1 /*
2 * Copyright (C) 1984-2025 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 #include "defines.h"
11 #include <stdio.h>
12 #include <string.h>
13 #include <stdlib.h>
14 #include "lesskey.h"
15 #include "cmd.h"
16 #include "xbuf.h"
17
18 #define CONTROL(c) ((c)&037)
19 #define ESC CONTROL('[')
20
21 extern void lesskey_parse_error(char *msg);
22 extern char *homefile(char *filename);
23 extern void *ecalloc(size_t count, size_t size);
24 extern int lstrtoi(char *str, char **end, int radix);
25 extern char version[];
26
27 static int linenum;
28 static int errors;
29 static int less_version = 0;
30 static char *lesskey_file = NULL;
31
32 static constant struct lesskey_cmdname cmdnames[] =
33 {
34 { "back-bracket", A_B_BRACKET },
35 { "back-line", A_B_LINE },
36 { "back-line-force", A_BF_LINE },
37 { "back-newline", A_B_NEWLINE },
38 { "back-screen", A_B_SCREEN },
39 { "back-screen-force", A_BF_SCREEN },
40 { "back-scroll", A_B_SCROLL },
41 { "back-search", A_B_SEARCH },
42 { "back-window", A_B_WINDOW },
43 { "clear-mark", A_CLRMARK },
44 { "clear-search", A_CLR_SEARCH },
45 { "debug", A_DEBUG },
46 { "digit", A_DIGIT },
47 { "display-flag", A_DISP_OPTION },
48 { "display-option", A_DISP_OPTION },
49 { "end", A_GOEND },
50 { "end-scroll", A_RRSHIFT },
51 { "examine", A_EXAMINE },
52 { "filter", A_FILTER },
53 { "first-cmd", A_FIRSTCMD },
54 { "firstcmd", A_FIRSTCMD },
55 { "flush-repaint", A_FREPAINT },
56 { "forw-bracket", A_F_BRACKET },
57 { "forw-forever", A_F_FOREVER },
58 { "forw-line", A_F_LINE },
59 { "forw-line-force", A_FF_LINE },
60 { "forw-newline", A_F_NEWLINE },
61 { "forw-screen", A_F_SCREEN },
62 { "forw-screen-force", A_FF_SCREEN },
63 { "forw-scroll", A_F_SCROLL },
64 { "forw-search", A_F_SEARCH },
65 { "forw-until-hilite", A_F_UNTIL_HILITE },
66 { "forw-window", A_F_WINDOW },
67 { "goto-end", A_GOEND },
68 { "goto-end-buffered", A_GOEND_BUF },
69 { "goto-line", A_GOLINE },
70 { "goto-mark", A_GOMARK },
71 { "help", A_HELP },
72 { "index-file", A_INDEX_FILE },
73 { "invalid", A_UINVALID },
74 { "left-scroll", A_LSHIFT },
75 { "mouse", A_X11MOUSE_IN },
76 { "mouse6", A_X116MOUSE_IN },
77 { "next-file", A_NEXT_FILE },
78 { "next-tag", A_NEXT_TAG },
79 { "no-scroll", A_LLSHIFT },
80 { "noaction", A_NOACTION },
81 { "osc8-forw-search", A_OSC8_F_SEARCH },
82 { "osc8-back-search", A_OSC8_B_SEARCH },
83 { "osc8-open", A_OSC8_OPEN },
84 { "percent", A_PERCENT },
85 { "pipe", A_PIPE },
86 { "prev-file", A_PREV_FILE },
87 { "prev-tag", A_PREV_TAG },
88 { "pshell", A_PSHELL },
89 { "quit", A_QUIT },
90 { "remove-file", A_REMOVE_FILE },
91 { "repaint", A_REPAINT },
92 { "repaint-flush", A_FREPAINT },
93 { "repeat-search", A_AGAIN_SEARCH },
94 { "repeat-search-all", A_T_AGAIN_SEARCH },
95 { "reverse-search", A_REVERSE_SEARCH },
96 { "reverse-search-all", A_T_REVERSE_SEARCH },
97 { "right-scroll", A_RSHIFT },
98 { "set-mark", A_SETMARK },
99 { "set-mark-bottom", A_SETMARKBOT },
100 { "shell", A_SHELL },
101 { "status", A_STAT },
102 { "toggle-flag", A_OPT_TOGGLE },
103 { "toggle-option", A_OPT_TOGGLE },
104 { "undo-hilite", A_UNDO_SEARCH },
105 { "version", A_VERSION },
106 { "visual", A_VISUAL },
107 { NULL, 0 }
108 };
109
110 static constant struct lesskey_cmdname editnames[] =
111 {
112 { "back-complete", EC_B_COMPLETE },
113 { "backspace", EC_BACKSPACE },
114 { "delete", EC_DELETE },
115 { "down", EC_DOWN },
116 { "end", EC_END },
117 { "expand", EC_EXPAND },
118 { "forw-complete", EC_F_COMPLETE },
119 { "home", EC_HOME },
120 { "insert", EC_INSERT },
121 { "invalid", EC_UINVALID },
122 { "kill-line", EC_LINEKILL },
123 { "abort", EC_ABORT },
124 { "left", EC_LEFT },
125 { "literal", EC_LITERAL },
126 { "mouse", EC_X11MOUSE },
127 { "mouse6", EC_X116MOUSE },
128 { "right", EC_RIGHT },
129 { "up", EC_UP },
130 { "word-backspace", EC_W_BACKSPACE },
131 { "word-delete", EC_W_DELETE },
132 { "word-left", EC_W_LEFT },
133 { "word-right", EC_W_RIGHT },
134 { NULL, 0 }
135 };
136
137 /*
138 * Print a parse error message.
139 */
parse_error(constant char * fmt,constant char * arg1)140 static void parse_error(constant char *fmt, constant char *arg1)
141 {
142 char buf[1024];
143 int n = SNPRINTF2(buf, sizeof(buf), "%s: line %d: ", lesskey_file, linenum);
144 if (n >= 0)
145 {
146 size_t len = (size_t) n;
147 if (len < sizeof(buf))
148 SNPRINTF1(buf+len, sizeof(buf)-len, fmt, arg1);
149 }
150 ++errors;
151 lesskey_parse_error(buf);
152 }
153
154 /*
155 * Initialize lesskey_tables.
156 */
init_tables(struct lesskey_tables * tables)157 static void init_tables(struct lesskey_tables *tables)
158 {
159 tables->currtable = &tables->cmdtable;
160
161 tables->cmdtable.names = cmdnames;
162 tables->cmdtable.is_var = 0;
163 xbuf_init(&tables->cmdtable.buf);
164
165 tables->edittable.names = editnames;
166 tables->edittable.is_var = 0;
167 xbuf_init(&tables->edittable.buf);
168
169 tables->vartable.names = NULL;
170 tables->vartable.is_var = 1;
171 xbuf_init(&tables->vartable.buf);
172 }
173
174 #define CHAR_STRING_LEN 8
175
char_string(char * buf,char ch,int lit)176 static constant char * char_string(char *buf, char ch, int lit)
177 {
178 if (lit || (ch >= 0x20 && ch < 0x7f))
179 {
180 buf[0] = ch;
181 buf[1] = '\0';
182 } else
183 {
184 SNPRINTF1(buf, CHAR_STRING_LEN, "\\x%02x", ch);
185 }
186 return buf;
187 }
188
189 /*
190 * Increment char pointer by one up to terminating nul byte.
191 */
increment_pointer(char * p)192 static char * increment_pointer(char *p)
193 {
194 if (*p == '\0')
195 return p;
196 return p+1;
197 }
198
199 /*
200 * Parse one character of a string.
201 */
tstr(char ** pp,int xlate)202 static constant char * tstr(char **pp, int xlate)
203 {
204 char *p;
205 char ch;
206 int i;
207 static char buf[CHAR_STRING_LEN];
208 static char tstr_control_k[] =
209 { SK_SPECIAL_KEY, SK_CONTROL_K, 6, 1, 1, 1, '\0' };
210
211 p = *pp;
212 switch (*p)
213 {
214 case '\\':
215 ++p;
216 switch (*p)
217 {
218 case '0': case '1': case '2': case '3':
219 case '4': case '5': case '6': case '7':
220 /*
221 * Parse an octal number.
222 */
223 ch = 0;
224 i = 0;
225 do
226 ch = (char) (8*ch + (*p - '0'));
227 while (*++p >= '0' && *p <= '7' && ++i < 3);
228 *pp = p;
229 if (xlate && ch == CONTROL('K'))
230 return tstr_control_k;
231 return char_string(buf, ch, 1);
232 case 'b':
233 *pp = p+1;
234 return ("\b");
235 case 'e':
236 *pp = p+1;
237 return char_string(buf, ESC, 1);
238 case 'n':
239 *pp = p+1;
240 return ("\n");
241 case 'r':
242 *pp = p+1;
243 return ("\r");
244 case 't':
245 *pp = p+1;
246 return ("\t");
247 case 'k':
248 if (xlate)
249 {
250 ch = 0;
251 switch (*++p)
252 {
253 case 'b': ch = SK_BACKSPACE; break;
254 case 'B': ch = SK_CTL_BACKSPACE; break;
255 case 'd': ch = SK_DOWN_ARROW; break;
256 case 'D': ch = SK_PAGE_DOWN; break;
257 case 'e': ch = SK_END; break;
258 case 'h': ch = SK_HOME; break;
259 case 'i': ch = SK_INSERT; break;
260 case 'l': ch = SK_LEFT_ARROW; break;
261 case 'L': ch = SK_CTL_LEFT_ARROW; break;
262 case 'r': ch = SK_RIGHT_ARROW; break;
263 case 'R': ch = SK_CTL_RIGHT_ARROW; break;
264 case 't': ch = SK_BACKTAB; break;
265 case 'u': ch = SK_UP_ARROW; break;
266 case 'U': ch = SK_PAGE_UP; break;
267 case 'x': ch = SK_DELETE; break;
268 case 'X': ch = SK_CTL_DELETE; break;
269 case '1': ch = SK_F1; break;
270 case 'p':
271 switch (*++p)
272 {
273 case '1': ch = SK_PAD_DL; break;
274 case '2': ch = SK_PAD_D; break;
275 case '3': ch = SK_PAD_DR; break;
276 case '4': ch = SK_PAD_L; break;
277 case '5': ch = SK_PAD_CENTER; break;
278 case '6': ch = SK_PAD_R; break;
279 case '7': ch = SK_PAD_UL; break;
280 case '8': ch = SK_PAD_U; break;
281 case '9': ch = SK_PAD_UR; break;
282 case '0': ch = SK_PAD_ZERO; break;
283 case '*': ch = SK_PAD_STAR; break;
284 case '/': ch = SK_PAD_SLASH; break;
285 case '-': ch = SK_PAD_DASH; break;
286 case '+': ch = SK_PAD_PLUS; break;
287 case '.': ch = SK_PAD_DOT; break;
288 case ',': ch = SK_PAD_COMMA; break;
289 }
290 break;
291 }
292 if (ch == 0)
293 {
294 parse_error("invalid escape sequence \"\\k%s\"", char_string(buf, *p, 0));
295 *pp = increment_pointer(p);
296 return ("");
297 }
298 *pp = p+1;
299 buf[0] = SK_SPECIAL_KEY;
300 buf[1] = ch;
301 buf[2] = 6;
302 buf[3] = 1;
303 buf[4] = 1;
304 buf[5] = 1;
305 buf[6] = '\0';
306 return (buf);
307 }
308 /* FALLTHRU */
309 default:
310 /*
311 * Backslash followed by any other char
312 * just means that char.
313 */
314 *pp = increment_pointer(p);
315 char_string(buf, *p, 1);
316 if (xlate && buf[0] == CONTROL('K'))
317 return tstr_control_k;
318 return (buf);
319 }
320 case '^':
321 /*
322 * Caret means CONTROL.
323 */
324 *pp = increment_pointer(p+1);
325 char_string(buf, CONTROL(p[1]), 1);
326 if (xlate && buf[0] == CONTROL('K'))
327 return tstr_control_k;
328 return (buf);
329 }
330 *pp = increment_pointer(p);
331 char_string(buf, *p, 1);
332 if (xlate && buf[0] == CONTROL('K'))
333 return tstr_control_k;
334 return (buf);
335 }
336
issp(char ch)337 static int issp(char ch)
338 {
339 return (ch == ' ' || ch == '\t');
340 }
341
342 /*
343 * Skip leading spaces in a string.
344 */
skipsp(char * s)345 static char * skipsp(char *s)
346 {
347 while (issp(*s))
348 s++;
349 return (s);
350 }
351
352 /*
353 * Skip non-space characters in a string.
354 */
skipnsp(char * s)355 static char * skipnsp(char *s)
356 {
357 while (*s != '\0' && !issp(*s))
358 s++;
359 return (s);
360 }
361
362 /*
363 * Clean up an input line:
364 * strip off the trailing newline & any trailing # comment.
365 */
clean_line(char * s)366 static char * clean_line(char *s)
367 {
368 int i;
369
370 s = skipsp(s);
371 for (i = 0; s[i] != '\0' && s[i] != '\n' && s[i] != '\r'; i++)
372 if (s[i] == '#' && (i == 0 || s[i-1] != '\\'))
373 break;
374 s[i] = '\0';
375 return (s);
376 }
377
378 /*
379 * Add a byte to the output command table.
380 */
add_cmd_char(unsigned char c,struct lesskey_tables * tables)381 static void add_cmd_char(unsigned char c, struct lesskey_tables *tables)
382 {
383 xbuf_add_byte(&tables->currtable->buf, c);
384 }
385
erase_cmd_char(struct lesskey_tables * tables)386 static void erase_cmd_char(struct lesskey_tables *tables)
387 {
388 xbuf_pop(&tables->currtable->buf);
389 }
390
391 /*
392 * Add a string to the output command table.
393 */
add_cmd_str(constant char * s,struct lesskey_tables * tables)394 static void add_cmd_str(constant char *s, struct lesskey_tables *tables)
395 {
396 for ( ; *s != '\0'; s++)
397 add_cmd_char((unsigned char) *s, tables);
398 }
399
400 /*
401 * Does a given version number match the running version?
402 * Operator compares the running version to the given version.
403 */
match_version(char op,int ver)404 static int match_version(char op, int ver)
405 {
406 switch (op)
407 {
408 case '>': return less_version > ver;
409 case '<': return less_version < ver;
410 case '+': return less_version >= ver;
411 case '-': return less_version <= ver;
412 case '=': return less_version == ver;
413 case '!': return less_version != ver;
414 default: return 0; /* cannot happen */
415 }
416 }
417
418 /*
419 * Handle a #version line.
420 * If the version matches, return the part of the line that should be executed.
421 * Otherwise, return NULL.
422 */
version_line(char * s)423 static char * version_line(char *s)
424 {
425 char op;
426 int ver;
427 char *e;
428 char buf[CHAR_STRING_LEN];
429
430 s += strlen("#version");
431 s = skipsp(s);
432 op = *s++;
433 /* Simplify 2-char op to one char. */
434 switch (op)
435 {
436 case '<': if (*s == '=') { s++; op = '-'; } break;
437 case '>': if (*s == '=') { s++; op = '+'; } break;
438 case '=': if (*s == '=') { s++; } break;
439 case '!': if (*s == '=') { s++; } break;
440 default:
441 parse_error("invalid operator '%s' in #version line", char_string(buf, op, 0));
442 return (NULL);
443 }
444 s = skipsp(s);
445 ver = lstrtoi(s, &e, 10);
446 if (e == s)
447 {
448 parse_error("non-numeric version number in #version line", "");
449 return (NULL);
450 }
451 if (!match_version(op, ver))
452 return (NULL);
453 return (e);
454 }
455
456 /*
457 * See if we have a special "control" line.
458 */
control_line(char * s,struct lesskey_tables * tables)459 static char * control_line(char *s, struct lesskey_tables *tables)
460 {
461 #define PREFIX(str,pat) (strncmp(str,pat,strlen(pat)) == 0)
462
463 if (PREFIX(s, "#line-edit"))
464 {
465 tables->currtable = &tables->edittable;
466 return (NULL);
467 }
468 if (PREFIX(s, "#command"))
469 {
470 tables->currtable = &tables->cmdtable;
471 return (NULL);
472 }
473 if (PREFIX(s, "#env"))
474 {
475 tables->currtable = &tables->vartable;
476 return (NULL);
477 }
478 if (PREFIX(s, "#stop"))
479 {
480 add_cmd_char('\0', tables);
481 add_cmd_char(A_END_LIST, tables);
482 return (NULL);
483 }
484 if (PREFIX(s, "#version"))
485 {
486 return (version_line(s));
487 }
488 return (s);
489 }
490
491 /*
492 * Find an action, given the name of the action.
493 */
findaction(char * actname,struct lesskey_tables * tables)494 static int findaction(char *actname, struct lesskey_tables *tables)
495 {
496 int i;
497
498 for (i = 0; tables->currtable->names[i].cn_name != NULL; i++)
499 if (strcmp(tables->currtable->names[i].cn_name, actname) == 0)
500 return (tables->currtable->names[i].cn_action);
501 parse_error("unknown action: \"%s\"", actname);
502 return (A_INVALID);
503 }
504
505 /*
506 * Parse a line describing one key binding, of the form
507 * KEY ACTION [EXTRA]
508 * where KEY is the user key sequence, ACTION is the
509 * resulting less action, and EXTRA is an "extra" user
510 * key sequence injected after the action.
511 */
parse_cmdline(char * p,struct lesskey_tables * tables)512 static void parse_cmdline(char *p, struct lesskey_tables *tables)
513 {
514 char *actname;
515 int action;
516 constant char *s;
517 char c;
518
519 /*
520 * Parse the command string and store it in the current table.
521 */
522 do
523 {
524 s = tstr(&p, 1);
525 add_cmd_str(s, tables);
526 } while (*p != '\0' && !issp(*p));
527 /*
528 * Terminate the command string with a null byte.
529 */
530 add_cmd_char('\0', tables);
531
532 /*
533 * Skip white space between the command string
534 * and the action name.
535 * Terminate the action name with a null byte.
536 */
537 p = skipsp(p);
538 if (*p == '\0')
539 {
540 parse_error("missing action", "");
541 return;
542 }
543 actname = p;
544 p = skipnsp(p);
545 c = *p;
546 *p = '\0';
547
548 /*
549 * Parse the action name and store it in the current table.
550 */
551 action = findaction(actname, tables);
552
553 /*
554 * See if an extra string follows the action name.
555 */
556 *p = c;
557 p = skipsp(p);
558 if (*p == '\0')
559 {
560 add_cmd_char((unsigned char) action, tables);
561 } else
562 {
563 /*
564 * OR the special value A_EXTRA into the action byte.
565 * Put the extra string after the action byte.
566 */
567 add_cmd_char((unsigned char) (action | A_EXTRA), tables);
568 while (*p != '\0')
569 add_cmd_str(tstr(&p, 0), tables);
570 add_cmd_char('\0', tables);
571 }
572 }
573
574 /*
575 * Parse a variable definition line, of the form
576 * NAME = VALUE
577 */
parse_varline(char * line,struct lesskey_tables * tables)578 static void parse_varline(char *line, struct lesskey_tables *tables)
579 {
580 constant char *s;
581 char *p = line;
582 char *eq;
583
584 eq = strchr(line, '=');
585 if (eq != NULL && eq > line && eq[-1] == '+')
586 {
587 /*
588 * Rather ugly way of handling a += line.
589 * {{ Note that we ignore the variable name and
590 * just append to the previously defined variable. }}
591 */
592 erase_cmd_char(tables); /* backspace over the final null */
593 p = eq+1;
594 } else
595 {
596 do
597 {
598 s = tstr(&p, 0);
599 add_cmd_str(s, tables);
600 } while (*p != '\0' && !issp(*p) && *p != '=');
601 /*
602 * Terminate the variable name with a null byte.
603 */
604 add_cmd_char('\0', tables);
605 p = skipsp(p);
606 if (*p++ != '=')
607 {
608 parse_error("missing = in variable definition", "");
609 return;
610 }
611 add_cmd_char(EV_OK|A_EXTRA, tables);
612 }
613 p = skipsp(p);
614 while (*p != '\0')
615 {
616 s = tstr(&p, 0);
617 add_cmd_str(s, tables);
618 }
619 add_cmd_char('\0', tables);
620 }
621
622 /*
623 * Parse a line from the lesskey file.
624 */
parse_line(char * line,struct lesskey_tables * tables)625 static void parse_line(char *line, struct lesskey_tables *tables)
626 {
627 char *p;
628
629 /*
630 * See if it is a control line.
631 */
632 p = control_line(line, tables);
633 if (p == NULL)
634 return;
635 /*
636 * Skip leading white space.
637 * Replace the final newline with a null byte.
638 * Ignore blank lines and comments.
639 */
640 p = clean_line(p);
641 if (*p == '\0')
642 return;
643
644 if (tables->currtable->is_var)
645 parse_varline(p, tables);
646 else
647 parse_cmdline(p, tables);
648 }
649
650 /*
651 * Parse a lesskey source file and store result in tables.
652 */
parse_lesskey(constant char * infile,struct lesskey_tables * tables)653 int parse_lesskey(constant char *infile, struct lesskey_tables *tables)
654 {
655 FILE *desc;
656 char line[1024];
657
658 lesskey_file = (infile != NULL) ? strdup(infile) : homefile(DEF_LESSKEYINFILE);
659 if (lesskey_file == NULL)
660 return (-1);
661
662 init_tables(tables);
663 errors = 0;
664 linenum = 0;
665 if (less_version == 0)
666 less_version = lstrtoi(version, NULL, 10);
667
668 /*
669 * Open the input file.
670 */
671 if (strcmp(lesskey_file, "-") == 0)
672 desc = stdin;
673 else if ((desc = fopen(lesskey_file, "r")) == NULL)
674 {
675 /* parse_error("cannot open lesskey file %s", lesskey_file); */
676 errors = -1;
677 }
678
679 /*
680 * Read and parse the input file, one line at a time.
681 */
682 if (desc != NULL)
683 {
684 while (fgets(line, sizeof(line), desc) != NULL)
685 {
686 ++linenum;
687 parse_line(line, tables);
688 }
689 if (desc != stdin)
690 fclose(desc);
691 }
692 free(lesskey_file);
693 lesskey_file = NULL;
694 return (errors);
695 }
696
697 /*
698 * Parse a lesskey source content and store result in tables.
699 */
parse_lesskey_content(constant char * content,struct lesskey_tables * tables)700 int parse_lesskey_content(constant char *content, struct lesskey_tables *tables)
701 {
702 size_t cx = 0;
703
704 lesskey_file = "lesskey-content";
705 init_tables(tables);
706 errors = 0;
707 linenum = 0;
708 if (less_version == 0)
709 less_version = lstrtoi(version, NULL, 10);
710
711 while (content[cx] != '\0')
712 {
713 /* Extract a line from the content buffer and parse it. */
714 char line[1024];
715 size_t lx = 0;
716 while (content[cx] != '\0' && content[cx] != '\n' && content[cx] != ';')
717 {
718 if (lx >= sizeof(line)-1) break;
719 if (content[cx] == '\\' && content[cx+1] == ';')
720 ++cx; /* escaped semicolon: skip the backslash */
721 line[lx++] = content[cx++];
722 }
723 line[lx] = '\0';
724 ++linenum;
725 parse_line(line, tables);
726 if (content[cx] != '\0') ++cx; /* skip newline or semicolon */
727 }
728 lesskey_file = NULL;
729 return (errors);
730 }
731