1 /*
2 * Copyright (C) 1984-2024 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(MINGW) || 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 public char * every_first_cmd = NULL;
29 public lbool new_file;
30 public int is_tty;
31 public IFILE curr_ifile = NULL_IFILE;
32 public IFILE old_ifile = NULL_IFILE;
33 public struct scrpos initial_scrpos;
34 public POSITION start_attnpos = NULL_POSITION;
35 public POSITION end_attnpos = NULL_POSITION;
36 public int wscroll;
37 public constant char *progname;
38 public int quitting;
39 public int dohelp;
40 static int secure_allow_features;
41
42 #if LOGFILE
43 public int logfile = -1;
44 public lbool force_logfile = FALSE;
45 public char * namelogfile = NULL;
46 #endif
47
48 #if EDITOR
49 public constant char * editor;
50 public constant char * editproto;
51 #endif
52
53 #if TAGS
54 extern char * tags;
55 extern char * tagoption;
56 extern int jump_sline;
57 #endif
58
59 #ifdef WIN32
60 static wchar_t consoleTitle[256];
61 #endif
62
63 public int one_screen;
64 extern int less_is_more;
65 extern int missing_cap;
66 extern int know_dumb;
67 extern int quit_if_one_screen;
68 extern int no_init;
69 extern int errmsgs;
70 extern int redraw_on_quit;
71 extern int term_init_done;
72 extern int first_time;
73
74 #if MSDOS_COMPILER==WIN32C && (defined(MINGW) || defined(_MSC_VER))
75 /* malloc'ed 0-terminated utf8 of 0-terminated wide ws, or null on errors */
utf8_from_wide(constant wchar_t * ws)76 static char *utf8_from_wide(constant wchar_t *ws)
77 {
78 char *u8 = NULL;
79 int n = WideCharToMultiByte(CP_UTF8, 0, ws, -1, NULL, 0, NULL, NULL);
80 if (n > 0)
81 {
82 u8 = ecalloc(n, sizeof(char));
83 WideCharToMultiByte(CP_UTF8, 0, ws, -1, u8, n, NULL, NULL);
84 }
85 return u8;
86 }
87
88 /*
89 * similar to using UTF8 manifest to make the ANSI APIs UTF8, but dynamically
90 * with setlocale. unlike the manifest, argv and environ are already ACP, so
91 * make them UTF8. Additionally, this affects only the libc/crt API, and so
92 * e.g. fopen filename becomes UTF-8, but CreateFileA filename remains CP_ACP.
93 * CP_ACP remains the original codepage - use the dynamic less_acp instead.
94 * effective on win 10 1803 or later when compiled with ucrt, else no-op.
95 */
try_utf8_locale(int * pargc,constant char *** pargv)96 static void try_utf8_locale(int *pargc, constant char ***pargv)
97 {
98 char *locale_orig = strdup(setlocale(LC_ALL, NULL));
99 wchar_t **wargv = NULL, *wenv, *wp;
100 constant char **u8argv;
101 char *u8e;
102 int i, n;
103
104 if (!setlocale(LC_ALL, ".UTF8"))
105 goto cleanup; /* not win10 1803+ or not ucrt */
106
107 /*
108 * wargv is before glob expansion. some ucrt builds may expand globs
109 * before main is entered, so n may be smaller than the original argc.
110 * that's ok, because later code at main expands globs anyway.
111 */
112 wargv = CommandLineToArgvW(GetCommandLineW(), &n);
113 if (!wargv)
114 goto bad_args;
115
116 u8argv = (constant char **) ecalloc(n + 1, sizeof(char *));
117 for (i = 0; i < n; ++i)
118 {
119 if (!(u8argv[i] = utf8_from_wide(wargv[i])))
120 goto bad_args;
121 }
122 u8argv[n] = 0;
123
124 less_acp = CP_UTF8;
125 *pargc = n;
126 *pargv = u8argv; /* leaked on exit */
127
128 /* convert wide env to utf8 where we can, but don't abort on errors */
129 if ((wenv = GetEnvironmentStringsW()))
130 {
131 for (wp = wenv; *wp; wp += wcslen(wp) + 1)
132 {
133 if ((u8e = utf8_from_wide(wp)))
134 _putenv(u8e);
135 free(u8e); /* windows putenv makes a copy */
136 }
137 FreeEnvironmentStringsW(wenv);
138 }
139
140 goto cleanup;
141
142 bad_args:
143 error("WARNING: cannot use unicode arguments", NULL_PARG);
144 setlocale(LC_ALL, locale_orig);
145
146 cleanup:
147 free(locale_orig);
148 LocalFree(wargv);
149 }
150 #endif
151
security_feature_error(constant char * type,size_t len,constant char * name)152 static int security_feature_error(constant char *type, size_t len, constant char *name)
153 {
154 PARG parg;
155 size_t msglen = len + strlen(type) + 64;
156 char *msg = ecalloc(msglen, sizeof(char));
157 SNPRINTF3(msg, msglen, "LESSSECURE_ALLOW: %s feature name \"%.*s\"", type, (int) len, name);
158 parg.p_string = msg;
159 error("%s", &parg);
160 free(msg);
161 return 0;
162 }
163
164 /*
165 * Return the SF_xxx value of a secure feature given the name of the feature.
166 */
security_feature(constant char * name,size_t len)167 static int security_feature(constant char *name, size_t len)
168 {
169 struct secure_feature { constant char *name; int sf_value; };
170 static struct secure_feature 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 int i;
185 int match = -1;
186
187 for (i = 0; i < countof(features); i++)
188 {
189 if (strncmp(features[i].name, name, len) == 0)
190 {
191 if (match >= 0) /* name is ambiguous */
192 return security_feature_error("ambiguous", len, name);
193 match = i;
194 }
195 }
196 if (match < 0)
197 return security_feature_error("invalid", len, name);
198 return features[match].sf_value;
199 }
200
201 /*
202 * Set the secure_allow_features bitmask, which controls
203 * whether certain secure features are allowed.
204 */
init_secure(void)205 static void init_secure(void)
206 {
207 #if SECURE
208 secure_allow_features = 0;
209 #else
210 constant char *str = lgetenv("LESSSECURE");
211 if (isnullenv(str))
212 secure_allow_features = ~0; /* allow everything */
213 else
214 secure_allow_features = 0; /* allow nothing */
215
216 str = lgetenv("LESSSECURE_ALLOW");
217 if (!isnullenv(str))
218 {
219 for (;;)
220 {
221 constant char *estr;
222 while (*str == ' ' || *str == ',') ++str; /* skip leading spaces/commas */
223 if (*str == '\0') break;
224 estr = strchr(str, ',');
225 if (estr == NULL) estr = str + strlen(str);
226 while (estr > str && estr[-1] == ' ') --estr; /* trim trailing spaces */
227 secure_allow_features |= security_feature(str, ptr_diff(estr, str));
228 str = estr;
229 }
230 }
231 #endif
232 }
233
234 /*
235 * Entry point.
236 */
main(int argc,constant char * argv[])237 int main(int argc, constant char *argv[])
238 {
239 IFILE ifile;
240 constant char *s;
241
242 #if MSDOS_COMPILER==WIN32C && (defined(MINGW) || defined(_MSC_VER))
243 if (GetACP() != CP_UTF8) /* not using a UTF-8 manifest */
244 try_utf8_locale(&argc, &argv);
245 #endif
246
247 #ifdef __EMX__
248 _response(&argc, &argv);
249 _wildcard(&argc, &argv);
250 #endif
251
252 progname = *argv++;
253 argc--;
254 init_secure();
255
256 #ifdef WIN32
257 if (getenv("HOME") == NULL)
258 {
259 /*
260 * If there is no HOME environment variable,
261 * try the concatenation of HOMEDRIVE + HOMEPATH.
262 */
263 char *drive = getenv("HOMEDRIVE");
264 char *path = getenv("HOMEPATH");
265 if (drive != NULL && path != NULL)
266 {
267 char *env = (char *) ecalloc(strlen(drive) +
268 strlen(path) + 6, sizeof(char));
269 strcpy(env, "HOME=");
270 strcat(env, drive);
271 strcat(env, path);
272 putenv(env);
273 }
274 }
275 /* on failure, consoleTitle is already a valid empty string */
276 GetConsoleTitleW(consoleTitle, countof(consoleTitle));
277 #endif /* WIN32 */
278
279 /*
280 * Process command line arguments and LESS environment arguments.
281 * Command line arguments override environment arguments.
282 */
283 is_tty = isatty(1);
284 init_mark();
285 init_cmds();
286 init_poll();
287 init_charset();
288 init_line();
289 init_cmdhist();
290 init_option();
291 init_search();
292
293 /*
294 * If the name of the executable program is "more",
295 * act like LESS_IS_MORE is set.
296 */
297 if (strcmp(last_component(progname), "more") == 0)
298 less_is_more = 1;
299
300 init_prompt();
301
302 init_unsupport();
303 s = lgetenv(less_is_more ? "MORE" : "LESS");
304 if (s != NULL)
305 scan_option(s);
306
307 #define isoptstring(s) (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
308 while (argc > 0 && (isoptstring(*argv) || isoptpending()))
309 {
310 s = *argv++;
311 argc--;
312 if (strcmp(s, "--") == 0)
313 break;
314 scan_option(s);
315 }
316 #undef isoptstring
317
318 if (isoptpending())
319 {
320 /*
321 * Last command line option was a flag requiring a
322 * following string, but there was no following string.
323 */
324 nopendopt();
325 quit(QUIT_OK);
326 }
327
328 get_term();
329 expand_cmd_tables();
330
331 #if EDITOR
332 editor = lgetenv("VISUAL");
333 if (editor == NULL || *editor == '\0')
334 {
335 editor = lgetenv("EDITOR");
336 if (isnullenv(editor))
337 editor = EDIT_PGM;
338 }
339 editproto = lgetenv("LESSEDIT");
340 if (isnullenv(editproto))
341 editproto = "%E ?lm+%lm. %g";
342 #endif
343
344 /*
345 * Call get_ifile with all the command line filenames
346 * to "register" them with the ifile system.
347 */
348 ifile = NULL_IFILE;
349 if (dohelp)
350 ifile = get_ifile(FAKE_HELPFILE, ifile);
351 while (argc-- > 0)
352 {
353 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
354 /*
355 * Because the "shell" doesn't expand filename patterns,
356 * treat each argument as a filename pattern rather than
357 * a single filename.
358 * Expand the pattern and iterate over the expanded list.
359 */
360 struct textlist tlist;
361 constant char *filename;
362 char *gfilename;
363 char *qfilename;
364
365 gfilename = lglob(*argv++);
366 init_textlist(&tlist, gfilename);
367 filename = NULL;
368 while ((filename = forw_textlist(&tlist, filename)) != NULL)
369 {
370 qfilename = shell_unquote(filename);
371 (void) get_ifile(qfilename, ifile);
372 free(qfilename);
373 ifile = prev_ifile(NULL_IFILE);
374 }
375 free(gfilename);
376 #else
377 (void) get_ifile(*argv++, ifile);
378 ifile = prev_ifile(NULL_IFILE);
379 #endif
380 }
381 /*
382 * Set up terminal, etc.
383 */
384 if (!is_tty)
385 {
386 /*
387 * Output is not a tty.
388 * Just copy the input file(s) to output.
389 */
390 set_output(1); /* write to stdout */
391 SET_BINARY(1);
392 if (edit_first() == 0)
393 {
394 do {
395 cat_file();
396 } while (edit_next(1) == 0);
397 }
398 quit(QUIT_OK);
399 }
400
401 if (missing_cap && !know_dumb)
402 error("WARNING: terminal is not fully functional", NULL_PARG);
403 open_getchr();
404 raw_mode(1);
405 init_signals(1);
406
407 /*
408 * Select the first file to examine.
409 */
410 #if TAGS
411 if (tagoption != NULL || strcmp(tags, "-") == 0)
412 {
413 /*
414 * A -t option was given.
415 * Verify that no filenames were also given.
416 * Edit the file selected by the "tags" search,
417 * and search for the proper line in the file.
418 */
419 if (nifile() > 0)
420 {
421 error("No filenames allowed with -t option", NULL_PARG);
422 quit(QUIT_ERROR);
423 }
424 findtag(tagoption);
425 if (edit_tagfile()) /* Edit file which contains the tag */
426 quit(QUIT_ERROR);
427 /*
428 * Search for the line which contains the tag.
429 * Set up initial_scrpos so we display that line.
430 */
431 initial_scrpos.pos = tagsearch();
432 if (initial_scrpos.pos == NULL_POSITION)
433 quit(QUIT_ERROR);
434 initial_scrpos.ln = jump_sline;
435 } else
436 #endif
437 {
438 if (edit_first())
439 quit(QUIT_ERROR);
440 /*
441 * See if file fits on one screen to decide whether
442 * to send terminal init. But don't need this
443 * if -X (no_init) overrides this (see init()).
444 */
445 if (quit_if_one_screen)
446 {
447 if (nifile() > 1) /* If more than one file, -F cannot be used */
448 quit_if_one_screen = FALSE;
449 else if (!no_init)
450 one_screen = get_one_screen();
451 }
452 }
453
454 if (errmsgs > 0)
455 {
456 /*
457 * We displayed some messages on error output
458 * (file descriptor 2; see flush()).
459 * Before erasing the screen contents, wait for a keystroke.
460 */
461 less_printf("Press RETURN to continue ", NULL_PARG);
462 get_return();
463 putchr('\n');
464 }
465 set_output(1);
466 init();
467 commands();
468 quit(QUIT_OK);
469 /*NOTREACHED*/
470 return (0);
471 }
472
473 /*
474 * Copy a string to a "safe" place
475 * (that is, to a buffer allocated by calloc).
476 */
saven(constant char * s,size_t n)477 public char * saven(constant char *s, size_t n)
478 {
479 char *p = (char *) ecalloc(n+1, sizeof(char));
480 strncpy(p, s, n);
481 p[n] = '\0';
482 return (p);
483 }
484
save(constant char * s)485 public char * save(constant char *s)
486 {
487 return saven(s, strlen(s));
488 }
489
out_of_memory(void)490 public void out_of_memory(void)
491 {
492 error("Cannot allocate memory", NULL_PARG);
493 quit(QUIT_ERROR);
494 }
495
496 /*
497 * Allocate memory.
498 * Like calloc(), but never returns an error (NULL).
499 */
ecalloc(size_t count,size_t size)500 public void * ecalloc(size_t count, size_t size)
501 {
502 void * p;
503
504 p = (void *) calloc(count, size);
505 if (p == NULL)
506 out_of_memory();
507 return p;
508 }
509
510 /*
511 * Skip leading spaces in a string.
512 */
skipsp(char * s)513 public char * skipsp(char *s)
514 {
515 while (*s == ' ' || *s == '\t')
516 s++;
517 return (s);
518 }
519
520 /* {{ There must be a better way. }} */
skipspc(constant char * s)521 public constant char * skipspc(constant char *s)
522 {
523 while (*s == ' ' || *s == '\t')
524 s++;
525 return (s);
526 }
527
528 /*
529 * See how many characters of two strings are identical.
530 * If uppercase is true, the first string must begin with an uppercase
531 * character; the remainder of the first string may be either case.
532 */
sprefix(constant char * ps,constant char * s,int uppercase)533 public size_t sprefix(constant char *ps, constant char *s, int uppercase)
534 {
535 char c;
536 char sc;
537 size_t len = 0;
538
539 for ( ; *s != '\0'; s++, ps++)
540 {
541 c = *ps;
542 if (uppercase)
543 {
544 if (len == 0 && ASCII_IS_LOWER(c))
545 return (0);
546 if (ASCII_IS_UPPER(c))
547 c = ASCII_TO_LOWER(c);
548 }
549 sc = *s;
550 if (len > 0 && ASCII_IS_UPPER(sc))
551 sc = ASCII_TO_LOWER(sc);
552 if (c != sc)
553 break;
554 len++;
555 }
556 return (len);
557 }
558
559 /*
560 * Exit the program.
561 */
quit(int status)562 public void quit(int status)
563 {
564 static int save_status;
565
566 /*
567 * Put cursor at bottom left corner, clear the line,
568 * reset the terminal modes, and exit.
569 */
570 if (status < 0)
571 status = save_status;
572 else
573 save_status = status;
574 quitting = 1;
575 check_altpipe_error();
576 if (interactive())
577 clear_bot();
578 deinit();
579 flush();
580 if (redraw_on_quit && term_init_done)
581 {
582 /*
583 * The last file text displayed might have been on an
584 * alternate screen, which now (since deinit) cannot be seen.
585 * redraw_on_quit tells us to redraw it on the main screen.
586 */
587 first_time = 1; /* Don't print "skipping" or tildes */
588 repaint();
589 flush();
590 }
591 edit((char*)NULL);
592 save_cmdhist();
593 raw_mode(0);
594 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
595 /*
596 * If we don't close 2, we get some garbage from
597 * 2's buffer when it flushes automatically.
598 * I cannot track this one down RB
599 * The same bug shows up if we use ^C^C to abort.
600 */
601 close(2);
602 #endif
603 #ifdef WIN32
604 SetConsoleTitleW(consoleTitle);
605 #endif
606 close_getchr();
607 exit(status);
608 }
609
610 /*
611 * Are all the features in the features mask allowed by security?
612 */
secure_allow(int features)613 public int secure_allow(int features)
614 {
615 return ((secure_allow_features & features) == features);
616 }
617