1 /* 2 * Copyright (C) 1984-2011 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 about less, or for information on how to 8 * contact the author, see the README file. 9 */ 10 11 12 /* 13 * Prompting and other messages. 14 * There are three flavors of prompts, SHORT, MEDIUM and LONG, 15 * selected by the -m/-M options. 16 * There is also the "equals message", printed by the = command. 17 * A prompt is a message composed of various pieces, such as the 18 * name of the file being viewed, the percentage into the file, etc. 19 */ 20 21 #include "less.h" 22 #include "position.h" 23 24 extern int pr_type; 25 extern int new_file; 26 extern int sc_width; 27 extern int so_s_width, so_e_width; 28 extern int linenums; 29 extern int hshift; 30 extern int sc_height; 31 extern int jump_sline; 32 extern int less_is_more; 33 extern IFILE curr_ifile; 34 #if EDITOR 35 extern char *editor; 36 extern char *editproto; 37 #endif 38 39 /* 40 * Prototypes for the three flavors of prompts. 41 * These strings are expanded by pr_expand(). 42 */ 43 static constant char s_proto[] = 44 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t"; 45 static constant char m_proto[] = 46 "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t"; 47 static constant char M_proto[] = 48 "?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"; 49 static constant char e_proto[] = 50 "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t"; 51 static constant char h_proto[] = 52 "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done"; 53 static constant char w_proto[] = 54 "Waiting for data"; 55 static constant char more_proto[] = 56 "--More--(?eEND ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t)"; 57 58 public char *prproto[3]; 59 public char constant *eqproto = e_proto; 60 public char constant *hproto = h_proto; 61 public char constant *wproto = w_proto; 62 63 static char message[PROMPT_SIZE]; 64 static char *mp; 65 66 /* 67 * Initialize the prompt prototype strings. 68 */ 69 public void 70 init_prompt() 71 { 72 prproto[0] = save(s_proto); 73 prproto[1] = save(less_is_more ? more_proto : m_proto); 74 prproto[2] = save(M_proto); 75 eqproto = save(e_proto); 76 hproto = save(h_proto); 77 wproto = save(w_proto); 78 } 79 80 /* 81 * Append a string to the end of the message. 82 */ 83 static void 84 ap_str(s) 85 char *s; 86 { 87 int len; 88 89 len = strlen(s); 90 if (mp + len >= message + PROMPT_SIZE) 91 len = message + PROMPT_SIZE - mp - 1; 92 strncpy(mp, s, len); 93 mp += len; 94 *mp = '\0'; 95 } 96 97 /* 98 * Append a character to the end of the message. 99 */ 100 static void 101 ap_char(c) 102 char c; 103 { 104 char buf[2]; 105 106 buf[0] = c; 107 buf[1] = '\0'; 108 ap_str(buf); 109 } 110 111 /* 112 * Append a POSITION (as a decimal integer) to the end of the message. 113 */ 114 static void 115 ap_pos(pos) 116 POSITION pos; 117 { 118 char buf[INT_STRLEN_BOUND(pos) + 2]; 119 120 postoa(pos, buf); 121 ap_str(buf); 122 } 123 124 /* 125 * Append a line number to the end of the message. 126 */ 127 static void 128 ap_linenum(linenum) 129 LINENUM linenum; 130 { 131 char buf[INT_STRLEN_BOUND(linenum) + 2]; 132 133 linenumtoa(linenum, buf); 134 ap_str(buf); 135 } 136 137 /* 138 * Append an integer to the end of the message. 139 */ 140 static void 141 ap_int(num) 142 int num; 143 { 144 char buf[INT_STRLEN_BOUND(num) + 2]; 145 146 inttoa(num, buf); 147 ap_str(buf); 148 } 149 150 /* 151 * Append a question mark to the end of the message. 152 */ 153 static void 154 ap_quest() 155 { 156 ap_str("?"); 157 } 158 159 /* 160 * Return the "current" byte offset in the file. 161 */ 162 static POSITION 163 curr_byte(where) 164 int where; 165 { 166 POSITION pos; 167 168 pos = position(where); 169 while (pos == NULL_POSITION && where >= 0 && where < sc_height-1) 170 pos = position(++where); 171 if (pos == NULL_POSITION) 172 pos = ch_length(); 173 return (pos); 174 } 175 176 /* 177 * Return the value of a prototype conditional. 178 * A prototype string may include conditionals which consist of a 179 * question mark followed by a single letter. 180 * Here we decode that letter and return the appropriate boolean value. 181 */ 182 static int 183 cond(c, where) 184 char c; 185 int where; 186 { 187 POSITION len; 188 189 switch (c) 190 { 191 case 'a': /* Anything in the message yet? */ 192 return (mp > message); 193 case 'b': /* Current byte offset known? */ 194 return (curr_byte(where) != NULL_POSITION); 195 case 'c': 196 return (hshift != 0); 197 case 'e': /* At end of file? */ 198 return (eof_displayed()); 199 case 'f': /* Filename known? */ 200 return (strcmp(get_filename(curr_ifile), "-") != 0); 201 case 'l': /* Line number known? */ 202 case 'd': /* Same as l */ 203 return (linenums); 204 case 'L': /* Final line number known? */ 205 case 'D': /* Final page number known? */ 206 return (linenums && ch_length() != NULL_POSITION); 207 case 'm': /* More than one file? */ 208 #if TAGS 209 return (ntags() ? (ntags() > 1) : (nifile() > 1)); 210 #else 211 return (nifile() > 1); 212 #endif 213 case 'n': /* First prompt in a new file? */ 214 #if TAGS 215 return (ntags() ? 1 : new_file); 216 #else 217 return (new_file); 218 #endif 219 case 'p': /* Percent into file (bytes) known? */ 220 return (curr_byte(where) != NULL_POSITION && 221 ch_length() > 0); 222 case 'P': /* Percent into file (lines) known? */ 223 return (currline(where) != 0 && 224 (len = ch_length()) > 0 && 225 find_linenum(len) != 0); 226 case 's': /* Size of file known? */ 227 case 'B': 228 return (ch_length() != NULL_POSITION); 229 case 'x': /* Is there a "next" file? */ 230 #if TAGS 231 if (ntags()) 232 return (0); 233 #endif 234 return (next_ifile(curr_ifile) != NULL_IFILE); 235 } 236 return (0); 237 } 238 239 /* 240 * Decode a "percent" prototype character. 241 * A prototype string may include various "percent" escapes; 242 * that is, a percent sign followed by a single letter. 243 * Here we decode that letter and take the appropriate action, 244 * usually by appending something to the message being built. 245 */ 246 static void 247 protochar(c, where, iseditproto) 248 int c; 249 int where; 250 int iseditproto; 251 { 252 POSITION pos; 253 POSITION len; 254 int n; 255 LINENUM linenum; 256 LINENUM last_linenum; 257 IFILE h; 258 259 #undef PAGE_NUM 260 #define PAGE_NUM(linenum) ((((linenum) - 1) / (sc_height - 1)) + 1) 261 262 switch (c) 263 { 264 case 'b': /* Current byte offset */ 265 pos = curr_byte(where); 266 if (pos != NULL_POSITION) 267 ap_pos(pos); 268 else 269 ap_quest(); 270 break; 271 case 'c': 272 ap_int(hshift); 273 break; 274 case 'd': /* Current page number */ 275 linenum = currline(where); 276 if (linenum > 0 && sc_height > 1) 277 ap_linenum(PAGE_NUM(linenum)); 278 else 279 ap_quest(); 280 break; 281 case 'D': /* Final page number */ 282 /* Find the page number of the last byte in the file (len-1). */ 283 len = ch_length(); 284 if (len == NULL_POSITION) 285 ap_quest(); 286 else if (len == 0) 287 /* An empty file has no pages. */ 288 ap_linenum(0); 289 else 290 { 291 linenum = find_linenum(len - 1); 292 if (linenum <= 0) 293 ap_quest(); 294 else 295 ap_linenum(PAGE_NUM(linenum)); 296 } 297 break; 298 #if EDITOR 299 case 'E': /* Editor name */ 300 ap_str(editor); 301 break; 302 #endif 303 case 'f': /* File name */ 304 ap_str(get_filename(curr_ifile)); 305 break; 306 case 'F': /* Last component of file name */ 307 ap_str(last_component(get_filename(curr_ifile))); 308 break; 309 case 'i': /* Index into list of files */ 310 #if TAGS 311 if (ntags()) 312 ap_int(curr_tag()); 313 else 314 #endif 315 ap_int(get_index(curr_ifile)); 316 break; 317 case 'l': /* Current line number */ 318 linenum = currline(where); 319 if (linenum != 0) 320 ap_linenum(linenum); 321 else 322 ap_quest(); 323 break; 324 case 'L': /* Final line number */ 325 len = ch_length(); 326 if (len == NULL_POSITION || len == ch_zero() || 327 (linenum = find_linenum(len)) <= 0) 328 ap_quest(); 329 else 330 ap_linenum(linenum-1); 331 break; 332 case 'm': /* Number of files */ 333 #if TAGS 334 n = ntags(); 335 if (n) 336 ap_int(n); 337 else 338 #endif 339 ap_int(nifile()); 340 break; 341 case 'p': /* Percent into file (bytes) */ 342 pos = curr_byte(where); 343 len = ch_length(); 344 if (pos != NULL_POSITION && len > 0) 345 ap_int(percentage(pos,len)); 346 else 347 ap_quest(); 348 break; 349 case 'P': /* Percent into file (lines) */ 350 linenum = currline(where); 351 if (linenum == 0 || 352 (len = ch_length()) == NULL_POSITION || len == ch_zero() || 353 (last_linenum = find_linenum(len)) <= 0) 354 ap_quest(); 355 else 356 ap_int(percentage(linenum, last_linenum)); 357 break; 358 case 's': /* Size of file */ 359 case 'B': 360 len = ch_length(); 361 if (len != NULL_POSITION) 362 ap_pos(len); 363 else 364 ap_quest(); 365 break; 366 case 't': /* Truncate trailing spaces in the message */ 367 while (mp > message && mp[-1] == ' ') 368 mp--; 369 *mp = '\0'; 370 break; 371 case 'T': /* Type of list */ 372 #if TAGS 373 if (ntags()) 374 ap_str("tag"); 375 else 376 #endif 377 ap_str("file"); 378 break; 379 case 'x': /* Name of next file */ 380 h = next_ifile(curr_ifile); 381 if (h != NULL_IFILE) 382 ap_str(get_filename(h)); 383 else 384 ap_quest(); 385 break; 386 } 387 } 388 389 /* 390 * Skip a false conditional. 391 * When a false condition is found (either a false IF or the ELSE part 392 * of a true IF), this routine scans the prototype string to decide 393 * where to resume parsing the string. 394 * We must keep track of nested IFs and skip them properly. 395 */ 396 static char * 397 skipcond(p) 398 register char *p; 399 { 400 register int iflevel; 401 402 /* 403 * We came in here after processing a ? or :, 404 * so we start nested one level deep. 405 */ 406 iflevel = 1; 407 408 for (;;) switch (*++p) 409 { 410 case '?': 411 /* 412 * Start of a nested IF. 413 */ 414 iflevel++; 415 break; 416 case ':': 417 /* 418 * Else. 419 * If this matches the IF we came in here with, 420 * then we're done. 421 */ 422 if (iflevel == 1) 423 return (p); 424 break; 425 case '.': 426 /* 427 * Endif. 428 * If this matches the IF we came in here with, 429 * then we're done. 430 */ 431 if (--iflevel == 0) 432 return (p); 433 break; 434 case '\\': 435 /* 436 * Backslash escapes the next character. 437 */ 438 ++p; 439 break; 440 case '\0': 441 /* 442 * Whoops. Hit end of string. 443 * This is a malformed conditional, but just treat it 444 * as if all active conditionals ends here. 445 */ 446 return (p-1); 447 } 448 /*NOTREACHED*/ 449 } 450 451 /* 452 * Decode a char that represents a position on the screen. 453 */ 454 static char * 455 wherechar(p, wp) 456 char *p; 457 int *wp; 458 { 459 switch (*p) 460 { 461 case 'b': case 'd': case 'l': case 'p': case 'P': 462 switch (*++p) 463 { 464 case 't': *wp = TOP; break; 465 case 'm': *wp = MIDDLE; break; 466 case 'b': *wp = BOTTOM; break; 467 case 'B': *wp = BOTTOM_PLUS_ONE; break; 468 case 'j': *wp = adjsline(jump_sline); break; 469 default: *wp = TOP; p--; break; 470 } 471 } 472 return (p); 473 } 474 475 /* 476 * Construct a message based on a prototype string. 477 */ 478 public char * 479 pr_expand(proto, maxwidth) 480 char *proto; 481 int maxwidth; 482 { 483 register char *p; 484 register int c; 485 int where; 486 487 mp = message; 488 489 if (*proto == '\0') 490 return (""); 491 492 for (p = proto; *p != '\0'; p++) 493 { 494 switch (*p) 495 { 496 default: /* Just put the character in the message */ 497 ap_char(*p); 498 break; 499 case '\\': /* Backslash escapes the next character */ 500 p++; 501 ap_char(*p); 502 break; 503 case '?': /* Conditional (IF) */ 504 if ((c = *++p) == '\0') 505 --p; 506 else 507 { 508 where = 0; 509 p = wherechar(p, &where); 510 if (!cond(c, where)) 511 p = skipcond(p); 512 } 513 break; 514 case ':': /* ELSE */ 515 p = skipcond(p); 516 break; 517 case '.': /* ENDIF */ 518 break; 519 case '%': /* Percent escape */ 520 if ((c = *++p) == '\0') 521 --p; 522 else 523 { 524 where = 0; 525 p = wherechar(p, &where); 526 protochar(c, where, 527 #if EDITOR 528 (proto == editproto)); 529 #else 530 0); 531 #endif 532 533 } 534 break; 535 } 536 } 537 538 if (mp == message) 539 return (""); 540 if (maxwidth > 0 && mp >= message + maxwidth) 541 { 542 /* 543 * Message is too long. 544 * Return just the final portion of it. 545 */ 546 return (mp - maxwidth); 547 } 548 return (message); 549 } 550 551 /* 552 * Return a message suitable for printing by the "=" command. 553 */ 554 public char * 555 eq_message() 556 { 557 return (pr_expand(eqproto, 0)); 558 } 559 560 /* 561 * Return a prompt. 562 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc. 563 * If we can't come up with an appropriate prompt, return NULL 564 * and the caller will prompt with a colon. 565 */ 566 public char * 567 pr_string() 568 { 569 char *prompt; 570 int type; 571 572 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1; 573 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ? 574 hproto : prproto[type], 575 sc_width-so_s_width-so_e_width-2); 576 new_file = 0; 577 return (prompt); 578 } 579 580 /* 581 * Return a message suitable for printing while waiting in the F command. 582 */ 583 public char * 584 wait_message() 585 { 586 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2)); 587 } 588