1 /* 2 * Copyright (C) 1984-2021 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_PARAM) 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(s) 84 char *s; 85 { 86 int len; 87 88 len = (int) strlen(s); 89 if (mp + len >= message + PROMPT_SIZE) 90 len = (int) (message + PROMPT_SIZE - mp - 1); 91 strncpy(mp, s, len); 92 mp += len; 93 *mp = '\0'; 94 } 95 96 /* 97 * Append a character to the end of the message. 98 */ 99 static void 100 ap_char(c) 101 char c; 102 { 103 char buf[2]; 104 105 buf[0] = c; 106 buf[1] = '\0'; 107 ap_str(buf); 108 } 109 110 /* 111 * Append a POSITION (as a decimal integer) to the end of the message. 112 */ 113 static void 114 ap_pos(pos) 115 POSITION pos; 116 { 117 char buf[INT_STRLEN_BOUND(pos) + 2]; 118 119 postoa(pos, buf); 120 ap_str(buf); 121 } 122 123 /* 124 * Append a line number to the end of the message. 125 */ 126 static void 127 ap_linenum(linenum) 128 LINENUM linenum; 129 { 130 char buf[INT_STRLEN_BOUND(linenum) + 2]; 131 132 linenumtoa(linenum, buf); 133 ap_str(buf); 134 } 135 136 /* 137 * Append an integer to the end of the message. 138 */ 139 static void 140 ap_int(num) 141 int num; 142 { 143 char buf[INT_STRLEN_BOUND(num) + 2]; 144 145 inttoa(num, buf); 146 ap_str(buf); 147 } 148 149 /* 150 * Append a question mark to the end of the message. 151 */ 152 static void 153 ap_quest(VOID_PARAM) 154 { 155 ap_str("?"); 156 } 157 158 /* 159 * Return the "current" byte offset in the file. 160 */ 161 static POSITION 162 curr_byte(where) 163 int where; 164 { 165 POSITION pos; 166 167 pos = position(where); 168 while (pos == NULL_POSITION && where >= 0 && where < sc_height-1) 169 pos = position(++where); 170 if (pos == NULL_POSITION) 171 pos = ch_length(); 172 return (pos); 173 } 174 175 /* 176 * Return the value of a prototype conditional. 177 * A prototype string may include conditionals which consist of a 178 * question mark followed by a single letter. 179 * Here we decode that letter and return the appropriate boolean value. 180 */ 181 static int 182 cond(c, where) 183 char c; 184 int where; 185 { 186 POSITION len; 187 188 switch (c) 189 { 190 case 'a': /* Anything in the message yet? */ 191 return (mp > message); 192 case 'b': /* Current byte offset known? */ 193 return (curr_byte(where) != NULL_POSITION); 194 case 'c': 195 return (hshift != 0); 196 case 'e': /* At end of file? */ 197 return (eof_displayed()); 198 case 'f': /* Filename known? */ 199 case 'g': 200 return (strcmp(get_filename(curr_ifile), "-") != 0); 201 case 'l': /* Line number known? */ 202 case 'd': /* Same as l */ 203 if (!linenums) 204 return 0; 205 return (currline(where) != 0); 206 case 'L': /* Final line number known? */ 207 case 'D': /* Final page number known? */ 208 return (linenums && ch_length() != NULL_POSITION); 209 case 'm': /* More than one file? */ 210 #if TAGS 211 return (ntags() ? (ntags() > 1) : (nifile() > 1)); 212 #else 213 return (nifile() > 1); 214 #endif 215 case 'n': /* First prompt in a new file? */ 216 #if TAGS 217 return (ntags() ? 1 : new_file); 218 #else 219 return (new_file); 220 #endif 221 case 'p': /* Percent into file (bytes) known? */ 222 return (curr_byte(where) != NULL_POSITION && 223 ch_length() > 0); 224 case 'P': /* Percent into file (lines) known? */ 225 return (currline(where) != 0 && 226 (len = ch_length()) > 0 && 227 find_linenum(len) != 0); 228 case 's': /* Size of file known? */ 229 case 'B': 230 return (ch_length() != NULL_POSITION); 231 case 'x': /* Is there a "next" file? */ 232 #if TAGS 233 if (ntags()) 234 return (0); 235 #endif 236 return (next_ifile(curr_ifile) != NULL_IFILE); 237 } 238 return (0); 239 } 240 241 /* 242 * Decode a "percent" prototype character. 243 * A prototype string may include various "percent" escapes; 244 * that is, a percent sign followed by a single letter. 245 * Here we decode that letter and take the appropriate action, 246 * usually by appending something to the message being built. 247 */ 248 static void 249 protochar(c, where, iseditproto) 250 int c; 251 int where; 252 int iseditproto; 253 { 254 POSITION pos; 255 POSITION len; 256 int n; 257 LINENUM linenum; 258 LINENUM last_linenum; 259 IFILE h; 260 char *s; 261 262 #undef PAGE_NUM 263 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - 1)) + 1) 264 265 switch (c) 266 { 267 case 'b': /* Current byte offset */ 268 pos = curr_byte(where); 269 if (pos != NULL_POSITION) 270 ap_pos(pos); 271 else 272 ap_quest(); 273 break; 274 case 'c': 275 ap_int(hshift); 276 break; 277 case 'd': /* Current page number */ 278 linenum = currline(where); 279 if (linenum > 0 && sc_height > 1) 280 ap_linenum(PAGE_NUM(linenum)); 281 else 282 ap_quest(); 283 break; 284 case 'D': /* Final page number */ 285 /* Find the page number of the last byte in the file (len-1). */ 286 len = ch_length(); 287 if (len == NULL_POSITION) 288 ap_quest(); 289 else if (len == 0) 290 /* An empty file has no pages. */ 291 ap_linenum(0); 292 else 293 { 294 linenum = find_linenum(len - 1); 295 if (linenum <= 0) 296 ap_quest(); 297 else 298 ap_linenum(PAGE_NUM(linenum)); 299 } 300 break; 301 #if EDITOR 302 case 'E': /* Editor name */ 303 ap_str(editor); 304 break; 305 #endif 306 case 'f': /* File name */ 307 ap_str(get_filename(curr_ifile)); 308 break; 309 case 'F': /* Last component of file name */ 310 ap_str(last_component(get_filename(curr_ifile))); 311 break; 312 case 'g': /* Shell-escaped file name */ 313 s = shell_quote(get_filename(curr_ifile)); 314 ap_str(s); 315 free(s); 316 break; 317 case 'i': /* Index into list of files */ 318 #if TAGS 319 if (ntags()) 320 ap_int(curr_tag()); 321 else 322 #endif 323 ap_int(get_index(curr_ifile)); 324 break; 325 case 'l': /* Current line number */ 326 linenum = currline(where); 327 if (linenum != 0) 328 ap_linenum(linenum); 329 else 330 ap_quest(); 331 break; 332 case 'L': /* Final line number */ 333 len = ch_length(); 334 if (len == NULL_POSITION || len == ch_zero() || 335 (linenum = find_linenum(len)) <= 0) 336 ap_quest(); 337 else 338 ap_linenum(linenum-1); 339 break; 340 case 'm': /* Number of files */ 341 #if TAGS 342 n = ntags(); 343 if (n) 344 ap_int(n); 345 else 346 #endif 347 ap_int(nifile()); 348 break; 349 case 'p': /* Percent into file (bytes) */ 350 pos = curr_byte(where); 351 len = ch_length(); 352 if (pos != NULL_POSITION && len > 0) 353 ap_int(percentage(pos,len)); 354 else 355 ap_quest(); 356 break; 357 case 'P': /* Percent into file (lines) */ 358 linenum = currline(where); 359 if (linenum == 0 || 360 (len = ch_length()) == NULL_POSITION || len == ch_zero() || 361 (last_linenum = find_linenum(len)) <= 0) 362 ap_quest(); 363 else 364 ap_int(percentage(linenum, last_linenum)); 365 break; 366 case 's': /* Size of file */ 367 case 'B': 368 len = ch_length(); 369 if (len != NULL_POSITION) 370 ap_pos(len); 371 else 372 ap_quest(); 373 break; 374 case 't': /* Truncate trailing spaces in the message */ 375 while (mp > message && mp[-1] == ' ') 376 mp--; 377 *mp = '\0'; 378 break; 379 case 'T': /* Type of list */ 380 #if TAGS 381 if (ntags()) 382 ap_str("tag"); 383 else 384 #endif 385 ap_str("file"); 386 break; 387 case 'x': /* Name of next file */ 388 h = next_ifile(curr_ifile); 389 if (h != NULL_IFILE) 390 ap_str(get_filename(h)); 391 else 392 ap_quest(); 393 break; 394 } 395 } 396 397 /* 398 * Skip a false conditional. 399 * When a false condition is found (either a false IF or the ELSE part 400 * of a true IF), this routine scans the prototype string to decide 401 * where to resume parsing the string. 402 * We must keep track of nested IFs and skip them properly. 403 */ 404 static constant char * 405 skipcond(p) 406 constant char *p; 407 { 408 int iflevel; 409 410 /* 411 * We came in here after processing a ? or :, 412 * so we start nested one level deep. 413 */ 414 iflevel = 1; 415 416 for (;;) switch (*++p) 417 { 418 case '?': 419 /* 420 * Start of a nested IF. 421 */ 422 iflevel++; 423 break; 424 case ':': 425 /* 426 * Else. 427 * If this matches the IF we came in here with, 428 * then we're done. 429 */ 430 if (iflevel == 1) 431 return (p); 432 break; 433 case '.': 434 /* 435 * Endif. 436 * If this matches the IF we came in here with, 437 * then we're done. 438 */ 439 if (--iflevel == 0) 440 return (p); 441 break; 442 case '\\': 443 /* 444 * Backslash escapes the next character. 445 */ 446 ++p; 447 break; 448 case '\0': 449 /* 450 * Whoops. Hit end of string. 451 * This is a malformed conditional, but just treat it 452 * as if all active conditionals ends here. 453 */ 454 return (p-1); 455 } 456 /*NOTREACHED*/ 457 } 458 459 /* 460 * Decode a char that represents a position on the screen. 461 */ 462 static constant char * 463 wherechar(p, wp) 464 char constant *p; 465 int *wp; 466 { 467 switch (*p) 468 { 469 case 'b': case 'd': case 'l': case 'p': case 'P': 470 switch (*++p) 471 { 472 case 't': *wp = TOP; break; 473 case 'm': *wp = MIDDLE; break; 474 case 'b': *wp = BOTTOM; break; 475 case 'B': *wp = BOTTOM_PLUS_ONE; break; 476 case 'j': *wp = sindex_from_sline(jump_sline); break; 477 default: *wp = TOP; p--; break; 478 } 479 } 480 return (p); 481 } 482 483 /* 484 * Construct a message based on a prototype string. 485 */ 486 public char * 487 pr_expand(proto, maxwidth) 488 constant char *proto; 489 int maxwidth; 490 { 491 constant char *p; 492 int c; 493 int where; 494 495 mp = message; 496 497 if (*proto == '\0') 498 return (""); 499 500 for (p = proto; *p != '\0'; p++) 501 { 502 switch (*p) 503 { 504 default: /* Just put the character in the message */ 505 ap_char(*p); 506 break; 507 case '\\': /* Backslash escapes the next character */ 508 p++; 509 ap_char(*p); 510 break; 511 case '?': /* Conditional (IF) */ 512 if ((c = *++p) == '\0') 513 --p; 514 else 515 { 516 where = 0; 517 p = wherechar(p, &where); 518 if (!cond(c, where)) 519 p = skipcond(p); 520 } 521 break; 522 case ':': /* ELSE */ 523 p = skipcond(p); 524 break; 525 case '.': /* ENDIF */ 526 break; 527 case '%': /* Percent escape */ 528 if ((c = *++p) == '\0') 529 --p; 530 else 531 { 532 where = 0; 533 p = wherechar(p, &where); 534 protochar(c, where, 535 #if EDITOR 536 (proto == editproto)); 537 #else 538 0); 539 #endif 540 541 } 542 break; 543 } 544 } 545 546 if (mp == message) 547 return (""); 548 if (maxwidth > 0 && mp >= message + maxwidth) 549 { 550 /* 551 * Message is too long. 552 * Return just the final portion of it. 553 */ 554 return (mp - maxwidth); 555 } 556 return (message); 557 } 558 559 /* 560 * Return a message suitable for printing by the "=" command. 561 */ 562 public char * 563 eq_message(VOID_PARAM) 564 { 565 return (pr_expand(eqproto, 0)); 566 } 567 568 /* 569 * Return a prompt. 570 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc. 571 * If we can't come up with an appropriate prompt, return NULL 572 * and the caller will prompt with a colon. 573 */ 574 public char * 575 pr_string(VOID_PARAM) 576 { 577 char *prompt; 578 int type; 579 580 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1; 581 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ? 582 hproto : prproto[type], 583 sc_width-so_s_width-so_e_width-2); 584 new_file = 0; 585 return (prompt); 586 } 587 588 /* 589 * Return a message suitable for printing while waiting in the F command. 590 */ 591 public char * 592 wait_message(VOID_PARAM) 593 { 594 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2)); 595 } 596