xref: /freebsd/contrib/less/main.c (revision ec965063070e5753c166cf592c9336444b74720a)
1 /* $FreeBSD$ */
2 /*
3  * Copyright (C) 1984-2022  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 #endif
21 
22 public char *   every_first_cmd = NULL;
23 public int      new_file;
24 public int      is_tty;
25 public IFILE    curr_ifile = NULL_IFILE;
26 public IFILE    old_ifile = NULL_IFILE;
27 public struct scrpos initial_scrpos;
28 public POSITION start_attnpos = NULL_POSITION;
29 public POSITION end_attnpos = NULL_POSITION;
30 public int      wscroll;
31 public char *   progname;
32 public int      quitting;
33 public int      secure;
34 public int      dohelp;
35 
36 #if LOGFILE
37 public int      logfile = -1;
38 public int      force_logfile = FALSE;
39 public char *   namelogfile = NULL;
40 #endif
41 
42 #if EDITOR
43 public char *   editor;
44 public char *   editproto;
45 #endif
46 
47 #if TAGS
48 extern char *   tags;
49 extern char *   tagoption;
50 extern int      jump_sline;
51 #endif
52 
53 #ifdef WIN32
54 static char consoleTitle[256];
55 #endif
56 
57 public int      one_screen;
58 extern int      less_is_more;
59 extern int      missing_cap;
60 extern int      know_dumb;
61 extern int      pr_type;
62 extern int      quit_if_one_screen;
63 extern int      no_init;
64 extern int      errmsgs;
65 extern int      redraw_on_quit;
66 extern int      term_init_done;
67 extern int      first_time;
68 
69 /*
70  * Entry point.
71  */
72 int
73 main(argc, argv)
74 	int argc;
75 	char *argv[];
76 {
77 	IFILE ifile;
78 	char *s;
79 
80 #ifdef __EMX__
81 	_response(&argc, &argv);
82 	_wildcard(&argc, &argv);
83 #endif
84 
85 	progname = *argv++;
86 	argc--;
87 
88 #if SECURE
89 	secure = 1;
90 #else
91 	secure = 0;
92 	s = lgetenv("LESSSECURE");
93 	if (!isnullenv(s))
94 		secure = 1;
95 #endif
96 
97 #ifdef WIN32
98 	if (getenv("HOME") == NULL)
99 	{
100 		/*
101 		 * If there is no HOME environment variable,
102 		 * try the concatenation of HOMEDRIVE + HOMEPATH.
103 		 */
104 		char *drive = getenv("HOMEDRIVE");
105 		char *path  = getenv("HOMEPATH");
106 		if (drive != NULL && path != NULL)
107 		{
108 			char *env = (char *) ecalloc(strlen(drive) +
109 					strlen(path) + 6, sizeof(char));
110 			strcpy(env, "HOME=");
111 			strcat(env, drive);
112 			strcat(env, path);
113 			putenv(env);
114 		}
115 	}
116 	GetConsoleTitle(consoleTitle, sizeof(consoleTitle)/sizeof(char));
117 #endif /* WIN32 */
118 
119 	/*
120 	 * Process command line arguments and LESS environment arguments.
121 	 * Command line arguments override environment arguments.
122 	 */
123 	is_tty = isatty(1);
124 	init_mark();
125 	init_cmds();
126 	get_term();
127 	init_charset();
128 	init_line();
129 	init_cmdhist();
130 	init_option();
131 	init_search();
132 
133 	/*
134 	 * If the name of the executable program is "more",
135 	 * act like LESS_IS_MORE is set.
136 	 */
137 	s = last_component(progname);
138 	if (strcmp(s, "more") == 0)
139 		less_is_more = 1;
140 
141 	init_prompt();
142 
143 	if (less_is_more)
144 		scan_option("-fG");
145 
146 	s = lgetenv(less_is_more ? "MORE" : "LESS");
147 	if (s != NULL)
148 		scan_option(s);
149 
150 #define isoptstring(s)  less_is_more ? (((s)[0] == '-') && (s)[1] != '\0') : \
151 			(((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
152 	while (argc > 0 && (isoptstring(*argv) || isoptpending()))
153 	{
154 		s = *argv++;
155 		argc--;
156 		if (strcmp(s, "--") == 0)
157 			break;
158 		scan_option(s);
159 	}
160 #undef isoptstring
161 
162 	if (isoptpending())
163 	{
164 		/*
165 		 * Last command line option was a flag requiring a
166 		 * following string, but there was no following string.
167 		 */
168 		nopendopt();
169 		quit(QUIT_OK);
170 	}
171 
172 	if (less_is_more)
173 		no_init = TRUE;
174 
175 	expand_cmd_tables();
176 
177 #if EDITOR
178 	editor = lgetenv("VISUAL");
179 	if (editor == NULL || *editor == '\0')
180 	{
181 		editor = lgetenv("EDITOR");
182 		if (isnullenv(editor))
183 			editor = EDIT_PGM;
184 	}
185 	editproto = lgetenv("LESSEDIT");
186 	if (isnullenv(editproto))
187 		editproto = "%E ?lm+%lm. %g";
188 #endif
189 
190 	/*
191 	 * Call get_ifile with all the command line filenames
192 	 * to "register" them with the ifile system.
193 	 */
194 	ifile = NULL_IFILE;
195 	if (dohelp)
196 		ifile = get_ifile(FAKE_HELPFILE, ifile);
197 	while (argc-- > 0)
198 	{
199 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
200 		/*
201 		 * Because the "shell" doesn't expand filename patterns,
202 		 * treat each argument as a filename pattern rather than
203 		 * a single filename.
204 		 * Expand the pattern and iterate over the expanded list.
205 		 */
206 		struct textlist tlist;
207 		char *filename;
208 		char *gfilename;
209 		char *qfilename;
210 
211 		gfilename = lglob(*argv++);
212 		init_textlist(&tlist, gfilename);
213 		filename = NULL;
214 		while ((filename = forw_textlist(&tlist, filename)) != NULL)
215 		{
216 			qfilename = shell_unquote(filename);
217 			(void) get_ifile(qfilename, ifile);
218 			free(qfilename);
219 			ifile = prev_ifile(NULL_IFILE);
220 		}
221 		free(gfilename);
222 #else
223 		(void) get_ifile(*argv++, ifile);
224 		ifile = prev_ifile(NULL_IFILE);
225 #endif
226 	}
227 	/*
228 	 * Set up terminal, etc.
229 	 */
230 	if (!is_tty)
231 	{
232 		/*
233 		 * Output is not a tty.
234 		 * Just copy the input file(s) to output.
235 		 */
236 		set_output(1); /* write to stdout */
237 		SET_BINARY(1);
238 		if (edit_first() == 0)
239 		{
240 			do {
241 				cat_file();
242 			} while (edit_next(1) == 0);
243 		}
244 		quit(QUIT_OK);
245 	}
246 
247 	if (missing_cap && !know_dumb && !less_is_more)
248 		error("WARNING: terminal is not fully functional", NULL_PARG);
249 	open_getchr();
250 	raw_mode(1);
251 	init_signals(1);
252 
253 	/*
254 	 * Select the first file to examine.
255 	 */
256 #if TAGS
257 	if (tagoption != NULL || strcmp(tags, "-") == 0)
258 	{
259 		/*
260 		 * A -t option was given.
261 		 * Verify that no filenames were also given.
262 		 * Edit the file selected by the "tags" search,
263 		 * and search for the proper line in the file.
264 		 */
265 		if (nifile() > 0)
266 		{
267 			error("No filenames allowed with -t option", NULL_PARG);
268 			quit(QUIT_ERROR);
269 		}
270 		findtag(tagoption);
271 		if (edit_tagfile())  /* Edit file which contains the tag */
272 			quit(QUIT_ERROR);
273 		/*
274 		 * Search for the line which contains the tag.
275 		 * Set up initial_scrpos so we display that line.
276 		 */
277 		initial_scrpos.pos = tagsearch();
278 		if (initial_scrpos.pos == NULL_POSITION)
279 			quit(QUIT_ERROR);
280 		initial_scrpos.ln = jump_sline;
281 	} else
282 #endif
283 	{
284 		if (edit_first())
285 			quit(QUIT_ERROR);
286 		/*
287 		 * See if file fits on one screen to decide whether
288 		 * to send terminal init. But don't need this
289 		 * if -X (no_init) overrides this (see init()).
290 		 */
291 		if (quit_if_one_screen)
292 		{
293 			if (nifile() > 1) /* If more than one file, -F cannot be used */
294 				quit_if_one_screen = FALSE;
295 			else if (!no_init)
296 				one_screen = get_one_screen();
297 		}
298 	}
299 
300 	if (errmsgs > 0)
301 	{
302 		/*
303 		 * We displayed some messages on error output
304 		 * (file descriptor 2; see flush()).
305 		 * Before erasing the screen contents, wait for a keystroke.
306 		 */
307 		less_printf("Press RETURN to continue ", NULL_PARG);
308 		get_return();
309 		putchr('\n');
310 	}
311 	set_output(1);
312 	init();
313 	commands();
314 	quit(QUIT_OK);
315 	/*NOTREACHED*/
316 	return (0);
317 }
318 
319 /*
320  * Copy a string to a "safe" place
321  * (that is, to a buffer allocated by calloc).
322  */
323 	public char *
324 save(s)
325 	constant char *s;
326 {
327 	char *p;
328 
329 	p = (char *) ecalloc(strlen(s)+1, sizeof(char));
330 	strcpy(p, s);
331 	return (p);
332 }
333 
334 /*
335  * Allocate memory.
336  * Like calloc(), but never returns an error (NULL).
337  */
338 	public VOID_POINTER
339 ecalloc(count, size)
340 	int count;
341 	unsigned int size;
342 {
343 	VOID_POINTER p;
344 
345 	p = (VOID_POINTER) calloc(count, size);
346 	if (p != NULL)
347 		return (p);
348 	error("Cannot allocate memory", NULL_PARG);
349 	quit(QUIT_ERROR);
350 	/*NOTREACHED*/
351 	return (NULL);
352 }
353 
354 /*
355  * Skip leading spaces in a string.
356  */
357 	public char *
358 skipsp(s)
359 	char *s;
360 {
361 	while (*s == ' ' || *s == '\t')
362 		s++;
363 	return (s);
364 }
365 
366 /*
367  * See how many characters of two strings are identical.
368  * If uppercase is true, the first string must begin with an uppercase
369  * character; the remainder of the first string may be either case.
370  */
371 	public int
372 sprefix(ps, s, uppercase)
373 	char *ps;
374 	char *s;
375 	int uppercase;
376 {
377 	int c;
378 	int sc;
379 	int len = 0;
380 
381 	for ( ;  *s != '\0';  s++, ps++)
382 	{
383 		c = *ps;
384 		if (uppercase)
385 		{
386 			if (len == 0 && ASCII_IS_LOWER(c))
387 				return (-1);
388 			if (ASCII_IS_UPPER(c))
389 				c = ASCII_TO_LOWER(c);
390 		}
391 		sc = *s;
392 		if (len > 0 && ASCII_IS_UPPER(sc))
393 			sc = ASCII_TO_LOWER(sc);
394 		if (c != sc)
395 			break;
396 		len++;
397 	}
398 	return (len);
399 }
400 
401 /*
402  * Exit the program.
403  */
404 	public void
405 quit(status)
406 	int status;
407 {
408 	static int save_status;
409 
410 	/*
411 	 * Put cursor at bottom left corner, clear the line,
412 	 * reset the terminal modes, and exit.
413 	 */
414 	if (status < 0)
415 		status = save_status;
416 	else
417 		save_status = status;
418 #if LESSTEST
419 	rstat('Q');
420 #endif /*LESSTEST*/
421 	quitting = 1;
422 	if (interactive())
423 		clear_bot();
424 	deinit();
425 	flush();
426 	if (redraw_on_quit && term_init_done)
427 	{
428 		/*
429 		 * The last file text displayed might have been on an
430 		 * alternate screen, which now (since deinit) cannot be seen.
431 		 * redraw_on_quit tells us to redraw it on the main screen.
432 		 */
433 		first_time = 1; /* Don't print "skipping" or tildes */
434 		repaint();
435 		flush();
436 	}
437 	edit((char*)NULL);
438 	save_cmdhist();
439 	raw_mode(0);
440 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
441 	/*
442 	 * If we don't close 2, we get some garbage from
443 	 * 2's buffer when it flushes automatically.
444 	 * I cannot track this one down  RB
445 	 * The same bug shows up if we use ^C^C to abort.
446 	 */
447 	close(2);
448 #endif
449 #ifdef WIN32
450 	SetConsoleTitle(consoleTitle);
451 #endif
452 	close_getchr();
453 	exit(status);
454 }
455