1 /* 2 * Copyright (C) 1984-2015 Mark Nudelman 3 * 4 * You may distribute under the terms of either the GNU General Public 5 * License or the Less License, as specified in the README file. 6 * 7 * For more information, see the README file. 8 */ 9 10 11 /* 12 * Prompting and other messages. 13 * There are three flavors of prompts, SHORT, MEDIUM and LONG, 14 * selected by the -m/-M options. 15 * There is also the "equals message", printed by the = command. 16 * A prompt is a message composed of various pieces, such as the 17 * name of the file being viewed, the percentage into the file, etc. 18 */ 19 20 #include "less.h" 21 #include "position.h" 22 23 extern int pr_type; 24 extern int new_file; 25 extern int sc_width; 26 extern int so_s_width, so_e_width; 27 extern int linenums; 28 extern int hshift; 29 extern int sc_height; 30 extern int jump_sline; 31 extern int less_is_more; 32 extern IFILE curr_ifile; 33 #if EDITOR 34 extern char *editor; 35 extern char *editproto; 36 #endif 37 38 /* 39 * Prototypes for the three flavors of prompts. 40 * These strings are expanded by pr_expand(). 41 */ 42 static constant char s_proto[] = 43 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t"; 44 static constant char m_proto[] = 45 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t"; 46 static constant char M_proto[] = 47 "?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t"; 48 static constant char e_proto[] = 49 "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t"; 50 static constant char h_proto[] = 51 "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done"; 52 static constant char w_proto[] = 53 "Waiting for data"; 54 static constant char more_proto[] = 55 "--More--(?eEND ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t)"; 56 57 public char *prproto[3]; 58 public char constant *eqproto = e_proto; 59 public char constant *hproto = h_proto; 60 public char constant *wproto = w_proto; 61 62 static char message[PROMPT_SIZE]; 63 static char *mp; 64 65 /* 66 * Initialize the prompt prototype strings. 67 */ 68 public void 69 init_prompt(void) 70 { 71 prproto[0] = save(s_proto); 72 prproto[1] = save(less_is_more ? more_proto : m_proto); 73 prproto[2] = save(M_proto); 74 eqproto = save(e_proto); 75 hproto = save(h_proto); 76 wproto = save(w_proto); 77 } 78 79 /* 80 * Append a string to the end of the message. 81 */ 82 static void 83 ap_str(char *s) 84 { 85 int len; 86 87 len = (int) strlen(s); 88 if (mp + len >= message + PROMPT_SIZE) 89 len = (int) (message + PROMPT_SIZE - mp - 1); 90 strncpy(mp, s, len); 91 mp += len; 92 *mp = '\0'; 93 } 94 95 /* 96 * Append a character to the end of the message. 97 */ 98 static void 99 ap_char(char c) 100 { 101 char buf[2]; 102 103 buf[0] = c; 104 buf[1] = '\0'; 105 ap_str(buf); 106 } 107 108 /* 109 * Append a POSITION (as a decimal integer) to the end of the message. 110 */ 111 static void 112 ap_pos(POSITION pos) 113 { 114 char buf[INT_STRLEN_BOUND(pos) + 2]; 115 116 postoa(pos, buf); 117 ap_str(buf); 118 } 119 120 /* 121 * Append a line number to the end of the message. 122 */ 123 static void 124 ap_linenum(LINENUM linenum) 125 { 126 char buf[INT_STRLEN_BOUND(linenum) + 2]; 127 128 linenumtoa(linenum, buf); 129 ap_str(buf); 130 } 131 132 /* 133 * Append an integer to the end of the message. 134 */ 135 static void 136 ap_int(int num) 137 { 138 char buf[INT_STRLEN_BOUND(num) + 2]; 139 140 inttoa(num, buf); 141 ap_str(buf); 142 } 143 144 /* 145 * Append a question mark to the end of the message. 146 */ 147 static void 148 ap_quest(void) 149 { 150 ap_str("?"); 151 } 152 153 /* 154 * Return the "current" byte offset in the file. 155 */ 156 static POSITION 157 curr_byte(int where) 158 { 159 POSITION pos; 160 161 pos = position(where); 162 while (pos == NULL_POSITION && where >= 0 && where < sc_height-1) 163 pos = position(++where); 164 if (pos == NULL_POSITION) 165 pos = ch_length(); 166 return (pos); 167 } 168 169 /* 170 * Return the value of a prototype conditional. 171 * A prototype string may include conditionals which consist of a 172 * question mark followed by a single letter. 173 * Here we decode that letter and return the appropriate boolean value. 174 */ 175 static int 176 cond(char c, int where) 177 { 178 POSITION len; 179 180 switch (c) 181 { 182 case 'a': /* Anything in the message yet? */ 183 return (mp > message); 184 case 'b': /* Current byte offset known? */ 185 return (curr_byte(where) != NULL_POSITION); 186 case 'c': 187 return (hshift != 0); 188 case 'e': /* At end of file? */ 189 return (eof_displayed()); 190 case 'f': /* Filename known? */ 191 return (strcmp(get_filename(curr_ifile), "-") != 0); 192 case 'l': /* Line number known? */ 193 case 'd': /* Same as l */ 194 return (linenums); 195 case 'L': /* Final line number known? */ 196 case 'D': /* Final page number known? */ 197 return (linenums && ch_length() != NULL_POSITION); 198 case 'm': /* More than one file? */ 199 #if TAGS 200 return (ntags() ? (ntags() > 1) : (nifile() > 1)); 201 #else 202 return (nifile() > 1); 203 #endif 204 case 'n': /* First prompt in a new file? */ 205 #if TAGS 206 return (ntags() ? 1 : new_file); 207 #else 208 return (new_file); 209 #endif 210 case 'p': /* Percent into file (bytes) known? */ 211 return (curr_byte(where) != NULL_POSITION && 212 ch_length() > 0); 213 case 'P': /* Percent into file (lines) known? */ 214 return (currline(where) != 0 && 215 (len = ch_length()) > 0 && 216 find_linenum(len) != 0); 217 case 's': /* Size of file known? */ 218 case 'B': 219 return (ch_length() != NULL_POSITION); 220 case 'x': /* Is there a "next" file? */ 221 #if TAGS 222 if (ntags()) 223 return (0); 224 #endif 225 return (next_ifile(curr_ifile) != NULL_IFILE); 226 } 227 return (0); 228 } 229 230 /* 231 * Decode a "percent" prototype character. 232 * A prototype string may include various "percent" escapes; 233 * that is, a percent sign followed by a single letter. 234 * Here we decode that letter and take the appropriate action, 235 * usually by appending something to the message being built. 236 */ 237 static void 238 protochar(int c, int where, int iseditproto) 239 { 240 POSITION pos; 241 POSITION len; 242 int n; 243 LINENUM linenum; 244 LINENUM last_linenum; 245 IFILE h; 246 247 #undef PAGE_NUM 248 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - 1)) + 1) 249 250 switch (c) 251 { 252 case 'b': /* Current byte offset */ 253 pos = curr_byte(where); 254 if (pos != NULL_POSITION) 255 ap_pos(pos); 256 else 257 ap_quest(); 258 break; 259 case 'c': 260 ap_int(hshift); 261 break; 262 case 'd': /* Current page number */ 263 linenum = currline(where); 264 if (linenum > 0 && sc_height > 1) 265 ap_linenum(PAGE_NUM(linenum)); 266 else 267 ap_quest(); 268 break; 269 case 'D': /* Final page number */ 270 /* Find the page number of the last byte in the file (len-1). */ 271 len = ch_length(); 272 if (len == NULL_POSITION) 273 ap_quest(); 274 else if (len == 0) 275 /* An empty file has no pages. */ 276 ap_linenum(0); 277 else 278 { 279 linenum = find_linenum(len - 1); 280 if (linenum <= 0) 281 ap_quest(); 282 else 283 ap_linenum(PAGE_NUM(linenum)); 284 } 285 break; 286 #if EDITOR 287 case 'E': /* Editor name */ 288 ap_str(editor); 289 break; 290 #endif 291 case 'f': /* File name */ 292 ap_str(get_filename(curr_ifile)); 293 break; 294 case 'F': /* Last component of file name */ 295 ap_str(last_component(get_filename(curr_ifile))); 296 break; 297 case 'i': /* Index into list of files */ 298 #if TAGS 299 if (ntags()) 300 ap_int(curr_tag()); 301 else 302 #endif 303 ap_int(get_index(curr_ifile)); 304 break; 305 case 'l': /* Current line number */ 306 linenum = currline(where); 307 if (linenum != 0) 308 ap_linenum(linenum); 309 else 310 ap_quest(); 311 break; 312 case 'L': /* Final line number */ 313 len = ch_length(); 314 if (len == NULL_POSITION || len == ch_zero() || 315 (linenum = find_linenum(len)) <= 0) 316 ap_quest(); 317 else 318 ap_linenum(linenum-1); 319 break; 320 case 'm': /* Number of files */ 321 #if TAGS 322 n = ntags(); 323 if (n) 324 ap_int(n); 325 else 326 #endif 327 ap_int(nifile()); 328 break; 329 case 'p': /* Percent into file (bytes) */ 330 pos = curr_byte(where); 331 len = ch_length(); 332 if (pos != NULL_POSITION && len > 0) 333 ap_int(percentage(pos,len)); 334 else 335 ap_quest(); 336 break; 337 case 'P': /* Percent into file (lines) */ 338 linenum = currline(where); 339 if (linenum == 0 || 340 (len = ch_length()) == NULL_POSITION || len == ch_zero() || 341 (last_linenum = find_linenum(len)) <= 0) 342 ap_quest(); 343 else 344 ap_int(percentage(linenum, last_linenum)); 345 break; 346 case 's': /* Size of file */ 347 case 'B': 348 len = ch_length(); 349 if (len != NULL_POSITION) 350 ap_pos(len); 351 else 352 ap_quest(); 353 break; 354 case 't': /* Truncate trailing spaces in the message */ 355 while (mp > message && mp[-1] == ' ') 356 mp--; 357 *mp = '\0'; 358 break; 359 case 'T': /* Type of list */ 360 #if TAGS 361 if (ntags()) 362 ap_str("tag"); 363 else 364 #endif 365 ap_str("file"); 366 break; 367 case 'x': /* Name of next file */ 368 h = next_ifile(curr_ifile); 369 if (h != NULL_IFILE) 370 ap_str(get_filename(h)); 371 else 372 ap_quest(); 373 break; 374 } 375 } 376 377 /* 378 * Skip a false conditional. 379 * When a false condition is found (either a false IF or the ELSE part 380 * of a true IF), this routine scans the prototype string to decide 381 * where to resume parsing the string. 382 * We must keep track of nested IFs and skip them properly. 383 */ 384 static constant char * 385 skipcond(constant char *p) 386 { 387 int iflevel; 388 389 /* 390 * We came in here after processing a ? or :, 391 * so we start nested one level deep. 392 */ 393 iflevel = 1; 394 395 for (;;) switch (*++p) 396 { 397 case '?': 398 /* 399 * Start of a nested IF. 400 */ 401 iflevel++; 402 break; 403 case ':': 404 /* 405 * Else. 406 * If this matches the IF we came in here with, 407 * then we're done. 408 */ 409 if (iflevel == 1) 410 return (p); 411 break; 412 case '.': 413 /* 414 * Endif. 415 * If this matches the IF we came in here with, 416 * then we're done. 417 */ 418 if (--iflevel == 0) 419 return (p); 420 break; 421 case '\\': 422 /* 423 * Backslash escapes the next character. 424 */ 425 ++p; 426 break; 427 case '\0': 428 /* 429 * Whoops. Hit end of string. 430 * This is a malformed conditional, but just treat it 431 * as if all active conditionals ends here. 432 */ 433 return (p-1); 434 } 435 /*NOTREACHED*/ 436 } 437 438 /* 439 * Decode a char that represents a position on the screen. 440 */ 441 static constant char * 442 wherechar(char constant *p, int *wp) 443 { 444 switch (*p) 445 { 446 case 'b': case 'd': case 'l': case 'p': case 'P': 447 switch (*++p) 448 { 449 case 't': *wp = TOP; break; 450 case 'm': *wp = MIDDLE; break; 451 case 'b': *wp = BOTTOM; break; 452 case 'B': *wp = BOTTOM_PLUS_ONE; break; 453 case 'j': *wp = adjsline(jump_sline); break; 454 default: *wp = TOP; p--; break; 455 } 456 } 457 return (p); 458 } 459 460 /* 461 * Construct a message based on a prototype string. 462 */ 463 public char * 464 pr_expand(constant char *proto, int maxwidth) 465 { 466 constant char *p; 467 int c; 468 int where; 469 470 mp = message; 471 472 if (*proto == '\0') 473 return (""); 474 475 for (p = proto; *p != '\0'; p++) 476 { 477 switch (*p) 478 { 479 default: /* Just put the character in the message */ 480 ap_char(*p); 481 break; 482 case '\\': /* Backslash escapes the next character */ 483 p++; 484 ap_char(*p); 485 break; 486 case '?': /* Conditional (IF) */ 487 if ((c = *++p) == '\0') 488 --p; 489 else 490 { 491 where = 0; 492 p = wherechar(p, &where); 493 if (!cond(c, where)) 494 p = skipcond(p); 495 } 496 break; 497 case ':': /* ELSE */ 498 p = skipcond(p); 499 break; 500 case '.': /* ENDIF */ 501 break; 502 case '%': /* Percent escape */ 503 if ((c = *++p) == '\0') 504 --p; 505 else 506 { 507 where = 0; 508 p = wherechar(p, &where); 509 protochar(c, where, 510 #if EDITOR 511 (proto == editproto)); 512 #else 513 0); 514 #endif 515 516 } 517 break; 518 } 519 } 520 521 if (mp == message) 522 return (""); 523 if (maxwidth > 0 && mp >= message + maxwidth) 524 { 525 /* 526 * Message is too long. 527 * Return just the final portion of it. 528 */ 529 return (mp - maxwidth); 530 } 531 return (message); 532 } 533 534 /* 535 * Return a message suitable for printing by the "=" command. 536 */ 537 public char * 538 eq_message(void) 539 { 540 return (pr_expand(eqproto, 0)); 541 } 542 543 /* 544 * Return a prompt. 545 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc. 546 * If we can't come up with an appropriate prompt, return NULL 547 * and the caller will prompt with a colon. 548 */ 549 public char * 550 pr_string(void) 551 { 552 char *prompt; 553 int type; 554 555 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1; 556 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ? 557 hproto : prproto[type], 558 sc_width-so_s_width-so_e_width-2); 559 new_file = 0; 560 return (prompt); 561 } 562 563 /* 564 * Return a message suitable for printing while waiting in the F command. 565 */ 566 public char * 567 wait_message(void) 568 { 569 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2)); 570 } 571