xref: /freebsd/contrib/less/main.c (revision c3c73b4f0a91d2806e1a632b75f769fb4fa89576)
1 /* $FreeBSD$ */
2 /*
3  * Copyright (C) 1984-2020  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 int	any_display = FALSE;
29 public POSITION	start_attnpos = NULL_POSITION;
30 public POSITION	end_attnpos = NULL_POSITION;
31 public int	wscroll;
32 public char *	progname;
33 public int	quitting;
34 public int	secure;
35 public int	dohelp;
36 
37 #if LOGFILE
38 public int	logfile = -1;
39 public int	force_logfile = FALSE;
40 public char *	namelogfile = NULL;
41 #endif
42 
43 #if EDITOR
44 public char *	editor;
45 public char *	editproto;
46 #endif
47 
48 #if TAGS
49 extern char *	tags;
50 extern char *	tagoption;
51 extern int	jump_sline;
52 #endif
53 
54 #ifdef WIN32
55 static char consoleTitle[256];
56 #endif
57 
58 public int	one_screen;
59 extern int	less_is_more;
60 extern int	missing_cap;
61 extern int	know_dumb;
62 extern int	no_init;
63 extern int	pr_type;
64 extern int	quit_if_one_screen;
65 extern int	no_init;
66 
67 
68 /*
69  * Entry point.
70  */
71 int
72 main(argc, argv)
73 	int argc;
74 	char *argv[];
75 {
76 	IFILE ifile;
77 	char *s;
78 
79 #ifdef __EMX__
80 	_response(&argc, &argv);
81 	_wildcard(&argc, &argv);
82 #endif
83 
84 	progname = *argv++;
85 	argc--;
86 
87 	secure = 0;
88 	s = lgetenv("LESSSECURE");
89 	if (!isnullenv(s))
90 		secure = 1;
91 
92 #ifdef WIN32
93 	if (getenv("HOME") == NULL)
94 	{
95 		/*
96 		 * If there is no HOME environment variable,
97 		 * try the concatenation of HOMEDRIVE + HOMEPATH.
98 		 */
99 		char *drive = getenv("HOMEDRIVE");
100 		char *path  = getenv("HOMEPATH");
101 		if (drive != NULL && path != NULL)
102 		{
103 			char *env = (char *) ecalloc(strlen(drive) +
104 					strlen(path) + 6, sizeof(char));
105 			strcpy(env, "HOME=");
106 			strcat(env, drive);
107 			strcat(env, path);
108 			putenv(env);
109 		}
110 	}
111 	GetConsoleTitle(consoleTitle, sizeof(consoleTitle)/sizeof(char));
112 #endif /* WIN32 */
113 
114 	/*
115 	 * Process command line arguments and LESS environment arguments.
116 	 * Command line arguments override environment arguments.
117 	 */
118 	is_tty = isatty(1);
119 	init_mark();
120 	init_cmds();
121 	get_term();
122 	init_charset();
123 	init_line();
124 	init_cmdhist();
125 	init_option();
126 	init_search();
127 
128 	/*
129 	 * If the name of the executable program is "more",
130 	 * act like LESS_IS_MORE is set.
131 	 */
132 	s = last_component(progname);
133 	if (strcmp(s, "more") == 0)
134 		less_is_more = 1;
135 
136 	init_prompt();
137 
138 	if (less_is_more)
139 		scan_option("-fG");
140 
141 	s = lgetenv(less_is_more ? "MORE" : "LESS");
142 	if (s != NULL)
143 		scan_option(save(s));
144 
145 #define	isoptstring(s)	less_is_more   ? (((s)[0] == '-') && (s)[1] != '\0') : \
146 			(((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
147 	while (argc > 0 && (isoptstring(*argv) || isoptpending()))
148 	{
149 		s = *argv++;
150 		argc--;
151 		if (strcmp(s, "--") == 0)
152 			break;
153 		scan_option(s);
154 	}
155 #undef isoptstring
156 
157 	if (isoptpending())
158 	{
159 		/*
160 		 * Last command line option was a flag requiring a
161 		 * following string, but there was no following string.
162 		 */
163 		nopendopt();
164 		quit(QUIT_OK);
165 	}
166 
167 	if (less_is_more)
168 		no_init = TRUE;
169 
170 	expand_cmd_tables();
171 
172 #if EDITOR
173 	editor = lgetenv("VISUAL");
174 	if (editor == NULL || *editor == '\0')
175 	{
176 		editor = lgetenv("EDITOR");
177 		if (isnullenv(editor))
178 			editor = EDIT_PGM;
179 	}
180 	editproto = lgetenv("LESSEDIT");
181 	if (isnullenv(editproto))
182 		editproto = "%E ?lm+%lm. %g";
183 #endif
184 
185 	/*
186 	 * Call get_ifile with all the command line filenames
187 	 * to "register" them with the ifile system.
188 	 */
189 	ifile = NULL_IFILE;
190 	if (dohelp)
191 		ifile = get_ifile(FAKE_HELPFILE, ifile);
192 	while (argc-- > 0)
193 	{
194 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
195 		/*
196 		 * Because the "shell" doesn't expand filename patterns,
197 		 * treat each argument as a filename pattern rather than
198 		 * a single filename.
199 		 * Expand the pattern and iterate over the expanded list.
200 		 */
201 		struct textlist tlist;
202 		char *filename;
203 		char *gfilename;
204 		char *qfilename;
205 
206 		gfilename = lglob(*argv++);
207 		init_textlist(&tlist, gfilename);
208 		filename = NULL;
209 		while ((filename = forw_textlist(&tlist, filename)) != NULL)
210 		{
211 			qfilename = shell_unquote(filename);
212 			(void) get_ifile(qfilename, ifile);
213 			free(qfilename);
214 			ifile = prev_ifile(NULL_IFILE);
215 		}
216 		free(gfilename);
217 #else
218 		(void) get_ifile(*argv++, ifile);
219 		ifile = prev_ifile(NULL_IFILE);
220 #endif
221 	}
222 	/*
223 	 * Set up terminal, etc.
224 	 */
225 	if (!is_tty)
226 	{
227 		/*
228 		 * Output is not a tty.
229 		 * Just copy the input file(s) to output.
230 		 */
231 		SET_BINARY(1);
232 		if (edit_first() == 0)
233 		{
234 			do {
235 				cat_file();
236 			} while (edit_next(1) == 0);
237 		}
238 		quit(QUIT_OK);
239 	}
240 
241 	if (missing_cap && !know_dumb && !less_is_more)
242 		error("WARNING: terminal is not fully functional", NULL_PARG);
243 	open_getchr();
244 	raw_mode(1);
245 	init_signals(1);
246 
247 	/*
248 	 * Select the first file to examine.
249 	 */
250 #if TAGS
251 	if (tagoption != NULL || strcmp(tags, "-") == 0)
252 	{
253 		/*
254 		 * A -t option was given.
255 		 * Verify that no filenames were also given.
256 		 * Edit the file selected by the "tags" search,
257 		 * and search for the proper line in the file.
258 		 */
259 		if (nifile() > 0)
260 		{
261 			error("No filenames allowed with -t option", NULL_PARG);
262 			quit(QUIT_ERROR);
263 		}
264 		findtag(tagoption);
265 		if (edit_tagfile())  /* Edit file which contains the tag */
266 			quit(QUIT_ERROR);
267 		/*
268 		 * Search for the line which contains the tag.
269 		 * Set up initial_scrpos so we display that line.
270 		 */
271 		initial_scrpos.pos = tagsearch();
272 		if (initial_scrpos.pos == NULL_POSITION)
273 			quit(QUIT_ERROR);
274 		initial_scrpos.ln = jump_sline;
275 	} else
276 #endif
277 	{
278 		if (edit_first())
279 			quit(QUIT_ERROR);
280 		/*
281 		 * See if file fits on one screen to decide whether
282 		 * to send terminal init. But don't need this
283 		 * if -X (no_init) overrides this (see init()).
284 		 */
285 		if (quit_if_one_screen)
286 		{
287 			if (nifile() > 1) /* If more than one file, -F cannot be used */
288 				quit_if_one_screen = FALSE;
289 			else if (!no_init)
290 				one_screen = get_one_screen();
291 		}
292 	}
293 
294 	init();
295 	commands();
296 	quit(QUIT_OK);
297 	/*NOTREACHED*/
298 	return (0);
299 }
300 
301 /*
302  * Copy a string to a "safe" place
303  * (that is, to a buffer allocated by calloc).
304  */
305 	public char *
306 save(s)
307 	constant char *s;
308 {
309 	char *p;
310 
311 	p = (char *) ecalloc(strlen(s)+1, sizeof(char));
312 	strcpy(p, s);
313 	return (p);
314 }
315 
316 /*
317  * Allocate memory.
318  * Like calloc(), but never returns an error (NULL).
319  */
320 	public VOID_POINTER
321 ecalloc(count, size)
322 	int count;
323 	unsigned int size;
324 {
325 	VOID_POINTER p;
326 
327 	p = (VOID_POINTER) calloc(count, size);
328 	if (p != NULL)
329 		return (p);
330 	error("Cannot allocate memory", NULL_PARG);
331 	quit(QUIT_ERROR);
332 	/*NOTREACHED*/
333 	return (NULL);
334 }
335 
336 /*
337  * Skip leading spaces in a string.
338  */
339 	public char *
340 skipsp(s)
341 	char *s;
342 {
343 	while (*s == ' ' || *s == '\t')
344 		s++;
345 	return (s);
346 }
347 
348 /*
349  * See how many characters of two strings are identical.
350  * If uppercase is true, the first string must begin with an uppercase
351  * character; the remainder of the first string may be either case.
352  */
353 	public int
354 sprefix(ps, s, uppercase)
355 	char *ps;
356 	char *s;
357 	int uppercase;
358 {
359 	int c;
360 	int sc;
361 	int len = 0;
362 
363 	for ( ;  *s != '\0';  s++, ps++)
364 	{
365 		c = *ps;
366 		if (uppercase)
367 		{
368 			if (len == 0 && ASCII_IS_LOWER(c))
369 				return (-1);
370 			if (ASCII_IS_UPPER(c))
371 				c = ASCII_TO_LOWER(c);
372 		}
373 		sc = *s;
374 		if (len > 0 && ASCII_IS_UPPER(sc))
375 			sc = ASCII_TO_LOWER(sc);
376 		if (c != sc)
377 			break;
378 		len++;
379 	}
380 	return (len);
381 }
382 
383 /*
384  * Exit the program.
385  */
386 	public void
387 quit(status)
388 	int status;
389 {
390 	static int save_status;
391 
392 	/*
393 	 * Put cursor at bottom left corner, clear the line,
394 	 * reset the terminal modes, and exit.
395 	 */
396 	if (status < 0)
397 		status = save_status;
398 	else
399 		save_status = status;
400 	quitting = 1;
401 	edit((char*)NULL);
402 	save_cmdhist();
403 	if (any_display && is_tty)
404 		clear_bot();
405 	deinit();
406 	flush();
407 	raw_mode(0);
408 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
409 	/*
410 	 * If we don't close 2, we get some garbage from
411 	 * 2's buffer when it flushes automatically.
412 	 * I cannot track this one down  RB
413 	 * The same bug shows up if we use ^C^C to abort.
414 	 */
415 	close(2);
416 #endif
417 #ifdef WIN32
418 	SetConsoleTitle(consoleTitle);
419 #endif
420 	close_getchr();
421 	exit(status);
422 }
423