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