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 lbool 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 static constant char *progname;
40 public lbool quitting = FALSE;
41 public lbool dohelp = FALSE;
42 public char * init_header = NULL;
43 public constant char * no_config = NULL;
44 static unsigned 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 lbool one_screen;
72 extern lbool 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(LM(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 /*
162 * Set the secure_allow_features bitmask, which controls
163 * whether certain secure features are allowed.
164 */
init_secure(void)165 static void init_secure(void)
166 {
167 #if SECURE
168 secure_allow_features = 0;
169 #else
170 static struct csl_bitmap_def security_features[] = {
171 { "edit", SF_EDIT },
172 { "examine", SF_EXAMINE },
173 { "glob", SF_GLOB },
174 { "history", SF_HISTORY },
175 { "lesskey", SF_LESSKEY },
176 { "lessopen", SF_LESSOPEN },
177 { "logfile", SF_LOGFILE },
178 { "osc8", SF_OSC8_OPEN },
179 { "pipe", SF_PIPE },
180 { "shell", SF_SHELL },
181 { "stop", SF_STOP },
182 { "tags", SF_TAGS },
183 };
184 constant char *str = lgetenv("LESSSECURE");
185 if (isnullenv(str))
186 secure_allow_features = ~0; /* allow everything */
187 else
188 secure_allow_features = 0; /* allow nothing */
189
190 str = lgetenv("LESSSECURE_ALLOW");
191 if (!isnullenv(str))
192 secure_allow_features = parse_csl_bitmap(str,
193 security_features, countof(security_features), "LESSSECURE_ALLOW");
194
195 str = lgetenv("LESSSECURE_DISALLOW");
196 if (!isnullenv(str))
197 secure_allow_features &=~ parse_csl_bitmap(str,
198 security_features, countof(security_features), "LESSSECURE_DISALLOW");
199 #endif
200 }
201
202 /*
203 * Entry point.
204 */
main(int argc,constant char * argv[])205 int main(int argc, constant char *argv[])
206 {
207 IFILE ifile;
208 constant char *s;
209 int i;
210 struct xbuffer xfiles;
211 constant int *files;
212 size_t num_files;
213 size_t f;
214 lbool end_opts = FALSE;
215 lbool posixly_correct;
216
217 no_config = lgetenv("LESSNOCONFIG");
218 lmsg_init(lgetenv("LESSMSG"));
219
220 #if MSDOS_COMPILER==WIN32C && (defined(__MINGW32__) || defined(_MSC_VER))
221 if (GetACP() != CP_UTF8) /* not using a UTF-8 manifest */
222 try_utf8_locale(&argc, &argv);
223 #endif
224
225 #ifdef __EMX__
226 _response(&argc, &argv);
227 _wildcard(&argc, &argv);
228 #endif
229
230 progname = *argv++;
231 argc--;
232 init_secure();
233
234 #ifdef WIN32
235 if (lgetenv("HOME") == NULL)
236 {
237 /*
238 * If there is no HOME environment variable,
239 * try the concatenation of HOMEDRIVE + HOMEPATH.
240 */
241 constant char *drive = lgetenv("HOMEDRIVE");
242 constant char *path = lgetenv("HOMEPATH");
243 if (drive != NULL && path != NULL)
244 {
245 char *env = (char *) ecalloc(strlen(drive) +
246 strlen(path) + 6, sizeof(char));
247 strcpy(env, "HOME=");
248 strcat(env, drive);
249 strcat(env, path);
250 putenv(env);
251 }
252 }
253 /* on failure, consoleTitle is already a valid empty string */
254 GetConsoleTitleW(consoleTitle, countof(consoleTitle));
255 #endif /* WIN32 */
256
257 /*
258 * Process command line arguments and LESS environment arguments.
259 * Command line arguments override environment arguments.
260 */
261 is_tty = (isatty(1) != 0);
262 init_mark();
263 init_cmds();
264 init_poll();
265 init_charset();
266 init_line();
267 init_cmdhist();
268 init_option();
269 init_search();
270
271 /*
272 * If the name of the executable program is "more",
273 * act like LESS_IS_MORE is set.
274 */
275 if (strcmp(last_component(progname), "more") == 0 &&
276 isnullenv(lgetenv("LESS_IS_MORE"))) {
277 less_is_more = TRUE;
278 scan_option("-fG", FALSE);
279 }
280
281 init_prompt();
282
283 init_unsupport();
284 s = lgetenv(less_is_more ? "MORE" : "LESS");
285 if (s != NULL)
286 scan_option(s, TRUE);
287
288 #define isoptstring(s) less_is_more ? (((s)[0] == '-') && (s)[1] != '\0') : \
289 (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
290 xbuf_init(&xfiles);
291 /* Don't use lgetenv because POSIXLY_CORRECT is considered to be true
292 * if it is set to an empty string. */
293 posixly_correct = (getenv("POSIXLY_CORRECT") != NULL);
294 for (i = 0; i < argc; i++)
295 {
296 if (strcmp(argv[i], "--") == 0)
297 end_opts = TRUE;
298 else if (!end_opts && (isoptstring(argv[i]) || isoptpending()))
299 scan_option(argv[i], FALSE);
300 else
301 {
302 if (posixly_correct)
303 end_opts = TRUE;
304 xbuf_add_data(&xfiles, &i, sizeof(i));
305 }
306 }
307 #undef isoptstring
308
309 if (isoptpending())
310 {
311 /*
312 * Last command line option was a flag requiring a
313 * following string, but there was no following string.
314 */
315 nopendopt();
316 quit(QUIT_ERROR);
317 }
318
319 if (less_is_more)
320 no_init = TRUE;
321
322 if (is_tty)
323 get_term();
324 expand_cmd_tables();
325
326 #if EDITOR
327 editor = lgetenv("VISUAL");
328 if (isnullenv(editor))
329 {
330 editor = lgetenv("EDITOR");
331 if (isnullenv(editor))
332 editor = EDIT_PGM;
333 }
334 editproto = lgetenv("LESSEDIT");
335 if (isnullenv(editproto))
336 editproto = "%E ?lm+%lm. %g";
337 #endif
338
339 /*
340 * Call get_ifile with all the command line filenames
341 * to "register" them with the ifile system.
342 */
343 ifile = NULL_IFILE;
344 if (dohelp)
345 ifile = get_ifile(FAKE_HELPFILE, ifile);
346 files = (constant int *) xfiles.data;
347 num_files = xfiles.end / sizeof(int);
348 for (f = 0; f < num_files; f++)
349 {
350 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
351 /*
352 * Because the "shell" doesn't expand filename patterns,
353 * treat each argument as a filename pattern rather than
354 * a single filename.
355 * Expand the pattern and iterate over the expanded list.
356 */
357 struct textlist tlist;
358 constant char *filename;
359 char *gfilename;
360 char *qfilename;
361
362 gfilename = lglob(argv[files[f]]);
363 init_textlist(&tlist, gfilename);
364 filename = NULL;
365 while ((filename = forw_textlist(&tlist, filename)) != NULL)
366 {
367 qfilename = shell_unquote(filename);
368 (void) get_ifile(qfilename, ifile);
369 free(qfilename);
370 ifile = prev_ifile(NULL_IFILE);
371 }
372 free(gfilename);
373 #else
374 (void) get_ifile(argv[files[f]], ifile);
375 ifile = prev_ifile(NULL_IFILE);
376 #endif
377 }
378 xbuf_deinit(&xfiles);
379
380 /*
381 * Set up terminal, etc.
382 */
383 if (!is_tty)
384 {
385 /*
386 * Output is not a tty.
387 * Just copy the input file(s) to output.
388 */
389 SET_BINARY(1);
390
391 if (edit_first())
392 quit(QUIT_ERROR);
393
394 set_output(1, TRUE); /* write to stdout */
395 do {
396 cat_file();
397 } while (edit_next(1) == 0);
398
399 quit(QUIT_OK);
400 }
401
402 if (missing_cap && !know_dumb && !less_is_more)
403 error(LM(terminal_is_not_fully_functional), NULL_PARG);
404 open_getchr();
405 init_signals(TRUE);
406 #if HAVE_TIME
407 less_start_time = get_time();
408 #endif
409
410 /*
411 * Select the first file to examine.
412 */
413 #if TAGS
414 if (tagoption != NULL || strcmp(tags, "-") == 0)
415 {
416 /*
417 * A -t option was given.
418 * Verify that no filenames were also given.
419 * Edit the file selected by the "tags" search,
420 * and search for the proper line in the file.
421 */
422 if (nifile() > 0)
423 {
424 error(LM(No_filenames_allowed_with_t_option), NULL_PARG);
425 quit(QUIT_ERROR);
426 }
427 findtag(tagoption);
428 if (edit_tagfile()) /* Edit file which contains the tag */
429 quit(QUIT_ERROR);
430 /*
431 * Search for the line which contains the tag.
432 * Set up initial_scrpos so we display that line.
433 */
434 initial_scrpos.pos = tagsearch();
435 if (initial_scrpos.pos == NULL_POSITION)
436 quit(QUIT_ERROR);
437 initial_scrpos.ln = jump_sline;
438 } else
439 #endif
440 {
441 if (edit_first())
442 quit(QUIT_ERROR);
443 /*
444 * See if file fits on one screen to decide whether
445 * to send terminal init. But don't need this
446 * if -X (no_init) overrides this (see term_init()).
447 */
448 if (quit_if_one_screen)
449 {
450 if (nifile() > 1) /* If more than one file, -F cannot be used */
451 quit_if_one_screen = FALSE;
452 else if (!no_init)
453 one_screen = get_one_screen();
454 }
455 }
456 if (init_header != NULL)
457 {
458 opt_header(TOGGLE, init_header);
459 free(init_header);
460 init_header = NULL;
461 }
462
463 if (errmsgs > 0)
464 {
465 /*
466 * We displayed some messages on error output
467 * (file descriptor 2; see flush()).
468 * Before erasing the screen contents, wait for a keystroke.
469 */
470 PARG parg;
471 parg.p_string = LM(Press_RETURN_to_continue);
472 less_printf("%s", &parg);
473 get_return();
474 putchr('\n');
475 }
476 set_output(1, FALSE);
477 #if MSDOS_COMPILER
478 raw_mode(TRUE);
479 term_init();
480 #endif
481 commands();
482 quit(QUIT_OK);
483 /*NOTREACHED*/
484 return (0);
485 }
486
487 /*
488 * Copy a string to a "safe" place
489 * (that is, to a buffer allocated by calloc).
490 */
saven(constant char * s,size_t n)491 public char * saven(constant char *s, size_t n)
492 {
493 char *p = (char *) ecalloc(n+1, sizeof(char));
494 strncpy(p, s, n);
495 p[n] = '\0';
496 return (p);
497 }
498
save(constant char * s)499 public char * save(constant char *s)
500 {
501 return saven(s, strlen(s));
502 }
503
out_of_memory(void)504 public void out_of_memory(void)
505 {
506 error(LM(Cannot_allocate_memory), NULL_PARG);
507 quit(QUIT_ERROR);
508 }
509
510 /*
511 * Allocate memory.
512 * Like calloc(), but never returns an error (NULL).
513 */
ecalloc(size_t count,size_t size)514 public void * ecalloc(size_t count, size_t size)
515 {
516 void * p;
517
518 p = (void *) calloc(count, size);
519 if (p == NULL)
520 out_of_memory();
521 return p;
522 }
523
524 /*
525 * Skip leading spaces in a string.
526 */
skipsp(char * s)527 public char * skipsp(char *s)
528 {
529 while (*s == ' ' || *s == '\t')
530 s++;
531 return (s);
532 }
533
534 /* {{ There must be a better way. }} */
skipspc(constant char * s)535 public constant char * skipspc(constant char *s)
536 {
537 while (*s == ' ' || *s == '\t')
538 s++;
539 return (s);
540 }
541
542 /*
543 * See how many characters of two strings are identical.
544 * If uppercase is true, the first string must begin with an uppercase
545 * character; the remainder of the first string may be either case.
546 */
sprefix(constant char * ps,constant char * s,int uppercase)547 public size_t sprefix(constant char *ps, constant char *s, int uppercase)
548 {
549 char c;
550 char sc;
551 size_t len = 0;
552
553 for ( ; *s != '\0'; s++, ps++)
554 {
555 c = *ps;
556 if (uppercase)
557 {
558 if (len == 0 && ASCII_IS_LOWER(c))
559 return (0);
560 if (ASCII_IS_UPPER(c))
561 c = ASCII_TO_LOWER(c);
562 }
563 sc = *s;
564 if (len > 0 && ASCII_IS_UPPER(sc))
565 sc = ASCII_TO_LOWER(sc);
566 if (c != sc)
567 break;
568 len++;
569 }
570 return (len);
571 }
572
573 /*
574 * Exit the program.
575 */
quit(int status)576 public void quit(int status)
577 {
578 static int save_status;
579
580 /*
581 * Put cursor at bottom left corner, clear the line,
582 * reset the terminal modes, and exit.
583 */
584 if (status < 0)
585 status = save_status;
586 else
587 save_status = status;
588 quitting = TRUE;
589 check_altpipe_error();
590 if (interactive())
591 clear_bot();
592 term_deinit();
593 flush();
594 if (redraw_on_quit && term_addrs)
595 {
596 /*
597 * The last file text displayed might have been on an
598 * alternate screen, which now (since deinit) cannot be seen.
599 * redraw_on_quit tells us to redraw it on the main screen.
600 */
601 first_time = TRUE; /* Don't print "skipping" or tildes */
602 repaint();
603 flush();
604 }
605 edit((char*)NULL);
606 save_cmdhist();
607 raw_mode(FALSE);
608 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
609 /*
610 * If we don't close 2, we get some garbage from
611 * 2's buffer when it flushes automatically.
612 * I cannot track this one down RB
613 * The same bug shows up if we use ^C^C to abort.
614 */
615 close(2);
616 #endif
617 #ifdef WIN32
618 SetConsoleTitleW(consoleTitle);
619 #endif
620 close_getchr();
621 exit(status);
622 }
623
624 /*
625 * Are all the features in the features mask allowed by security?
626 */
secure_allow(unsigned int features)627 public lbool secure_allow(unsigned int features)
628 {
629 return ((secure_allow_features & features) == features);
630 }
631