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
11 /*
12 * Entry point, initialization, miscellaneous routines.
13 */
14
15 #include "less.h"
16 #if MSDOS_COMPILER==WIN32C
17 #define WIN32_LEAN_AND_MEAN
18 #include <windows.h>
19
20 #if defined(__MINGW32__) || defined(_MSC_VER)
21 #include <locale.h>
22 #include <shellapi.h>
23 #endif
24
25 public unsigned less_acp = CP_ACP;
26 #endif
27
28 #include "option.h"
29
30 public char * every_first_cmd = NULL;
31 public lbool new_file;
32 public int is_tty;
33 public IFILE curr_ifile = NULL_IFILE;
34 public IFILE old_ifile = NULL_IFILE;
35 public struct scrpos initial_scrpos;
36 public POSITION start_attnpos = NULL_POSITION;
37 public POSITION end_attnpos = NULL_POSITION;
38 public int wscroll;
39 public constant char *progname;
40 public lbool quitting = FALSE;
41 public int dohelp;
42 public char * init_header = NULL;
43 public char * no_config = NULL;
44 static int secure_allow_features;
45
46 #if LOGFILE
47 public int logfile = -1;
48 public lbool force_logfile = FALSE;
49 public char * namelogfile = NULL;
50 #endif
51
52 #if EDITOR
53 public constant char * editor;
54 public constant char * editproto;
55 #endif
56
57 #if TAGS
58 extern char * tags;
59 extern char * tagoption;
60 extern int jump_sline;
61 #endif
62
63 #if HAVE_TIME
64 public time_type less_start_time;
65 #endif
66
67 #ifdef WIN32
68 static wchar_t consoleTitle[256];
69 #endif
70
71 public int one_screen;
72 extern int less_is_more;
73 extern lbool missing_cap;
74 extern int know_dumb;
75 extern int quit_if_one_screen;
76 extern int no_init;
77 extern int errmsgs;
78 extern int redraw_on_quit;
79 extern int term_addrs;
80 extern lbool first_time;
81 extern lbool term_init_ever;
82
83 #if MSDOS_COMPILER==WIN32C && (defined(__MINGW32__) || defined(_MSC_VER))
84 /* malloc'ed 0-terminated utf8 of 0-terminated wide ws, or null on errors */
utf8_from_wide(constant wchar_t * ws)85 static char *utf8_from_wide(constant wchar_t *ws)
86 {
87 char *u8 = NULL;
88 int n = WideCharToMultiByte(CP_UTF8, 0, ws, -1, NULL, 0, NULL, NULL);
89 if (n > 0)
90 {
91 u8 = ecalloc(n, sizeof(char));
92 WideCharToMultiByte(CP_UTF8, 0, ws, -1, u8, n, NULL, NULL);
93 }
94 return u8;
95 }
96
97 /*
98 * similar to using UTF8 manifest to make the ANSI APIs UTF8, but dynamically
99 * with setlocale. unlike the manifest, argv and environ are already ACP, so
100 * make them UTF8. Additionally, this affects only the libc/crt API, and so
101 * e.g. fopen filename becomes UTF-8, but CreateFileA filename remains CP_ACP.
102 * CP_ACP remains the original codepage - use the dynamic less_acp instead.
103 * effective on win 10 1803 or later when compiled with ucrt, else no-op.
104 */
try_utf8_locale(int * pargc,constant char *** pargv)105 static void try_utf8_locale(int *pargc, constant char ***pargv)
106 {
107 char *locale_orig = strdup(setlocale(LC_ALL, NULL));
108 wchar_t **wargv = NULL, *wenv, *wp;
109 constant char **u8argv;
110 char *u8e;
111 int i, n;
112
113 if (!setlocale(LC_ALL, ".UTF8"))
114 goto cleanup; /* not win10 1803+ or not ucrt */
115
116 /*
117 * wargv is before glob expansion. some ucrt builds may expand globs
118 * before main is entered, so n may be smaller than the original argc.
119 * that's ok, because later code at main expands globs anyway.
120 */
121 wargv = CommandLineToArgvW(GetCommandLineW(), &n);
122 if (!wargv)
123 goto bad_args;
124
125 u8argv = (constant char **) ecalloc(n + 1, sizeof(char *));
126 for (i = 0; i < n; ++i)
127 {
128 if (!(u8argv[i] = utf8_from_wide(wargv[i])))
129 goto bad_args;
130 }
131 u8argv[n] = 0;
132
133 less_acp = CP_UTF8;
134 *pargc = n;
135 *pargv = u8argv; /* leaked on exit */
136
137 /* convert wide env to utf8 where we can, but don't abort on errors */
138 if ((wenv = GetEnvironmentStringsW()))
139 {
140 for (wp = wenv; *wp; wp += wcslen(wp) + 1)
141 {
142 if ((u8e = utf8_from_wide(wp)))
143 _putenv(u8e);
144 free(u8e); /* windows putenv makes a copy */
145 }
146 FreeEnvironmentStringsW(wenv);
147 }
148
149 goto cleanup;
150
151 bad_args:
152 error("WARNING: cannot use unicode arguments", NULL_PARG);
153 setlocale(LC_ALL, locale_orig);
154
155 cleanup:
156 free(locale_orig);
157 LocalFree(wargv);
158 }
159 #endif
160
161 #if !SECURE
security_feature_error(constant char * type,size_t len,constant char * name)162 static int security_feature_error(constant char *type, size_t len, constant char *name)
163 {
164 PARG parg;
165 size_t msglen = len + strlen(type) + 64;
166 char *msg = ecalloc(msglen, sizeof(char));
167 SNPRINTF3(msg, msglen, "LESSSECURE_ALLOW: %s feature name \"%.*s\"", type, (int) len, name);
168 parg.p_string = msg;
169 error("%s", &parg);
170 free(msg);
171 return 0;
172 }
173
174 /*
175 * Return the SF_xxx value of a secure feature given the name of the feature.
176 */
security_feature(constant char * name,size_t len)177 static int security_feature(constant char *name, size_t len)
178 {
179 struct secure_feature { constant char *name; int sf_value; };
180 static struct secure_feature features[] = {
181 { "edit", SF_EDIT },
182 { "examine", SF_EXAMINE },
183 { "glob", SF_GLOB },
184 { "history", SF_HISTORY },
185 { "lesskey", SF_LESSKEY },
186 { "lessopen", SF_LESSOPEN },
187 { "logfile", SF_LOGFILE },
188 { "osc8", SF_OSC8_OPEN },
189 { "pipe", SF_PIPE },
190 { "shell", SF_SHELL },
191 { "stop", SF_STOP },
192 { "tags", SF_TAGS },
193 };
194 int i;
195 int match = -1;
196
197 for (i = 0; i < countof(features); i++)
198 {
199 if (strncmp(features[i].name, name, len) == 0)
200 {
201 if (match >= 0) /* name is ambiguous */
202 return security_feature_error("ambiguous", len, name);
203 match = i;
204 }
205 }
206 if (match < 0)
207 return security_feature_error("invalid", len, name);
208 return features[match].sf_value;
209 }
210
set_security_feature(constant char * word,size_t wlen,void * arg)211 static lbool set_security_feature(constant char *word, size_t wlen, void *arg)
212 {
213 secure_allow_features |= security_feature(word, wlen);
214 return TRUE;
215 }
216 #endif /* !SECURE */
217
218 /*
219 * Set the secure_allow_features bitmask, which controls
220 * whether certain secure features are allowed.
221 */
init_secure(void)222 static void init_secure(void)
223 {
224 #if SECURE
225 secure_allow_features = 0;
226 #else
227 constant char *str = lgetenv("LESSSECURE");
228 if (isnullenv(str))
229 secure_allow_features = ~0; /* allow everything */
230 else
231 secure_allow_features = 0; /* allow nothing */
232
233 str = lgetenv("LESSSECURE_ALLOW");
234 if (!isnullenv(str))
235 parse_csl(set_security_feature, str, NULL);
236 #endif
237 }
238
239 /*
240 * Entry point.
241 */
main(int argc,constant char * argv[])242 int main(int argc, constant char *argv[])
243 {
244 IFILE ifile;
245 constant char *s;
246 int i;
247 struct xbuffer xfiles;
248 constant int *files;
249 size_t num_files;
250 size_t f;
251 lbool end_opts = FALSE;
252 lbool posixly_correct;
253
254 no_config = getenv("LESSNOCONFIG");
255
256 #if MSDOS_COMPILER==WIN32C && (defined(__MINGW32__) || defined(_MSC_VER))
257 if (GetACP() != CP_UTF8) /* not using a UTF-8 manifest */
258 try_utf8_locale(&argc, &argv);
259 #endif
260
261 #ifdef __EMX__
262 _response(&argc, &argv);
263 _wildcard(&argc, &argv);
264 #endif
265
266 progname = *argv++;
267 argc--;
268 init_secure();
269
270 #ifdef WIN32
271 if (getenv("HOME") == NULL)
272 {
273 /*
274 * If there is no HOME environment variable,
275 * try the concatenation of HOMEDRIVE + HOMEPATH.
276 */
277 char *drive = getenv("HOMEDRIVE");
278 char *path = getenv("HOMEPATH");
279 if (drive != NULL && path != NULL)
280 {
281 char *env = (char *) ecalloc(strlen(drive) +
282 strlen(path) + 6, sizeof(char));
283 strcpy(env, "HOME=");
284 strcat(env, drive);
285 strcat(env, path);
286 putenv(env);
287 }
288 }
289 /* on failure, consoleTitle is already a valid empty string */
290 GetConsoleTitleW(consoleTitle, countof(consoleTitle));
291 #endif /* WIN32 */
292
293 /*
294 * Process command line arguments and LESS environment arguments.
295 * Command line arguments override environment arguments.
296 */
297 is_tty = isatty(1);
298 init_mark();
299 init_cmds();
300 init_poll();
301 init_charset();
302 init_line();
303 init_cmdhist();
304 init_option();
305 init_search();
306
307 /*
308 * If the name of the executable program is "more",
309 * act like LESS_IS_MORE is set.
310 */
311 if (strcmp(last_component(progname), "more") == 0 &&
312 isnullenv(lgetenv("LESS_IS_MORE"))) {
313 less_is_more = 1;
314 scan_option("-fG", FALSE);
315 }
316
317 init_prompt();
318
319 init_unsupport();
320 s = lgetenv(less_is_more ? "MORE" : "LESS");
321 if (s != NULL)
322 scan_option(s, TRUE);
323
324 #define isoptstring(s) less_is_more ? (((s)[0] == '-') && (s)[1] != '\0') : \
325 (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
326 xbuf_init(&xfiles);
327 posixly_correct = (lgetenv("POSIXLY_CORRECT") != NULL);
328 for (i = 0; i < argc; i++)
329 {
330 if (strcmp(argv[i], "--") == 0)
331 end_opts = TRUE;
332 else if (!end_opts && (isoptstring(argv[i]) || isoptpending()))
333 scan_option(argv[i], FALSE);
334 else
335 {
336 if (posixly_correct)
337 end_opts = TRUE;
338 xbuf_add_data(&xfiles, &i, sizeof(i));
339 }
340 }
341 #undef isoptstring
342
343 if (isoptpending())
344 {
345 /*
346 * Last command line option was a flag requiring a
347 * following string, but there was no following string.
348 */
349 nopendopt();
350 quit(QUIT_OK);
351 }
352
353 if (less_is_more)
354 no_init = TRUE;
355
356 get_term();
357 expand_cmd_tables();
358
359 #if EDITOR
360 editor = lgetenv("VISUAL");
361 if (isnullenv(editor))
362 {
363 editor = lgetenv("EDITOR");
364 if (isnullenv(editor))
365 editor = EDIT_PGM;
366 }
367 editproto = lgetenv("LESSEDIT");
368 if (isnullenv(editproto))
369 editproto = "%E ?lm+%lm. %g";
370 #endif
371
372 /*
373 * Call get_ifile with all the command line filenames
374 * to "register" them with the ifile system.
375 */
376 ifile = NULL_IFILE;
377 if (dohelp)
378 ifile = get_ifile(FAKE_HELPFILE, ifile);
379 files = (constant int *) xfiles.data;
380 num_files = xfiles.end / sizeof(int);
381 for (f = 0; f < num_files; f++)
382 {
383 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
384 /*
385 * Because the "shell" doesn't expand filename patterns,
386 * treat each argument as a filename pattern rather than
387 * a single filename.
388 * Expand the pattern and iterate over the expanded list.
389 */
390 struct textlist tlist;
391 constant char *filename;
392 char *gfilename;
393 char *qfilename;
394
395 gfilename = lglob(argv[files[f]]);
396 init_textlist(&tlist, gfilename);
397 filename = NULL;
398 while ((filename = forw_textlist(&tlist, filename)) != NULL)
399 {
400 qfilename = shell_unquote(filename);
401 (void) get_ifile(qfilename, ifile);
402 free(qfilename);
403 ifile = prev_ifile(NULL_IFILE);
404 }
405 free(gfilename);
406 #else
407 (void) get_ifile(argv[files[f]], ifile);
408 ifile = prev_ifile(NULL_IFILE);
409 #endif
410 }
411 xbuf_deinit(&xfiles);
412
413 /*
414 * Set up terminal, etc.
415 */
416 if (!is_tty)
417 {
418 /*
419 * Output is not a tty.
420 * Just copy the input file(s) to output.
421 */
422 set_output(1, TRUE); /* write to stdout */
423 SET_BINARY(1);
424 if (edit_first() == 0)
425 {
426 do {
427 cat_file();
428 } while (edit_next(1) == 0);
429 }
430 quit(QUIT_OK);
431 }
432
433 if (missing_cap && !know_dumb && !less_is_more)
434 error("WARNING: terminal is not fully functional", NULL_PARG);
435 open_getchr();
436 raw_mode(1);
437 init_signals(1);
438 #if HAVE_TIME
439 less_start_time = get_time();
440 #endif
441
442 /*
443 * Select the first file to examine.
444 */
445 #if TAGS
446 if (tagoption != NULL || strcmp(tags, "-") == 0)
447 {
448 /*
449 * A -t option was given.
450 * Verify that no filenames were also given.
451 * Edit the file selected by the "tags" search,
452 * and search for the proper line in the file.
453 */
454 if (nifile() > 0)
455 {
456 error("No filenames allowed with -t option", NULL_PARG);
457 quit(QUIT_ERROR);
458 }
459 findtag(tagoption);
460 if (edit_tagfile()) /* Edit file which contains the tag */
461 quit(QUIT_ERROR);
462 /*
463 * Search for the line which contains the tag.
464 * Set up initial_scrpos so we display that line.
465 */
466 initial_scrpos.pos = tagsearch();
467 if (initial_scrpos.pos == NULL_POSITION)
468 quit(QUIT_ERROR);
469 initial_scrpos.ln = jump_sline;
470 } else
471 #endif
472 {
473 if (edit_first())
474 quit(QUIT_ERROR);
475 /*
476 * See if file fits on one screen to decide whether
477 * to send terminal init. But don't need this
478 * if -X (no_init) overrides this (see term_init()).
479 */
480 if (quit_if_one_screen)
481 {
482 if (nifile() > 1) /* If more than one file, -F cannot be used */
483 quit_if_one_screen = FALSE;
484 else if (!no_init)
485 one_screen = get_one_screen();
486 }
487 }
488 if (init_header != NULL)
489 {
490 opt_header(TOGGLE, init_header);
491 free(init_header);
492 init_header = NULL;
493 }
494
495 if (errmsgs > 0)
496 {
497 /*
498 * We displayed some messages on error output
499 * (file descriptor 2; see flush()).
500 * Before erasing the screen contents, wait for a keystroke.
501 */
502 less_printf("Press RETURN to continue ", NULL_PARG);
503 get_return();
504 putchr('\n');
505 }
506 set_output(1, FALSE);
507 #if MSDOS_COMPILER
508 term_init();
509 #endif
510 commands();
511 quit(QUIT_OK);
512 /*NOTREACHED*/
513 return (0);
514 }
515
516 /*
517 * Copy a string to a "safe" place
518 * (that is, to a buffer allocated by calloc).
519 */
saven(constant char * s,size_t n)520 public char * saven(constant char *s, size_t n)
521 {
522 char *p = (char *) ecalloc(n+1, sizeof(char));
523 strncpy(p, s, n);
524 p[n] = '\0';
525 return (p);
526 }
527
save(constant char * s)528 public char * save(constant char *s)
529 {
530 return saven(s, strlen(s));
531 }
532
out_of_memory(void)533 public void out_of_memory(void)
534 {
535 error("Cannot allocate memory", NULL_PARG);
536 quit(QUIT_ERROR);
537 }
538
539 /*
540 * Allocate memory.
541 * Like calloc(), but never returns an error (NULL).
542 */
ecalloc(size_t count,size_t size)543 public void * ecalloc(size_t count, size_t size)
544 {
545 void * p;
546
547 p = (void *) calloc(count, size);
548 if (p == NULL)
549 out_of_memory();
550 return p;
551 }
552
553 /*
554 * Skip leading spaces in a string.
555 */
skipsp(char * s)556 public char * skipsp(char *s)
557 {
558 while (*s == ' ' || *s == '\t')
559 s++;
560 return (s);
561 }
562
563 /* {{ There must be a better way. }} */
skipspc(constant char * s)564 public constant char * skipspc(constant char *s)
565 {
566 while (*s == ' ' || *s == '\t')
567 s++;
568 return (s);
569 }
570
571 /*
572 * See how many characters of two strings are identical.
573 * If uppercase is true, the first string must begin with an uppercase
574 * character; the remainder of the first string may be either case.
575 */
sprefix(constant char * ps,constant char * s,int uppercase)576 public size_t sprefix(constant char *ps, constant char *s, int uppercase)
577 {
578 char c;
579 char sc;
580 size_t len = 0;
581
582 for ( ; *s != '\0'; s++, ps++)
583 {
584 c = *ps;
585 if (uppercase)
586 {
587 if (len == 0 && ASCII_IS_LOWER(c))
588 return (0);
589 if (ASCII_IS_UPPER(c))
590 c = ASCII_TO_LOWER(c);
591 }
592 sc = *s;
593 if (len > 0 && ASCII_IS_UPPER(sc))
594 sc = ASCII_TO_LOWER(sc);
595 if (c != sc)
596 break;
597 len++;
598 }
599 return (len);
600 }
601
602 /*
603 * Exit the program.
604 */
quit(int status)605 public void quit(int status)
606 {
607 static int save_status;
608
609 /*
610 * Put cursor at bottom left corner, clear the line,
611 * reset the terminal modes, and exit.
612 */
613 if (status < 0)
614 status = save_status;
615 else
616 save_status = status;
617 quitting = TRUE;
618 check_altpipe_error();
619 if (interactive())
620 clear_bot();
621 term_deinit();
622 flush();
623 if (redraw_on_quit && term_addrs)
624 {
625 /*
626 * The last file text displayed might have been on an
627 * alternate screen, which now (since deinit) cannot be seen.
628 * redraw_on_quit tells us to redraw it on the main screen.
629 */
630 first_time = TRUE; /* Don't print "skipping" or tildes */
631 repaint();
632 flush();
633 }
634 edit((char*)NULL);
635 save_cmdhist();
636 raw_mode(0);
637 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
638 /*
639 * If we don't close 2, we get some garbage from
640 * 2's buffer when it flushes automatically.
641 * I cannot track this one down RB
642 * The same bug shows up if we use ^C^C to abort.
643 */
644 close(2);
645 #endif
646 #ifdef WIN32
647 SetConsoleTitleW(consoleTitle);
648 #endif
649 close_getchr();
650 exit(status);
651 }
652
653 /*
654 * Are all the features in the features mask allowed by security?
655 */
secure_allow(int features)656 public int secure_allow(int features)
657 {
658 return ((secure_allow_features & features) == features);
659 }
660