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