1 /* 2 * Copyright (C) 1984-2008 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 'i': /* Index into list of files */ 307 #if TAGS 308 if (ntags()) 309 ap_int(curr_tag()); 310 else 311 #endif 312 ap_int(get_index(curr_ifile)); 313 break; 314 case 'l': /* Current line number */ 315 linenum = currline(where); 316 if (linenum != 0) 317 ap_linenum(linenum); 318 else 319 ap_quest(); 320 break; 321 case 'L': /* Final line number */ 322 len = ch_length(); 323 if (len == NULL_POSITION || len == ch_zero() || 324 (linenum = find_linenum(len)) <= 0) 325 ap_quest(); 326 else 327 ap_linenum(linenum-1); 328 break; 329 case 'm': /* Number of files */ 330 #if TAGS 331 n = ntags(); 332 if (n) 333 ap_int(n); 334 else 335 #endif 336 ap_int(nifile()); 337 break; 338 case 'p': /* Percent into file (bytes) */ 339 pos = curr_byte(where); 340 len = ch_length(); 341 if (pos != NULL_POSITION && len > 0) 342 ap_int(percentage(pos,len)); 343 else 344 ap_quest(); 345 break; 346 case 'P': /* Percent into file (lines) */ 347 linenum = currline(where); 348 if (linenum == 0 || 349 (len = ch_length()) == NULL_POSITION || len == ch_zero() || 350 (last_linenum = find_linenum(len)) <= 0) 351 ap_quest(); 352 else 353 ap_int(percentage(linenum, last_linenum)); 354 break; 355 case 's': /* Size of file */ 356 case 'B': 357 len = ch_length(); 358 if (len != NULL_POSITION) 359 ap_pos(len); 360 else 361 ap_quest(); 362 break; 363 case 't': /* Truncate trailing spaces in the message */ 364 while (mp > message && mp[-1] == ' ') 365 mp--; 366 break; 367 case 'T': /* Type of list */ 368 #if TAGS 369 if (ntags()) 370 ap_str("tag"); 371 else 372 #endif 373 ap_str("file"); 374 break; 375 case 'x': /* Name of next file */ 376 h = next_ifile(curr_ifile); 377 if (h != NULL_IFILE) 378 ap_str(get_filename(h)); 379 else 380 ap_quest(); 381 break; 382 } 383 } 384 385 /* 386 * Skip a false conditional. 387 * When a false condition is found (either a false IF or the ELSE part 388 * of a true IF), this routine scans the prototype string to decide 389 * where to resume parsing the string. 390 * We must keep track of nested IFs and skip them properly. 391 */ 392 static char * 393 skipcond(p) 394 register char *p; 395 { 396 register int iflevel; 397 398 /* 399 * We came in here after processing a ? or :, 400 * so we start nested one level deep. 401 */ 402 iflevel = 1; 403 404 for (;;) switch (*++p) 405 { 406 case '?': 407 /* 408 * Start of a nested IF. 409 */ 410 iflevel++; 411 break; 412 case ':': 413 /* 414 * Else. 415 * If this matches the IF we came in here with, 416 * then we're done. 417 */ 418 if (iflevel == 1) 419 return (p); 420 break; 421 case '.': 422 /* 423 * Endif. 424 * If this matches the IF we came in here with, 425 * then we're done. 426 */ 427 if (--iflevel == 0) 428 return (p); 429 break; 430 case '\\': 431 /* 432 * Backslash escapes the next character. 433 */ 434 ++p; 435 break; 436 case '\0': 437 /* 438 * Whoops. Hit end of string. 439 * This is a malformed conditional, but just treat it 440 * as if all active conditionals ends here. 441 */ 442 return (p-1); 443 } 444 /*NOTREACHED*/ 445 } 446 447 /* 448 * Decode a char that represents a position on the screen. 449 */ 450 static char * 451 wherechar(p, wp) 452 char *p; 453 int *wp; 454 { 455 switch (*p) 456 { 457 case 'b': case 'd': case 'l': case 'p': case 'P': 458 switch (*++p) 459 { 460 case 't': *wp = TOP; break; 461 case 'm': *wp = MIDDLE; break; 462 case 'b': *wp = BOTTOM; break; 463 case 'B': *wp = BOTTOM_PLUS_ONE; break; 464 case 'j': *wp = adjsline(jump_sline); break; 465 default: *wp = TOP; p--; break; 466 } 467 } 468 return (p); 469 } 470 471 /* 472 * Construct a message based on a prototype string. 473 */ 474 public char * 475 pr_expand(proto, maxwidth) 476 char *proto; 477 int maxwidth; 478 { 479 register char *p; 480 register int c; 481 int where; 482 483 mp = message; 484 485 if (*proto == '\0') 486 return (""); 487 488 for (p = proto; *p != '\0'; p++) 489 { 490 switch (*p) 491 { 492 default: /* Just put the character in the message */ 493 ap_char(*p); 494 break; 495 case '\\': /* Backslash escapes the next character */ 496 p++; 497 ap_char(*p); 498 break; 499 case '?': /* Conditional (IF) */ 500 if ((c = *++p) == '\0') 501 --p; 502 else 503 { 504 where = 0; 505 p = wherechar(p, &where); 506 if (!cond(c, where)) 507 p = skipcond(p); 508 } 509 break; 510 case ':': /* ELSE */ 511 p = skipcond(p); 512 break; 513 case '.': /* ENDIF */ 514 break; 515 case '%': /* Percent escape */ 516 if ((c = *++p) == '\0') 517 --p; 518 else 519 { 520 where = 0; 521 p = wherechar(p, &where); 522 protochar(c, where, 523 #if EDITOR 524 (proto == editproto)); 525 #else 526 0); 527 #endif 528 529 } 530 break; 531 } 532 } 533 534 if (mp == message) 535 return (""); 536 if (maxwidth > 0 && mp >= message + maxwidth) 537 { 538 /* 539 * Message is too long. 540 * Return just the final portion of it. 541 */ 542 return (mp - maxwidth); 543 } 544 return (message); 545 } 546 547 /* 548 * Return a message suitable for printing by the "=" command. 549 */ 550 public char * 551 eq_message() 552 { 553 return (pr_expand(eqproto, 0)); 554 } 555 556 /* 557 * Return a prompt. 558 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc. 559 * If we can't come up with an appropriate prompt, return NULL 560 * and the caller will prompt with a colon. 561 */ 562 public char * 563 pr_string() 564 { 565 char *prompt; 566 int type; 567 568 type = (!less_is_more) ? pr_type : pr_type ? 0 : 1; 569 prompt = pr_expand((ch_getflags() & CH_HELPFILE) ? 570 hproto : prproto[type], 571 sc_width-so_s_width-so_e_width-2); 572 new_file = 0; 573 return (prompt); 574 } 575 576 /* 577 * Return a message suitable for printing while waiting in the F command. 578 */ 579 public char * 580 wait_message() 581 { 582 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2)); 583 } 584