1 /*
2 * Copyright (C) 1984-2026 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-bell-hilite", A_F_FOREVER_BELL },
57 { "forw-bracket", A_F_BRACKET },
58 { "forw-forever", A_F_FOREVER },
59 { "forw-line", A_F_LINE },
60 { "forw-line-force", A_FF_LINE },
61 { "forw-newline", A_F_NEWLINE },
62 { "forw-screen", A_F_SCREEN },
63 { "forw-screen-force", A_FF_SCREEN },
64 { "forw-scroll", A_F_SCROLL },
65 { "forw-search", A_F_SEARCH },
66 { "forw-until-hilite", A_F_UNTIL_HILITE },
67 { "forw-window", A_F_WINDOW },
68 { "goto-end", A_GOEND },
69 { "goto-end-buffered", A_GOEND_BUF },
70 { "goto-line", A_GOLINE },
71 { "goto-mark", A_GOMARK },
72 { "goto-pos", A_GOPOS },
73 { "help", A_HELP },
74 { "index-file", A_INDEX_FILE },
75 { "invalid", A_UINVALID },
76 { "left-scroll", A_LSHIFT },
77 { "mouse", A_X11MOUSE_IN },
78 { "mouse6", A_X116MOUSE_IN },
79 { "next-file", A_NEXT_FILE },
80 { "next-tag", A_NEXT_TAG },
81 { "no-scroll", A_LLSHIFT },
82 { "noaction", A_NOACTION },
83 { "osc8-forw-search", A_OSC8_F_SEARCH },
84 { "osc8-back-search", A_OSC8_B_SEARCH },
85 { "osc8-jump", A_OSC8_JUMP },
86 { "osc8-open", A_OSC8_OPEN },
87 { "percent", A_PERCENT },
88 { "pipe", A_PIPE },
89 { "prev-file", A_PREV_FILE },
90 { "prev-tag", A_PREV_TAG },
91 { "pshell", A_PSHELL },
92 { "quit", A_QUIT },
93 { "remove-file", A_REMOVE_FILE },
94 { "repaint", A_REPAINT },
95 { "repaint-flush", A_FREPAINT },
96 { "repeat-search", A_AGAIN_SEARCH },
97 { "repeat-search-all", A_T_AGAIN_SEARCH },
98 { "reverse-search", A_REVERSE_SEARCH },
99 { "reverse-search-all", A_T_REVERSE_SEARCH },
100 { "right-scroll", A_RSHIFT },
101 { "set-mark", A_SETMARK },
102 { "set-mark-bottom", A_SETMARKBOT },
103 { "shell", A_SHELL },
104 { "status", A_STAT },
105 { "toggle-flag", A_OPT_TOGGLE },
106 { "toggle-option", A_OPT_TOGGLE },
107 { "undo-hilite", A_UNDO_SEARCH },
108 { "version", A_VERSION },
109 { "visual", A_VISUAL },
110 { NULL, 0 }
111 };
112
113 static constant struct lesskey_cmdname editnames[] =
114 {
115 { "back-complete", EC_B_COMPLETE },
116 { "backspace", EC_BACKSPACE },
117 { "delete", EC_DELETE },
118 { "down", EC_DOWN },
119 { "end", EC_END },
120 { "expand", EC_EXPAND },
121 { "forw-complete", EC_F_COMPLETE },
122 { "home", EC_HOME },
123 { "insert", EC_INSERT },
124 { "invalid", EC_UINVALID },
125 { "kill-line", EC_LINEKILL },
126 { "abort", EC_ABORT },
127 { "left", EC_LEFT },
128 { "literal", EC_LITERAL },
129 { "mouse", EC_X11MOUSE },
130 { "mouse6", EC_X116MOUSE },
131 { "noaction", A_NOACTION },
132 { "right", EC_RIGHT },
133 { "up", EC_UP },
134 { "word-backspace", EC_W_BACKSPACE },
135 { "word-delete", EC_W_DELETE },
136 { "word-left", EC_W_LEFT },
137 { "word-right", EC_W_RIGHT },
138 { NULL, 0 }
139 };
140
141 /*
142 * Print a parse error message.
143 */
parse_error(constant char * fmt,constant char * arg1)144 static void parse_error(constant char *fmt, constant char *arg1)
145 {
146 char buf[1024];
147 int n = SNPRINTF2(buf, sizeof(buf), "%s: line %d: ", lesskey_file, linenum);
148 if (n >= 0)
149 {
150 size_t len = (size_t) n;
151 if (len < sizeof(buf))
152 SNPRINTF1(buf+len, sizeof(buf)-len, fmt, arg1);
153 }
154 ++errors;
155 lesskey_parse_error(buf);
156 }
157
158 /*
159 * Initialize lesskey_tables.
160 */
init_tables(struct lesskey_tables * tables)161 static void init_tables(struct lesskey_tables *tables)
162 {
163 tables->currtable = &tables->cmdtable;
164
165 tables->cmdtable.names = cmdnames;
166 tables->cmdtable.is_var = 0;
167 xbuf_init(&tables->cmdtable.buf);
168
169 tables->edittable.names = editnames;
170 tables->edittable.is_var = 0;
171 xbuf_init(&tables->edittable.buf);
172
173 tables->vartable.names = NULL;
174 tables->vartable.is_var = 1;
175 xbuf_init(&tables->vartable.buf);
176 }
177
178 #define CHAR_STRING_LEN 8
179
char_string(char * buf,char ch,int lit)180 static constant char * char_string(char *buf, char ch, int lit)
181 {
182 if (lit || (ch >= 0x20 && ch < 0x7f))
183 {
184 buf[0] = ch;
185 buf[1] = '\0';
186 } else
187 {
188 SNPRINTF1(buf, CHAR_STRING_LEN, "\\x%02x", ch);
189 }
190 return buf;
191 }
192
193 /*
194 * Increment char pointer by one up to terminating nul byte.
195 */
increment_pointer(char * p)196 static char * increment_pointer(char *p)
197 {
198 if (*p == '\0')
199 return p;
200 return p+1;
201 }
202
203 /*
204 * Parse one character of a string.
205 */
tstr(char ** pp,int xlate)206 static constant char * tstr(char **pp, int xlate)
207 {
208 char *p;
209 char ch;
210 int i;
211 static char buf[CHAR_STRING_LEN];
212 static char tstr_control_k[] =
213 { SK_SPECIAL_KEY, SK_CONTROL_K, 6, 1, 1, 1, '\0' };
214
215 p = *pp;
216 switch (*p)
217 {
218 case '\\':
219 ++p;
220 switch (*p)
221 {
222 case '0': case '1': case '2': case '3':
223 case '4': case '5': case '6': case '7':
224 /*
225 * Parse an octal number.
226 */
227 ch = 0;
228 i = 0;
229 do
230 ch = (char) (8*ch + (*p - '0'));
231 while (*++p >= '0' && *p <= '7' && ++i < 3);
232 *pp = p;
233 if (xlate && ch == CONTROL('K'))
234 return tstr_control_k;
235 return char_string(buf, ch, 1);
236 case 'b':
237 *pp = p+1;
238 return ("\b");
239 case 'e':
240 *pp = p+1;
241 return char_string(buf, ESC, 1);
242 case 'n':
243 *pp = p+1;
244 return ("\n");
245 case 'r':
246 *pp = p+1;
247 return ("\r");
248 case 't':
249 *pp = p+1;
250 return ("\t");
251 case 'k':
252 if (xlate)
253 {
254 ch = 0;
255 switch (*++p)
256 {
257 case 'b': ch = SK_BACKSPACE; break;
258 case 'B': ch = SK_CTL_BACKSPACE; break;
259 case 'd': ch = SK_DOWN_ARROW; break;
260 case 'D': ch = SK_PAGE_DOWN; break;
261 case 'e': ch = SK_END; break;
262 case 'E': ch = SK_CTL_END; break;
263 case 'F': ch = SK_SHIFT_END; break;
264 case 'h': ch = SK_HOME; break;
265 case 'H': ch = SK_CTL_HOME; break;
266 case 'I': ch = SK_SHIFT_HOME; break;
267 case 'i': ch = SK_INSERT; break;
268 case 'l': ch = SK_LEFT_ARROW; break;
269 case 'L': ch = SK_CTL_LEFT_ARROW; break;
270 case 'M': ch = SK_SHIFT_LEFT_ARROW; break;
271 case 'r': ch = SK_RIGHT_ARROW; break;
272 case 'R': ch = SK_CTL_RIGHT_ARROW; break;
273 case 'S': ch = SK_SHIFT_RIGHT_ARROW; break;
274 case 't': ch = SK_BACKTAB; break;
275 case 'u': ch = SK_UP_ARROW; break;
276 case 'U': ch = SK_PAGE_UP; break;
277 case 'x': ch = SK_DELETE; break;
278 case 'X': ch = SK_CTL_DELETE; break;
279 case '1': ch = SK_F1; break;
280 case 'p':
281 switch (*++p)
282 {
283 case '1': ch = SK_PAD_DL; break;
284 case '2': ch = SK_PAD_D; break;
285 case '3': ch = SK_PAD_DR; break;
286 case '4': ch = SK_PAD_L; break;
287 case '5': ch = SK_PAD_CENTER; break;
288 case '6': ch = SK_PAD_R; break;
289 case '7': ch = SK_PAD_UL; break;
290 case '8': ch = SK_PAD_U; break;
291 case '9': ch = SK_PAD_UR; break;
292 case '0': ch = SK_PAD_ZERO; break;
293 case '*': ch = SK_PAD_STAR; break;
294 case '/': ch = SK_PAD_SLASH; break;
295 case '-': ch = SK_PAD_DASH; break;
296 case '+': ch = SK_PAD_PLUS; break;
297 case '.': ch = SK_PAD_DOT; break;
298 case ',': ch = SK_PAD_COMMA; break;
299 case 'e': ch = SK_PAD_ENTER; break;
300 }
301 break;
302 }
303 if (ch == 0)
304 {
305 parse_error("invalid escape sequence \"\\k%s\"", char_string(buf, *p, 0));
306 *pp = increment_pointer(p);
307 return ("");
308 }
309 *pp = p+1;
310 buf[0] = SK_SPECIAL_KEY;
311 buf[1] = ch;
312 buf[2] = 6;
313 buf[3] = 1;
314 buf[4] = 1;
315 buf[5] = 1;
316 buf[6] = '\0';
317 return (buf);
318 }
319 /* FALLTHRU */
320 default:
321 /*
322 * Backslash followed by any other char
323 * just means that char.
324 */
325 *pp = increment_pointer(p);
326 char_string(buf, *p, 1);
327 if (xlate && buf[0] == CONTROL('K'))
328 return tstr_control_k;
329 return (buf);
330 }
331 case '^':
332 /*
333 * Caret means CONTROL.
334 */
335 *pp = increment_pointer(p+1);
336 char_string(buf, CONTROL(p[1]), 1);
337 if (xlate && buf[0] == CONTROL('K'))
338 return tstr_control_k;
339 return (buf);
340 }
341 *pp = increment_pointer(p);
342 char_string(buf, *p, 1);
343 if (xlate && buf[0] == CONTROL('K'))
344 return tstr_control_k;
345 return (buf);
346 }
347
issp(char ch)348 static int issp(char ch)
349 {
350 return (ch == ' ' || ch == '\t');
351 }
352
353 /*
354 * Skip leading spaces in a string.
355 */
skipsp(char * s)356 static char * skipsp(char *s)
357 {
358 while (issp(*s))
359 s++;
360 return (s);
361 }
362
363 /*
364 * Skip non-space characters in a string.
365 */
skipnsp(char * s)366 static char * skipnsp(char *s)
367 {
368 while (*s != '\0' && !issp(*s))
369 s++;
370 return (s);
371 }
372
373 /*
374 * Clean up an input line:
375 * strip off the trailing newline & any trailing # comment.
376 */
clean_line(char * s)377 static char * clean_line(char *s)
378 {
379 int i;
380
381 s = skipsp(s);
382 for (i = 0; s[i] != '\0' && s[i] != '\n' && s[i] != '\r'; i++)
383 if (s[i] == '#' && (i == 0 || s[i-1] != '\\'))
384 break;
385 s[i] = '\0';
386 return (s);
387 }
388
389 /*
390 * Add a byte to the output command table.
391 */
add_cmd_char(unsigned char c,struct lesskey_tables * tables)392 static void add_cmd_char(unsigned char c, struct lesskey_tables *tables)
393 {
394 xbuf_add_byte(&tables->currtable->buf, c);
395 }
396
erase_cmd_char(struct lesskey_tables * tables)397 static void erase_cmd_char(struct lesskey_tables *tables)
398 {
399 xbuf_pop(&tables->currtable->buf);
400 }
401
402 /*
403 * Add a string to the output command table.
404 */
add_cmd_str(constant char * s,struct lesskey_tables * tables)405 static void add_cmd_str(constant char *s, struct lesskey_tables *tables)
406 {
407 for ( ; *s != '\0'; s++)
408 add_cmd_char((unsigned char) *s, tables);
409 }
410
411 /*
412 * Does a given version number match the running version?
413 * Operator compares the running version to the given version.
414 */
match_version(char op,int ver)415 static int match_version(char op, int ver)
416 {
417 switch (op)
418 {
419 case '>': return less_version > ver;
420 case '<': return less_version < ver;
421 case '+': return less_version >= ver;
422 case '-': return less_version <= ver;
423 case '=': return less_version == ver;
424 case '!': return less_version != ver;
425 default: return 0; /* cannot happen */
426 }
427 }
428
429 /*
430 * Handle a #version line.
431 * If the version matches, return the part of the line that should be executed.
432 * Otherwise, return NULL.
433 */
version_line(char * s)434 static char * version_line(char *s)
435 {
436 char op;
437 int ver;
438 char *e;
439 char buf[CHAR_STRING_LEN];
440
441 s += strlen("#version");
442 s = skipsp(s);
443 op = *s++;
444 /* Simplify 2-char op to one char. */
445 switch (op)
446 {
447 case '<': if (*s == '=') { s++; op = '-'; } break;
448 case '>': if (*s == '=') { s++; op = '+'; } break;
449 case '=': if (*s == '=') { s++; } break;
450 case '!': if (*s == '=') { s++; } break;
451 default:
452 parse_error("invalid operator '%s' in #version line", char_string(buf, op, 0));
453 return (NULL);
454 }
455 s = skipsp(s);
456 ver = lstrtoi(s, &e, 10);
457 if (e == s)
458 {
459 parse_error("non-numeric version number in #version line", "");
460 return (NULL);
461 }
462 if (!match_version(op, ver))
463 return (NULL);
464 return (e);
465 }
466
467 /*
468 * See if we have a special "control" line.
469 */
control_line(char * s,struct lesskey_tables * tables)470 static char * control_line(char *s, struct lesskey_tables *tables)
471 {
472 #define PREFIX(str,pat) (strncmp(str,pat,strlen(pat)) == 0)
473
474 if (PREFIX(s, "#line-edit"))
475 {
476 tables->currtable = &tables->edittable;
477 return (NULL);
478 }
479 if (PREFIX(s, "#command"))
480 {
481 tables->currtable = &tables->cmdtable;
482 return (NULL);
483 }
484 if (PREFIX(s, "#env"))
485 {
486 tables->currtable = &tables->vartable;
487 return (NULL);
488 }
489 if (PREFIX(s, "#stop"))
490 {
491 add_cmd_char('\0', tables);
492 add_cmd_char(A_END_LIST, tables);
493 return (NULL);
494 }
495 if (PREFIX(s, "#version"))
496 {
497 return (version_line(s));
498 }
499 return (s);
500 }
501
502 /*
503 * Find an action, given the name of the action.
504 */
findaction(char * actname,struct lesskey_tables * tables)505 static int findaction(char *actname, struct lesskey_tables *tables)
506 {
507 int i;
508
509 for (i = 0; tables->currtable->names[i].cn_name != NULL; i++)
510 if (strcmp(tables->currtable->names[i].cn_name, actname) == 0)
511 return (tables->currtable->names[i].cn_action);
512 parse_error("unknown action: \"%s\"", actname);
513 return (A_INVALID);
514 }
515
516 /*
517 * Parse a line describing one key binding, of the form
518 * KEY ACTION [EXTRA]
519 * where KEY is the user key sequence, ACTION is the
520 * resulting less action, and EXTRA is an "extra" user
521 * key sequence injected after the action.
522 */
parse_cmdline(char * p,struct lesskey_tables * tables)523 static void parse_cmdline(char *p, struct lesskey_tables *tables)
524 {
525 char *actname;
526 int action;
527 constant char *s;
528 char c;
529
530 /*
531 * Parse the command string and store it in the current table.
532 */
533 do
534 {
535 s = tstr(&p, 1);
536 add_cmd_str(s, tables);
537 } while (*p != '\0' && !issp(*p));
538 /*
539 * Terminate the command string with a null byte.
540 */
541 add_cmd_char('\0', tables);
542
543 /*
544 * Skip white space between the command string
545 * and the action name.
546 * Terminate the action name with a null byte.
547 */
548 p = skipsp(p);
549 if (*p == '\0')
550 {
551 parse_error("missing action", "");
552 return;
553 }
554 actname = p;
555 p = skipnsp(p);
556 c = *p;
557 *p = '\0';
558
559 /*
560 * Parse the action name and store it in the current table.
561 */
562 action = findaction(actname, tables);
563
564 /*
565 * See if an extra string follows the action name.
566 */
567 *p = c;
568 p = skipsp(p);
569 if (*p == '\0')
570 {
571 add_cmd_char((unsigned char) action, tables);
572 } else
573 {
574 /*
575 * OR the special value A_EXTRA into the action byte.
576 * Put the extra string after the action byte.
577 */
578 add_cmd_char((unsigned char) (action | A_EXTRA), tables);
579 while (*p != '\0')
580 add_cmd_str(tstr(&p, 0), tables);
581 add_cmd_char('\0', tables);
582 }
583 }
584
585 /*
586 * Parse a variable definition line, of the form
587 * NAME = VALUE
588 */
parse_varline(char * line,struct lesskey_tables * tables)589 static void parse_varline(char *line, struct lesskey_tables *tables)
590 {
591 constant char *s;
592 char *p = line;
593 char *eq;
594
595 eq = strchr(line, '=');
596 if (eq != NULL && eq > line && eq[-1] == '+')
597 {
598 /*
599 * Rather ugly way of handling a += line.
600 * {{ Note that we ignore the variable name and
601 * just append to the previously defined variable. }}
602 */
603 erase_cmd_char(tables); /* backspace over the final null */
604 p = eq+1;
605 } else
606 {
607 do
608 {
609 s = tstr(&p, 0);
610 add_cmd_str(s, tables);
611 } while (*p != '\0' && !issp(*p) && *p != '=');
612 /*
613 * Terminate the variable name with a null byte.
614 */
615 add_cmd_char('\0', tables);
616 p = skipsp(p);
617 if (*p++ != '=')
618 {
619 parse_error("missing = in variable definition", "");
620 return;
621 }
622 add_cmd_char(EV_OK|A_EXTRA, tables);
623 }
624 p = skipsp(p);
625 while (*p != '\0')
626 {
627 s = tstr(&p, 0);
628 add_cmd_str(s, tables);
629 }
630 add_cmd_char('\0', tables);
631 }
632
633 /*
634 * Parse a line from the lesskey file.
635 */
parse_line(char * line,struct lesskey_tables * tables)636 static void parse_line(char *line, struct lesskey_tables *tables)
637 {
638 char *p;
639
640 /*
641 * See if it is a control line.
642 */
643 p = control_line(line, tables);
644 if (p == NULL)
645 return;
646 /*
647 * Skip leading white space.
648 * Replace the final newline with a null byte.
649 * Ignore blank lines and comments.
650 */
651 p = clean_line(p);
652 if (*p == '\0')
653 return;
654
655 if (tables->currtable->is_var)
656 parse_varline(p, tables);
657 else
658 parse_cmdline(p, tables);
659 }
660
661 /*
662 * Parse a lesskey source file and store result in tables.
663 */
parse_lesskey(constant char * infile,struct lesskey_tables * tables)664 int parse_lesskey(constant char *infile, struct lesskey_tables *tables)
665 {
666 FILE *desc;
667 char line[1024];
668
669 lesskey_file = (infile != NULL) ? strdup(infile) : homefile(DEF_LESSKEYINFILE);
670 if (lesskey_file == NULL)
671 return (-1);
672
673 init_tables(tables);
674 errors = 0;
675 linenum = 0;
676 if (less_version == 0)
677 less_version = lstrtoi(version, NULL, 10);
678
679 /*
680 * Open the input file.
681 */
682 if (strcmp(lesskey_file, "-") == 0)
683 desc = stdin;
684 else if ((desc = fopen(lesskey_file, "r")) == NULL)
685 {
686 /* parse_error("cannot open lesskey file %s", lesskey_file); */
687 errors = -1;
688 }
689
690 /*
691 * Read and parse the input file, one line at a time.
692 */
693 if (desc != NULL)
694 {
695 while (fgets(line, sizeof(line), desc) != NULL)
696 {
697 ++linenum;
698 parse_line(line, tables);
699 }
700 if (desc != stdin)
701 fclose(desc);
702 }
703 free(lesskey_file);
704 lesskey_file = NULL;
705 return (errors);
706 }
707
708 /*
709 * Parse a lesskey source content and store result in tables.
710 */
parse_lesskey_content(constant char * content,struct lesskey_tables * tables)711 int parse_lesskey_content(constant char *content, struct lesskey_tables *tables)
712 {
713 size_t cx = 0;
714
715 lesskey_file = "lesskey-content";
716 init_tables(tables);
717 errors = 0;
718 linenum = 0;
719 if (less_version == 0)
720 less_version = lstrtoi(version, NULL, 10);
721
722 while (content[cx] != '\0')
723 {
724 /* Extract a line from the content buffer and parse it. */
725 char line[1024];
726 size_t lx = 0;
727 while (content[cx] != '\0' && content[cx] != '\n' && content[cx] != ';')
728 {
729 if (lx >= sizeof(line)-1) break;
730 if (content[cx] == '\\' && content[cx+1] == ';')
731 ++cx; /* escaped semicolon: skip the backslash */
732 line[lx++] = content[cx++];
733 }
734 line[lx] = '\0';
735 ++linenum;
736 parse_line(line, tables);
737 if (content[cx] != '\0') ++cx; /* skip newline or semicolon */
738 }
739 lesskey_file = NULL;
740 return (errors);
741 }
742