1 /* 2 * Copyright (C) 1984-2002 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 hit_eof; 26 extern int new_file; 27 extern int sc_width; 28 extern int so_s_width, so_e_width; 29 extern int linenums; 30 extern int hshift; 31 extern int sc_height; 32 extern int jump_sline; 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) 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 (hit_eof); 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': /* Same as L */ 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 switch (c) 258 { 259 case 'b': /* Current byte offset */ 260 pos = curr_byte(where); 261 if (pos != NULL_POSITION) 262 ap_pos(pos); 263 else 264 ap_quest(); 265 break; 266 case 'c': 267 ap_int(hshift); 268 break; 269 case 'd': /* Current page number */ 270 linenum = currline(where); 271 if (linenum > 0 && sc_height > 1) 272 ap_linenum(((linenum - 1) / (sc_height - 1)) + 1); 273 else 274 ap_quest(); 275 break; 276 case 'D': /* Last page number */ 277 len = ch_length(); 278 if (len == NULL_POSITION || len == ch_zero() || 279 (linenum = find_linenum(len)) <= 0) 280 ap_quest(); 281 else 282 ap_linenum(((linenum - 1) / (sc_height - 1)) + 1); 283 break; 284 #if EDITOR 285 case 'E': /* Editor name */ 286 ap_str(editor); 287 break; 288 #endif 289 case 'f': /* File name */ 290 ap_str(get_filename(curr_ifile)); 291 break; 292 case 'i': /* Index into list of files */ 293 #if TAGS 294 if (ntags()) 295 ap_int(curr_tag()); 296 else 297 #endif 298 ap_int(get_index(curr_ifile)); 299 break; 300 case 'l': /* Current line number */ 301 linenum = currline(where); 302 if (linenum != 0) 303 ap_linenum(linenum); 304 else 305 ap_quest(); 306 break; 307 case 'L': /* Final line number */ 308 len = ch_length(); 309 if (len == NULL_POSITION || len == ch_zero() || 310 (linenum = find_linenum(len)) <= 0) 311 ap_quest(); 312 else 313 ap_linenum(linenum-1); 314 break; 315 case 'm': /* Number of files */ 316 #if TAGS 317 n = ntags(); 318 if (n) 319 ap_int(n); 320 else 321 #endif 322 ap_int(nifile()); 323 break; 324 case 'p': /* Percent into file (bytes) */ 325 pos = curr_byte(where); 326 len = ch_length(); 327 if (pos != NULL_POSITION && len > 0) 328 ap_int(percentage(pos,len)); 329 else 330 ap_quest(); 331 break; 332 case 'P': /* Percent into file (lines) */ 333 linenum = currline(where); 334 if (linenum == 0 || 335 (len = ch_length()) == NULL_POSITION || len == ch_zero() || 336 (last_linenum = find_linenum(len)) <= 0) 337 ap_quest(); 338 else 339 ap_int(percentage(linenum, last_linenum)); 340 break; 341 case 's': /* Size of file */ 342 case 'B': 343 len = ch_length(); 344 if (len != NULL_POSITION) 345 ap_pos(len); 346 else 347 ap_quest(); 348 break; 349 case 't': /* Truncate trailing spaces in the message */ 350 while (mp > message && mp[-1] == ' ') 351 mp--; 352 break; 353 case 'T': /* Type of list */ 354 #if TAGS 355 if (ntags()) 356 ap_str("tag"); 357 else 358 #endif 359 ap_str("file"); 360 break; 361 case 'x': /* Name of next file */ 362 h = next_ifile(curr_ifile); 363 if (h != NULL_IFILE) 364 ap_str(get_filename(h)); 365 else 366 ap_quest(); 367 break; 368 } 369 } 370 371 /* 372 * Skip a false conditional. 373 * When a false condition is found (either a false IF or the ELSE part 374 * of a true IF), this routine scans the prototype string to decide 375 * where to resume parsing the string. 376 * We must keep track of nested IFs and skip them properly. 377 */ 378 static char * 379 skipcond(p) 380 register char *p; 381 { 382 register int iflevel; 383 384 /* 385 * We came in here after processing a ? or :, 386 * so we start nested one level deep. 387 */ 388 iflevel = 1; 389 390 for (;;) switch (*++p) 391 { 392 case '?': 393 /* 394 * Start of a nested IF. 395 */ 396 iflevel++; 397 break; 398 case ':': 399 /* 400 * Else. 401 * If this matches the IF we came in here with, 402 * then we're done. 403 */ 404 if (iflevel == 1) 405 return (p); 406 break; 407 case '.': 408 /* 409 * Endif. 410 * If this matches the IF we came in here with, 411 * then we're done. 412 */ 413 if (--iflevel == 0) 414 return (p); 415 break; 416 case '\\': 417 /* 418 * Backslash escapes the next character. 419 */ 420 ++p; 421 break; 422 case '\0': 423 /* 424 * Whoops. Hit end of string. 425 * This is a malformed conditional, but just treat it 426 * as if all active conditionals ends here. 427 */ 428 return (p-1); 429 } 430 /*NOTREACHED*/ 431 } 432 433 /* 434 * Decode a char that represents a position on the screen. 435 */ 436 static char * 437 wherechar(p, wp) 438 char *p; 439 int *wp; 440 { 441 switch (*p) 442 { 443 case 'b': case 'd': case 'l': case 'p': case 'P': 444 switch (*++p) 445 { 446 case 't': *wp = TOP; break; 447 case 'm': *wp = MIDDLE; break; 448 case 'b': *wp = BOTTOM; break; 449 case 'B': *wp = BOTTOM_PLUS_ONE; break; 450 case 'j': *wp = adjsline(jump_sline); break; 451 default: *wp = TOP; p--; break; 452 } 453 } 454 return (p); 455 } 456 457 /* 458 * Construct a message based on a prototype string. 459 */ 460 public char * 461 pr_expand(proto, maxwidth) 462 char *proto; 463 int maxwidth; 464 { 465 register char *p; 466 register int c; 467 int where; 468 469 mp = message; 470 471 if (*proto == '\0') 472 return (""); 473 474 for (p = proto; *p != '\0'; p++) 475 { 476 switch (*p) 477 { 478 default: /* Just put the character in the message */ 479 ap_char(*p); 480 break; 481 case '\\': /* Backslash escapes the next character */ 482 p++; 483 ap_char(*p); 484 break; 485 case '?': /* Conditional (IF) */ 486 if ((c = *++p) == '\0') 487 --p; 488 else 489 { 490 where = 0; 491 p = wherechar(p, &where); 492 if (!cond(c, where)) 493 p = skipcond(p); 494 } 495 break; 496 case ':': /* ELSE */ 497 p = skipcond(p); 498 break; 499 case '.': /* ENDIF */ 500 break; 501 case '%': /* Percent escape */ 502 if ((c = *++p) == '\0') 503 --p; 504 else 505 { 506 where = 0; 507 p = wherechar(p, &where); 508 protochar(c, where, 509 #if EDITOR 510 (proto == editproto)); 511 #else 512 0); 513 #endif 514 515 } 516 break; 517 } 518 } 519 520 if (mp == message) 521 return (NULL); 522 if (maxwidth > 0 && mp >= message + maxwidth) 523 { 524 /* 525 * Message is too long. 526 * Return just the final portion of it. 527 */ 528 return (mp - maxwidth); 529 } 530 return (message); 531 } 532 533 /* 534 * Return a message suitable for printing by the "=" command. 535 */ 536 public char * 537 eq_message() 538 { 539 return (pr_expand(eqproto, 0)); 540 } 541 542 /* 543 * Return a prompt. 544 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc. 545 * If we can't come up with an appropriate prompt, return NULL 546 * and the caller will prompt with a colon. 547 */ 548 public char * 549 pr_string() 550 { 551 char *prompt; 552 553 prompt = pr_expand(prproto[pr_type], sc_width-so_s_width-so_e_width-2); 554 new_file = 0; 555 return (prompt); 556 } 557 558 /* 559 * Return a message suitable for printing while waiting in the F command. 560 */ 561 public char * 562 wait_message() 563 { 564 return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2)); 565 } 566