1 /* 2 * Copyright (C) 1984-2017 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() 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() 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 return (strcmp(get_filename(curr_ifile), "-") != 0); 200 case 'l': /* Line number known? */ 201 case 'd': /* Same as l */ 202 return (linenums); 203 case 'L': /* Final line number known? */ 204 case 'D': /* Final page number known? */ 205 return (linenums && ch_length() != NULL_POSITION); 206 case 'm': /* More than one file? */ 207 #if TAGS 208 return (ntags() ? (ntags() > 1) : (nifile() > 1)); 209 #else 210 return (nifile() > 1); 211 #endif 212 case 'n': /* First prompt in a new file? */ 213 #if TAGS 214 return (ntags() ? 1 : new_file); 215 #else 216 return (new_file); 217 #endif 218 case 'p': /* Percent into file (bytes) known? */ 219 return (curr_byte(where) != NULL_POSITION && 220 ch_length() > 0); 221 case 'P': /* Percent into file (lines) known? */ 222 return (currline(where) != 0 && 223 (len = ch_length()) > 0 && 224 find_linenum(len) != 0); 225 case 's': /* Size of file known? */ 226 case 'B': 227 return (ch_length() != NULL_POSITION); 228 case 'x': /* Is there a "next" file? */ 229 #if TAGS 230 if (ntags()) 231 return (0); 232 #endif 233 return (next_ifile(curr_ifile) != NULL_IFILE); 234 } 235 return (0); 236 } 237 238 /* 239 * Decode a "percent" prototype character. 240 * A prototype string may include various "percent" escapes; 241 * that is, a percent sign followed by a single letter. 242 * Here we decode that letter and take the appropriate action, 243 * usually by appending something to the message being built. 244 */ 245 static void 246 protochar(c, where, iseditproto) 247 int c; 248 int where; 249 int iseditproto; 250 { 251 POSITION pos; 252 POSITION len; 253 int n; 254 LINENUM linenum; 255 LINENUM last_linenum; 256 IFILE h; 257 258 #undef PAGE_NUM 259 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - 1)) + 1) 260 261 switch (c) 262 { 263 case 'b': /* Current byte offset */ 264 pos = curr_byte(where); 265 if (pos != NULL_POSITION) 266 ap_pos(pos); 267 else 268 ap_quest(); 269 break; 270 case 'c': 271 ap_int(hshift); 272 break; 273 case 'd': /* Current page number */ 274 linenum = currline(where); 275 if (linenum > 0 && sc_height > 1) 276 ap_linenum(PAGE_NUM(linenum)); 277 else 278 ap_quest(); 279 break; 280 case 'D': /* Final page number */ 281 /* Find the page number of the last byte in the file (len-1). */ 282 len = ch_length(); 283 if (len == NULL_POSITION) 284 ap_quest(); 285 else if (len == 0) 286 /* An empty file has no pages. */ 287 ap_linenum(0); 288 else 289 { 290 linenum = find_linenum(len - 1); 291 if (linenum <= 0) 292 ap_quest(); 293 else 294 ap_linenum(PAGE_NUM(linenum)); 295 } 296 break; 297 #if EDITOR 298 case 'E': /* Editor name */ 299 ap_str(editor); 300 break; 301 #endif 302 case 'f': /* File name */ 303 ap_str(get_filename(curr_ifile)); 304 break; 305 case 'F': /* Last component of file name */ 306 ap_str(last_component(get_filename(curr_ifile))); 307 break; 308 case 'i': /* Index into list of files */ 309 #if TAGS 310 if (ntags()) 311 ap_int(curr_tag()); 312 else 313 #endif 314 ap_int(get_index(curr_ifile)); 315 break; 316 case 'l': /* Current line number */ 317 linenum = currline(where); 318 if (linenum != 0) 319 ap_linenum(linenum); 320 else 321 ap_quest(); 322 break; 323 case 'L': /* Final line number */ 324 len = ch_length(); 325 if (len == NULL_POSITION || len == ch_zero() || 326 (linenum = find_linenum(len)) <= 0) 327 ap_quest(); 328 else 329 ap_linenum(linenum-1); 330 break; 331 case 'm': /* Number of files */ 332 #if TAGS 333 n = ntags(); 334 if (n) 335 ap_int(n); 336 else 337 #endif 338 ap_int(nifile()); 339 break; 340 case 'p': /* Percent into file (bytes) */ 341 pos = curr_byte(where); 342 len = ch_length(); 343 if (pos != NULL_POSITION && len > 0) 344 ap_int(percentage(pos,len)); 345 else 346 ap_quest(); 347 break; 348 case 'P': /* Percent into file (lines) */ 349 linenum = currline(where); 350 if (linenum == 0 || 351 (len = ch_length()) == NULL_POSITION || len == ch_zero() || 352 (last_linenum = find_linenum(len)) <= 0) 353 ap_quest(); 354 else 355 ap_int(percentage(linenum, last_linenum)); 356 break; 357 case 's': /* Size of file */ 358 case 'B': 359 len = ch_length(); 360 if (len != NULL_POSITION) 361 ap_pos(len); 362 else 363 ap_quest(); 364 break; 365 case 't': /* Truncate trailing spaces in the message */ 366 while (mp > message && mp[-1] == ' ') 367 mp--; 368 *mp = '\0'; 369 break; 370 case 'T': /* Type of list */ 371 #if TAGS 372 if (ntags()) 373 ap_str("tag"); 374 else 375 #endif 376 ap_str("file"); 377 break; 378 case 'x': /* Name of next file */ 379 h = next_ifile(curr_ifile); 380 if (h != NULL_IFILE) 381 ap_str(get_filename(h)); 382 else 383 ap_quest(); 384 break; 385 } 386 } 387 388 /* 389 * Skip a false conditional. 390 * When a false condition is found (either a false IF or the ELSE part 391 * of a true IF), this routine scans the prototype string to decide 392 * where to resume parsing the string. 393 * We must keep track of nested IFs and skip them properly. 394 */ 395 static constant char * 396 skipcond(p) 397 constant char *p; 398 { 399 int iflevel; 400 401 /* 402 * We came in here after processing a ? or :, 403 * so we start nested one level deep. 404 */ 405 iflevel = 1; 406 407 for (;;) switch (*++p) 408 { 409 case '?': 410 /* 411 * Start of a nested IF. 412 */ 413 iflevel++; 414 break; 415 case ':': 416 /* 417 * Else. 418 * If this matches the IF we came in here with, 419 * then we're done. 420 */ 421 if (iflevel == 1) 422 return (p); 423 break; 424 case '.': 425 /* 426 * Endif. 427 * If this matches the IF we came in here with, 428 * then we're done. 429 */ 430 if (--iflevel == 0) 431 return (p); 432 break; 433 case '\\': 434 /* 435 * Backslash escapes the next character. 436 */ 437 ++p; 438 break; 439 case '\0': 440 /* 441 * Whoops. Hit end of string. 442 * This is a malformed conditional, but just treat it 443 * as if all active conditionals ends here. 444 */ 445 return (p-1); 446 } 447 /*NOTREACHED*/ 448 } 449 450 /* 451 * Decode a char that represents a position on the screen. 452 */ 453 static constant char * 454 wherechar(p, wp) 455 char constant *p; 456 int *wp; 457 { 458 switch (*p) 459 { 460 case 'b': case 'd': case 'l': case 'p': case 'P': 461 switch (*++p) 462 { 463 case 't': *wp = TOP; break; 464 case 'm': *wp = MIDDLE; break; 465 case 'b': *wp = BOTTOM; break; 466 case 'B': *wp = BOTTOM_PLUS_ONE; break; 467 case 'j': *wp = adjsline(jump_sline); break; 468 default: *wp = TOP; p--; break; 469 } 470 } 471 return (p); 472 } 473 474 /* 475 * Construct a message based on a prototype string. 476 */ 477 public char * 478 pr_expand(proto, maxwidth) 479 constant char *proto; 480 int maxwidth; 481 { 482 constant char *p; 483 int c; 484 int where; 485 486 mp = message; 487 488 if (*proto == '\0') 489 return (""); 490 491 for (p = proto; *p != '\0'; p++) 492 { 493 switch (*p) 494 { 495 default: /* Just put the character in the message */ 496 ap_char(*p); 497 break; 498 case '\\': /* Backslash escapes the next character */ 499 p++; 500 ap_char(*p); 501 break; 502 case '?': /* Conditional (IF) */ 503 if ((c = *++p) == '\0') 504 --p; 505 else 506 { 507 where = 0; 508 p = wherechar(p, &where); 509 if (!cond(c, where)) 510 p = skipcond(p); 511 } 512 break; 513 case ':': /* ELSE */ 514 p = skipcond(p); 515 break; 516 case '.': /* ENDIF */ 517 break; 518 case '%': /* Percent escape */ 519 if ((c = *++p) == '\0') 520 --p; 521 else 522 { 523 where = 0; 524 p = wherechar(p, &where); 525 protochar(c, where, 526 #if EDITOR 527 (proto == editproto)); 528 #else 529 0); 530 #endif 531 532 } 533 break; 534 } 535 } 536 537 if (mp == message) 538 return (""); 539 if (maxwidth > 0 && mp >= message + maxwidth) 540 { 541 /* 542 * Message is too long. 543 * Return just the final portion of it. 544 */ 545 return (mp - maxwidth); 546 } 547 return (message); 548 } 549 550 /* 551 * Return a message suitable for printing by the "=" command. 552 */ 553 public char * 554 eq_message() 555 { 556 return (pr_expand(eqproto, 0)); 557 } 558 559 /* 560 * Return a prompt. 561 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc. 562 * If we can't come up with an appropriate prompt, return NULL 563 * and the caller will prompt with a colon. 564 */ 565 public char * 566 pr_string() 567 { 568 char *prompt; 569 int type; 570 571 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1; 572 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ? 573 hproto : prproto[type], 574 sc_width-so_s_width-so_e_width-2); 575 new_file = 0; 576 return (prompt); 577 } 578 579 /* 580 * Return a message suitable for printing while waiting in the F command. 581 */ 582 public char * 583 wait_message() 584 { 585 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2)); 586 } 587