299                     }
 300                 }
 301             }
 302             if (!found
 303                 && (tmp = strstr(end, off)) != 0
 304                 && strcmp(end, off) != 0) {
 305                 i = (size_t) (tmp - end);
 306                 j = strlen(off);
 307                 tmp = strdup(end);
 308                 chop_out(tmp, (unsigned) i, (unsigned) j);
 309                 free(off);
 310                 result = tmp;
 311             }
 312             TR(TRACE_DATABASE, ("...adjusted sgr0 : %s", _nc_visbuf(result)));
 313             if (!strcmp(result, exit_attribute_mode)) {
 314                 TR(TRACE_DATABASE, ("...same result, discard"));
 315                 free(result);
 316                 result = exit_attribute_mode;
 317             }
 318         } else {
 319             /*
 320              * Either the sgr does not reference alternate character set,
 321              * or it is incorrect.  That's too hard to decide right now.
 322              */
 323             free(off);
 324         }
 325         FreeIfNeeded(end);
 326         FreeIfNeeded(on);
 327     } else {
 328         /*
 329          * Possibly some applications are confused if sgr0 contains rmacs,
 330          * but that would be a different bug report -TD
 331          */
 332     }
 333
 334     returnPtr(result);
 335 }