1 /**************************************************************************** 2 * Copyright (c) 2005-2010,2012 Free Software Foundation, Inc. * 3 * * 4 * Permission is hereby granted, free of charge, to any person obtaining a * 5 * copy of this software and associated documentation files (the * 6 * "Software"), to deal in the Software without restriction, including * 7 * without limitation the rights to use, copy, modify, merge, publish, * 8 * distribute, distribute with modifications, sublicense, and/or sell * 9 * copies of the Software, and to permit persons to whom the Software is * 10 * furnished to do so, subject to the following conditions: * 11 * * 12 * The above copyright notice and this permission notice shall be included * 13 * in all copies or substantial portions of the Software. * 14 * * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * 16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * 17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * 18 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * 19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * 20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * 21 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * 22 * * 23 * Except as contained in this notice, the name(s) of the above copyright * 24 * holders shall not be used in advertising or otherwise to promote the * 25 * sale, use or other dealings in this Software without prior written * 26 * authorization. * 27 ****************************************************************************/ 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 } 336