1 /* $FreeBSD$ */
2 /*
3 * Copyright (C) 1984-2024 Mark Nudelman
4 *
5 * You may distribute under the terms of either the GNU General Public
6 * License or the Less License, as specified in the README file.
7 *
8 * For more information, see the README file.
9 */
10
11
12 /*
13 * Entry point, initialization, miscellaneous routines.
14 */
15
16 #include "less.h"
17 #if MSDOS_COMPILER==WIN32C
18 #define WIN32_LEAN_AND_MEAN
19 #include <windows.h>
20
21 #if defined(MINGW) || defined(_MSC_VER)
22 #include <locale.h>
23 #include <shellapi.h>
24 #endif
25
26 public unsigned less_acp = CP_ACP;
27 #endif
28
29 #include "option.h"
30
31 public char * every_first_cmd = NULL;
32 public lbool new_file;
33 public int is_tty;
34 public IFILE curr_ifile = NULL_IFILE;
35 public IFILE old_ifile = NULL_IFILE;
36 public struct scrpos initial_scrpos;
37 public POSITION start_attnpos = NULL_POSITION;
38 public POSITION end_attnpos = NULL_POSITION;
39 public int wscroll;
40 public constant char *progname;
41 public int quitting;
42 public int dohelp;
43 public char * init_header = 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 #ifdef WIN32
64 static wchar_t consoleTitle[256];
65 #endif
66
67 public int one_screen;
68 extern int less_is_more;
69 extern int missing_cap;
70 extern int know_dumb;
71 extern int quit_if_one_screen;
72 extern int no_init;
73 extern int errmsgs;
74 extern int redraw_on_quit;
75 extern int term_init_done;
76 extern int first_time;
77
78 #if MSDOS_COMPILER==WIN32C && (defined(MINGW) || defined(_MSC_VER))
79 /* malloc'ed 0-terminated utf8 of 0-terminated wide ws, or null on errors */
utf8_from_wide(constant wchar_t * ws)80 static char *utf8_from_wide(constant wchar_t *ws)
81 {
82 char *u8 = NULL;
83 int n = WideCharToMultiByte(CP_UTF8, 0, ws, -1, NULL, 0, NULL, NULL);
84 if (n > 0)
85 {
86 u8 = ecalloc(n, sizeof(char));
87 WideCharToMultiByte(CP_UTF8, 0, ws, -1, u8, n, NULL, NULL);
88 }
89 return u8;
90 }
91
92 /*
93 * similar to using UTF8 manifest to make the ANSI APIs UTF8, but dynamically
94 * with setlocale. unlike the manifest, argv and environ are already ACP, so
95 * make them UTF8. Additionally, this affects only the libc/crt API, and so
96 * e.g. fopen filename becomes UTF-8, but CreateFileA filename remains CP_ACP.
97 * CP_ACP remains the original codepage - use the dynamic less_acp instead.
98 * effective on win 10 1803 or later when compiled with ucrt, else no-op.
99 */
try_utf8_locale(int * pargc,constant char *** pargv)100 static void try_utf8_locale(int *pargc, constant char ***pargv)
101 {
102 char *locale_orig = strdup(setlocale(LC_ALL, NULL));
103 wchar_t **wargv = NULL, *wenv, *wp;
104 constant char **u8argv;
105 char *u8e;
106 int i, n;
107
108 if (!setlocale(LC_ALL, ".UTF8"))
109 goto cleanup; /* not win10 1803+ or not ucrt */
110
111 /*
112 * wargv is before glob expansion. some ucrt builds may expand globs
113 * before main is entered, so n may be smaller than the original argc.
114 * that's ok, because later code at main expands globs anyway.
115 */
116 wargv = CommandLineToArgvW(GetCommandLineW(), &n);
117 if (!wargv)
118 goto bad_args;
119
120 u8argv = (constant char **) ecalloc(n + 1, sizeof(char *));
121 for (i = 0; i < n; ++i)
122 {
123 if (!(u8argv[i] = utf8_from_wide(wargv[i])))
124 goto bad_args;
125 }
126 u8argv[n] = 0;
127
128 less_acp = CP_UTF8;
129 *pargc = n;
130 *pargv = u8argv; /* leaked on exit */
131
132 /* convert wide env to utf8 where we can, but don't abort on errors */
133 if ((wenv = GetEnvironmentStringsW()))
134 {
135 for (wp = wenv; *wp; wp += wcslen(wp) + 1)
136 {
137 if ((u8e = utf8_from_wide(wp)))
138 _putenv(u8e);
139 free(u8e); /* windows putenv makes a copy */
140 }
141 FreeEnvironmentStringsW(wenv);
142 }
143
144 goto cleanup;
145
146 bad_args:
147 error("WARNING: cannot use unicode arguments", NULL_PARG);
148 setlocale(LC_ALL, locale_orig);
149
150 cleanup:
151 free(locale_orig);
152 LocalFree(wargv);
153 }
154 #endif
155
security_feature_error(constant char * type,size_t len,constant char * name)156 static int security_feature_error(constant char *type, size_t len, constant char *name)
157 {
158 PARG parg;
159 size_t msglen = len + strlen(type) + 64;
160 char *msg = ecalloc(msglen, sizeof(char));
161 SNPRINTF3(msg, msglen, "LESSSECURE_ALLOW: %s feature name \"%.*s\"", type, (int) len, name);
162 parg.p_string = msg;
163 error("%s", &parg);
164 free(msg);
165 return 0;
166 }
167
168 /*
169 * Return the SF_xxx value of a secure feature given the name of the feature.
170 */
security_feature(constant char * name,size_t len)171 static int security_feature(constant char *name, size_t len)
172 {
173 struct secure_feature { constant char *name; int sf_value; };
174 static struct secure_feature features[] = {
175 { "edit", SF_EDIT },
176 { "examine", SF_EXAMINE },
177 { "glob", SF_GLOB },
178 { "history", SF_HISTORY },
179 { "lesskey", SF_LESSKEY },
180 { "lessopen", SF_LESSOPEN },
181 { "logfile", SF_LOGFILE },
182 { "osc8", SF_OSC8_OPEN },
183 { "pipe", SF_PIPE },
184 { "shell", SF_SHELL },
185 { "stop", SF_STOP },
186 { "tags", SF_TAGS },
187 };
188 int i;
189 int match = -1;
190
191 for (i = 0; i < countof(features); i++)
192 {
193 if (strncmp(features[i].name, name, len) == 0)
194 {
195 if (match >= 0) /* name is ambiguous */
196 return security_feature_error("ambiguous", len, name);
197 match = i;
198 }
199 }
200 if (match < 0)
201 return security_feature_error("invalid", len, name);
202 return features[match].sf_value;
203 }
204
205 /*
206 * Set the secure_allow_features bitmask, which controls
207 * whether certain secure features are allowed.
208 */
init_secure(void)209 static void init_secure(void)
210 {
211 #if SECURE
212 secure_allow_features = 0;
213 #else
214 constant char *str = lgetenv("LESSSECURE");
215 if (isnullenv(str))
216 secure_allow_features = ~0; /* allow everything */
217 else
218 secure_allow_features = 0; /* allow nothing */
219
220 str = lgetenv("LESSSECURE_ALLOW");
221 if (!isnullenv(str))
222 {
223 for (;;)
224 {
225 constant char *estr;
226 while (*str == ' ' || *str == ',') ++str; /* skip leading spaces/commas */
227 if (*str == '\0') break;
228 estr = strchr(str, ',');
229 if (estr == NULL) estr = str + strlen(str);
230 while (estr > str && estr[-1] == ' ') --estr; /* trim trailing spaces */
231 secure_allow_features |= security_feature(str, ptr_diff(estr, str));
232 str = estr;
233 }
234 }
235 #endif
236 }
237
238 /*
239 * Entry point.
240 */
main(int argc,constant char * argv[])241 int main(int argc, constant char *argv[])
242 {
243 IFILE ifile;
244 constant char *s;
245
246 #if MSDOS_COMPILER==WIN32C && (defined(MINGW) || defined(_MSC_VER))
247 if (GetACP() != CP_UTF8) /* not using a UTF-8 manifest */
248 try_utf8_locale(&argc, &argv);
249 #endif
250
251 #ifdef __EMX__
252 _response(&argc, &argv);
253 _wildcard(&argc, &argv);
254 #endif
255
256 progname = *argv++;
257 argc--;
258 init_secure();
259
260 #ifdef WIN32
261 if (getenv("HOME") == NULL)
262 {
263 /*
264 * If there is no HOME environment variable,
265 * try the concatenation of HOMEDRIVE + HOMEPATH.
266 */
267 char *drive = getenv("HOMEDRIVE");
268 char *path = getenv("HOMEPATH");
269 if (drive != NULL && path != NULL)
270 {
271 char *env = (char *) ecalloc(strlen(drive) +
272 strlen(path) + 6, sizeof(char));
273 strcpy(env, "HOME=");
274 strcat(env, drive);
275 strcat(env, path);
276 putenv(env);
277 }
278 }
279 /* on failure, consoleTitle is already a valid empty string */
280 GetConsoleTitleW(consoleTitle, countof(consoleTitle));
281 #endif /* WIN32 */
282
283 /*
284 * Process command line arguments and LESS environment arguments.
285 * Command line arguments override environment arguments.
286 */
287 is_tty = isatty(1);
288 init_mark();
289 init_cmds();
290 init_poll();
291 init_charset();
292 init_line();
293 init_cmdhist();
294 init_option();
295 init_search();
296
297 /*
298 * If the name of the executable program is "more",
299 * act like LESS_IS_MORE is set.
300 */
301 if (strcmp(last_component(progname), "more") == 0) {
302 less_is_more = 1;
303 scan_option("-fG");
304 }
305
306 init_prompt();
307
308 init_unsupport();
309 s = lgetenv(less_is_more ? "MORE" : "LESS");
310 if (s != NULL)
311 scan_option(s);
312
313 #define isoptstring(s) less_is_more ? (((s)[0] == '-') && (s)[1] != '\0') : \
314 (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
315 while (argc > 0 && (isoptstring(*argv) || isoptpending()))
316 {
317 s = *argv++;
318 argc--;
319 if (strcmp(s, "--") == 0)
320 break;
321 scan_option(s);
322 }
323 #undef isoptstring
324
325 if (isoptpending())
326 {
327 /*
328 * Last command line option was a flag requiring a
329 * following string, but there was no following string.
330 */
331 nopendopt();
332 quit(QUIT_OK);
333 }
334
335 if (less_is_more)
336 no_init = TRUE;
337
338 get_term();
339 expand_cmd_tables();
340
341 #if EDITOR
342 editor = lgetenv("VISUAL");
343 if (editor == NULL || *editor == '\0')
344 {
345 editor = lgetenv("EDITOR");
346 if (isnullenv(editor))
347 editor = EDIT_PGM;
348 }
349 editproto = lgetenv("LESSEDIT");
350 if (isnullenv(editproto))
351 editproto = "%E ?lm+%lm. %g";
352 #endif
353
354 /*
355 * Call get_ifile with all the command line filenames
356 * to "register" them with the ifile system.
357 */
358 ifile = NULL_IFILE;
359 if (dohelp)
360 ifile = get_ifile(FAKE_HELPFILE, ifile);
361 while (argc-- > 0)
362 {
363 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
364 /*
365 * Because the "shell" doesn't expand filename patterns,
366 * treat each argument as a filename pattern rather than
367 * a single filename.
368 * Expand the pattern and iterate over the expanded list.
369 */
370 struct textlist tlist;
371 constant char *filename;
372 char *gfilename;
373 char *qfilename;
374
375 gfilename = lglob(*argv++);
376 init_textlist(&tlist, gfilename);
377 filename = NULL;
378 while ((filename = forw_textlist(&tlist, filename)) != NULL)
379 {
380 qfilename = shell_unquote(filename);
381 (void) get_ifile(qfilename, ifile);
382 free(qfilename);
383 ifile = prev_ifile(NULL_IFILE);
384 }
385 free(gfilename);
386 #else
387 (void) get_ifile(*argv++, ifile);
388 ifile = prev_ifile(NULL_IFILE);
389 #endif
390 }
391 /*
392 * Set up terminal, etc.
393 */
394 if (!is_tty)
395 {
396 /*
397 * Output is not a tty.
398 * Just copy the input file(s) to output.
399 */
400 set_output(1); /* write to stdout */
401 SET_BINARY(1);
402 if (edit_first() == 0)
403 {
404 do {
405 cat_file();
406 } while (edit_next(1) == 0);
407 }
408 quit(QUIT_OK);
409 }
410
411 if (missing_cap && !know_dumb && !less_is_more)
412 error("WARNING: terminal is not fully functional", NULL_PARG);
413 open_getchr();
414 raw_mode(1);
415 init_signals(1);
416
417 /*
418 * Select the first file to examine.
419 */
420 #if TAGS
421 if (tagoption != NULL || strcmp(tags, "-") == 0)
422 {
423 /*
424 * A -t option was given.
425 * Verify that no filenames were also given.
426 * Edit the file selected by the "tags" search,
427 * and search for the proper line in the file.
428 */
429 if (nifile() > 0)
430 {
431 error("No filenames allowed with -t option", NULL_PARG);
432 quit(QUIT_ERROR);
433 }
434 findtag(tagoption);
435 if (edit_tagfile()) /* Edit file which contains the tag */
436 quit(QUIT_ERROR);
437 /*
438 * Search for the line which contains the tag.
439 * Set up initial_scrpos so we display that line.
440 */
441 initial_scrpos.pos = tagsearch();
442 if (initial_scrpos.pos == NULL_POSITION)
443 quit(QUIT_ERROR);
444 initial_scrpos.ln = jump_sline;
445 } else
446 #endif
447 {
448 if (edit_first())
449 quit(QUIT_ERROR);
450 /*
451 * See if file fits on one screen to decide whether
452 * to send terminal init. But don't need this
453 * if -X (no_init) overrides this (see init()).
454 */
455 if (quit_if_one_screen)
456 {
457 if (nifile() > 1) /* If more than one file, -F cannot be used */
458 quit_if_one_screen = FALSE;
459 else if (!no_init)
460 one_screen = get_one_screen();
461 }
462 }
463 if (init_header != NULL)
464 {
465 opt_header(TOGGLE, init_header);
466 free(init_header);
467 init_header = NULL;
468 }
469
470 if (errmsgs > 0)
471 {
472 /*
473 * We displayed some messages on error output
474 * (file descriptor 2; see flush()).
475 * Before erasing the screen contents, wait for a keystroke.
476 */
477 less_printf("Press RETURN to continue ", NULL_PARG);
478 get_return();
479 putchr('\n');
480 }
481 set_output(1);
482 init();
483 commands();
484 quit(QUIT_OK);
485 /*NOTREACHED*/
486 return (0);
487 }
488
489 /*
490 * Copy a string to a "safe" place
491 * (that is, to a buffer allocated by calloc).
492 */
saven(constant char * s,size_t n)493 public char * saven(constant char *s, size_t n)
494 {
495 char *p = (char *) ecalloc(n+1, sizeof(char));
496 strncpy(p, s, n);
497 p[n] = '\0';
498 return (p);
499 }
500
save(constant char * s)501 public char * save(constant char *s)
502 {
503 return saven(s, strlen(s));
504 }
505
out_of_memory(void)506 public void out_of_memory(void)
507 {
508 error("Cannot allocate memory", NULL_PARG);
509 quit(QUIT_ERROR);
510 }
511
512 /*
513 * Allocate memory.
514 * Like calloc(), but never returns an error (NULL).
515 */
ecalloc(size_t count,size_t size)516 public void * ecalloc(size_t count, size_t size)
517 {
518 void * p;
519
520 p = (void *) calloc(count, size);
521 if (p == NULL)
522 out_of_memory();
523 return p;
524 }
525
526 /*
527 * Skip leading spaces in a string.
528 */
skipsp(char * s)529 public char * skipsp(char *s)
530 {
531 while (*s == ' ' || *s == '\t')
532 s++;
533 return (s);
534 }
535
536 /* {{ There must be a better way. }} */
skipspc(constant char * s)537 public constant char * skipspc(constant char *s)
538 {
539 while (*s == ' ' || *s == '\t')
540 s++;
541 return (s);
542 }
543
544 /*
545 * See how many characters of two strings are identical.
546 * If uppercase is true, the first string must begin with an uppercase
547 * character; the remainder of the first string may be either case.
548 */
sprefix(constant char * ps,constant char * s,int uppercase)549 public size_t sprefix(constant char *ps, constant char *s, int uppercase)
550 {
551 char c;
552 char sc;
553 size_t len = 0;
554
555 for ( ; *s != '\0'; s++, ps++)
556 {
557 c = *ps;
558 if (uppercase)
559 {
560 if (len == 0 && ASCII_IS_LOWER(c))
561 return (0);
562 if (ASCII_IS_UPPER(c))
563 c = ASCII_TO_LOWER(c);
564 }
565 sc = *s;
566 if (len > 0 && ASCII_IS_UPPER(sc))
567 sc = ASCII_TO_LOWER(sc);
568 if (c != sc)
569 break;
570 len++;
571 }
572 return (len);
573 }
574
575 /*
576 * Exit the program.
577 */
quit(int status)578 public void quit(int status)
579 {
580 static int save_status;
581
582 /*
583 * Put cursor at bottom left corner, clear the line,
584 * reset the terminal modes, and exit.
585 */
586 if (status < 0)
587 status = save_status;
588 else
589 save_status = status;
590 quitting = 1;
591 check_altpipe_error();
592 if (interactive())
593 clear_bot();
594 deinit();
595 flush();
596 if (redraw_on_quit && term_init_done)
597 {
598 /*
599 * The last file text displayed might have been on an
600 * alternate screen, which now (since deinit) cannot be seen.
601 * redraw_on_quit tells us to redraw it on the main screen.
602 */
603 first_time = 1; /* Don't print "skipping" or tildes */
604 repaint();
605 flush();
606 }
607 edit((char*)NULL);
608 save_cmdhist();
609 raw_mode(0);
610 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
611 /*
612 * If we don't close 2, we get some garbage from
613 * 2's buffer when it flushes automatically.
614 * I cannot track this one down RB
615 * The same bug shows up if we use ^C^C to abort.
616 */
617 close(2);
618 #endif
619 #ifdef WIN32
620 SetConsoleTitleW(consoleTitle);
621 #endif
622 close_getchr();
623 exit(status);
624 }
625
626 /*
627 * Are all the features in the features mask allowed by security?
628 */
secure_allow(int features)629 public int secure_allow(int features)
630 {
631 return ((secure_allow_features & features) == features);
632 }
633