1/* $FreeBSD$ */
2/*
3 * Copyright (C) 1984-2023  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
22public char *   every_first_cmd = NULL;
23public int      new_file;
24public int      is_tty;
25public IFILE    curr_ifile = NULL_IFILE;
26public IFILE    old_ifile = NULL_IFILE;
27public struct scrpos initial_scrpos;
28public POSITION start_attnpos = NULL_POSITION;
29public POSITION end_attnpos = NULL_POSITION;
30public int      wscroll;
31public char *   progname;
32public int      quitting;
33public int      secure;
34public int      dohelp;
35
36#if LOGFILE
37public int      logfile = -1;
38public int      force_logfile = FALSE;
39public char *   namelogfile = NULL;
40#endif
41
42#if EDITOR
43public char *   editor;
44public char *   editproto;
45#endif
46
47#if TAGS
48extern char *   tags;
49extern char *   tagoption;
50extern int      jump_sline;
51#endif
52
53#ifdef WIN32
54static char consoleTitle[256];
55#endif
56
57public int      one_screen;
58extern int      less_is_more;
59extern int      missing_cap;
60extern int      know_dumb;
61extern int      pr_type;
62extern int      quit_if_one_screen;
63extern int      no_init;
64extern int      errmsgs;
65extern int      redraw_on_quit;
66extern int      term_init_done;
67extern int      first_time;
68
69/*
70 * Entry point.
71 */
72int main(int argc, char *argv[])
73{
74	IFILE ifile;
75	char *s;
76
77#ifdef __EMX__
78	_response(&argc, &argv);
79	_wildcard(&argc, &argv);
80#endif
81
82	progname = *argv++;
83	argc--;
84
85#if SECURE
86	secure = 1;
87#else
88	secure = 0;
89	s = lgetenv("LESSSECURE");
90	if (!isnullenv(s))
91		secure = 1;
92#endif
93
94#ifdef WIN32
95	if (getenv("HOME") == NULL)
96	{
97		/*
98		 * If there is no HOME environment variable,
99		 * try the concatenation of HOMEDRIVE + HOMEPATH.
100		 */
101		char *drive = getenv("HOMEDRIVE");
102		char *path  = getenv("HOMEPATH");
103		if (drive != NULL && path != NULL)
104		{
105			char *env = (char *) ecalloc(strlen(drive) +
106					strlen(path) + 6, sizeof(char));
107			strcpy(env, "HOME=");
108			strcat(env, drive);
109			strcat(env, path);
110			putenv(env);
111		}
112	}
113	GetConsoleTitle(consoleTitle, sizeof(consoleTitle)/sizeof(char));
114#endif /* WIN32 */
115
116	/*
117	 * Process command line arguments and LESS environment arguments.
118	 * Command line arguments override environment arguments.
119	 */
120	is_tty = isatty(1);
121	init_mark();
122	init_cmds();
123	init_poll();
124	get_term();
125	init_charset();
126	init_line();
127	init_cmdhist();
128	init_option();
129	init_search();
130
131	/*
132	 * If the name of the executable program is "more",
133	 * act like LESS_IS_MORE is set.
134	 */
135	s = last_component(progname);
136	if (strcmp(s, "more") == 0)
137		less_is_more = 1;
138
139	init_prompt();
140
141	if (less_is_more)
142		scan_option("-fG");
143
144	s = lgetenv(less_is_more ? "MORE" : "LESS");
145	if (s != NULL)
146		scan_option(s);
147
148#define isoptstring(s)  less_is_more ? (((s)[0] == '-') && (s)[1] != '\0') : \
149			(((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
150	while (argc > 0 && (isoptstring(*argv) || isoptpending()))
151	{
152		s = *argv++;
153		argc--;
154		if (strcmp(s, "--") == 0)
155			break;
156		scan_option(s);
157	}
158#undef isoptstring
159
160	if (isoptpending())
161	{
162		/*
163		 * Last command line option was a flag requiring a
164		 * following string, but there was no following string.
165		 */
166		nopendopt();
167		quit(QUIT_OK);
168	}
169
170	if (less_is_more)
171		no_init = TRUE;
172
173	expand_cmd_tables();
174
175#if EDITOR
176	editor = lgetenv("VISUAL");
177	if (editor == NULL || *editor == '\0')
178	{
179		editor = lgetenv("EDITOR");
180		if (isnullenv(editor))
181			editor = EDIT_PGM;
182	}
183	editproto = lgetenv("LESSEDIT");
184	if (isnullenv(editproto))
185		editproto = "%E ?lm+%lm. %g";
186#endif
187
188	/*
189	 * Call get_ifile with all the command line filenames
190	 * to "register" them with the ifile system.
191	 */
192	ifile = NULL_IFILE;
193	if (dohelp)
194		ifile = get_ifile(FAKE_HELPFILE, ifile);
195	while (argc-- > 0)
196	{
197#if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
198		/*
199		 * Because the "shell" doesn't expand filename patterns,
200		 * treat each argument as a filename pattern rather than
201		 * a single filename.
202		 * Expand the pattern and iterate over the expanded list.
203		 */
204		struct textlist tlist;
205		char *filename;
206		char *gfilename;
207		char *qfilename;
208
209		gfilename = lglob(*argv++);
210		init_textlist(&tlist, gfilename);
211		filename = NULL;
212		while ((filename = forw_textlist(&tlist, filename)) != NULL)
213		{
214			qfilename = shell_unquote(filename);
215			(void) get_ifile(qfilename, ifile);
216			free(qfilename);
217			ifile = prev_ifile(NULL_IFILE);
218		}
219		free(gfilename);
220#else
221		(void) get_ifile(*argv++, ifile);
222		ifile = prev_ifile(NULL_IFILE);
223#endif
224	}
225	/*
226	 * Set up terminal, etc.
227	 */
228	if (!is_tty)
229	{
230		/*
231		 * Output is not a tty.
232		 * Just copy the input file(s) to output.
233		 */
234		set_output(1); /* write to stdout */
235		SET_BINARY(1);
236		if (edit_first() == 0)
237		{
238			do {
239				cat_file();
240			} while (edit_next(1) == 0);
241		}
242		quit(QUIT_OK);
243	}
244
245	if (missing_cap && !know_dumb && !less_is_more)
246		error("WARNING: terminal is not fully functional", NULL_PARG);
247	open_getchr();
248	raw_mode(1);
249	init_signals(1);
250
251	/*
252	 * Select the first file to examine.
253	 */
254#if TAGS
255	if (tagoption != NULL || strcmp(tags, "-") == 0)
256	{
257		/*
258		 * A -t option was given.
259		 * Verify that no filenames were also given.
260		 * Edit the file selected by the "tags" search,
261		 * and search for the proper line in the file.
262		 */
263		if (nifile() > 0)
264		{
265			error("No filenames allowed with -t option", NULL_PARG);
266			quit(QUIT_ERROR);
267		}
268		findtag(tagoption);
269		if (edit_tagfile())  /* Edit file which contains the tag */
270			quit(QUIT_ERROR);
271		/*
272		 * Search for the line which contains the tag.
273		 * Set up initial_scrpos so we display that line.
274		 */
275		initial_scrpos.pos = tagsearch();
276		if (initial_scrpos.pos == NULL_POSITION)
277			quit(QUIT_ERROR);
278		initial_scrpos.ln = jump_sline;
279	} else
280#endif
281	{
282		if (edit_first())
283			quit(QUIT_ERROR);
284		/*
285		 * See if file fits on one screen to decide whether
286		 * to send terminal init. But don't need this
287		 * if -X (no_init) overrides this (see init()).
288		 */
289		if (quit_if_one_screen)
290		{
291			if (nifile() > 1) /* If more than one file, -F cannot be used */
292				quit_if_one_screen = FALSE;
293			else if (!no_init)
294				one_screen = get_one_screen();
295		}
296	}
297
298	if (errmsgs > 0)
299	{
300		/*
301		 * We displayed some messages on error output
302		 * (file descriptor 2; see flush()).
303		 * Before erasing the screen contents, wait for a keystroke.
304		 */
305		less_printf("Press RETURN to continue ", NULL_PARG);
306		get_return();
307		putchr('\n');
308	}
309	set_output(1);
310	init();
311	commands();
312	quit(QUIT_OK);
313	/*NOTREACHED*/
314	return (0);
315}
316
317/*
318 * Copy a string to a "safe" place
319 * (that is, to a buffer allocated by calloc).
320 */
321public char * save(constant char *s)
322{
323	char *p;
324
325	p = (char *) ecalloc(strlen(s)+1, sizeof(char));
326	strcpy(p, s);
327	return (p);
328}
329
330public void out_of_memory(void)
331{
332	error("Cannot allocate memory", NULL_PARG);
333	quit(QUIT_ERROR);
334}
335
336/*
337 * Allocate memory.
338 * Like calloc(), but never returns an error (NULL).
339 */
340public void * ecalloc(int count, unsigned int size)
341{
342	void * p;
343
344	p = (void *) calloc(count, size);
345	if (p == NULL)
346		out_of_memory();
347	return p;
348}
349
350/*
351 * Skip leading spaces in a string.
352 */
353public char * skipsp(char *s)
354{
355	while (*s == ' ' || *s == '\t')
356		s++;
357	return (s);
358}
359
360/*
361 * See how many characters of two strings are identical.
362 * If uppercase is true, the first string must begin with an uppercase
363 * character; the remainder of the first string may be either case.
364 */
365public int sprefix(char *ps, char *s, int uppercase)
366{
367	int c;
368	int sc;
369	int len = 0;
370
371	for ( ;  *s != '\0';  s++, ps++)
372	{
373		c = *ps;
374		if (uppercase)
375		{
376			if (len == 0 && ASCII_IS_LOWER(c))
377				return (-1);
378			if (ASCII_IS_UPPER(c))
379				c = ASCII_TO_LOWER(c);
380		}
381		sc = *s;
382		if (len > 0 && ASCII_IS_UPPER(sc))
383			sc = ASCII_TO_LOWER(sc);
384		if (c != sc)
385			break;
386		len++;
387	}
388	return (len);
389}
390
391/*
392 * Exit the program.
393 */
394public void quit(int status)
395{
396	static int save_status;
397
398	/*
399	 * Put cursor at bottom left corner, clear the line,
400	 * reset the terminal modes, and exit.
401	 */
402	if (status < 0)
403		status = save_status;
404	else
405		save_status = status;
406	quitting = 1;
407	check_altpipe_error();
408	if (interactive())
409		clear_bot();
410	deinit();
411	flush();
412	if (redraw_on_quit && term_init_done)
413	{
414		/*
415		 * The last file text displayed might have been on an
416		 * alternate screen, which now (since deinit) cannot be seen.
417		 * redraw_on_quit tells us to redraw it on the main screen.
418		 */
419		first_time = 1; /* Don't print "skipping" or tildes */
420		repaint();
421		flush();
422	}
423	edit((char*)NULL);
424	save_cmdhist();
425	raw_mode(0);
426#if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
427	/*
428	 * If we don't close 2, we get some garbage from
429	 * 2's buffer when it flushes automatically.
430	 * I cannot track this one down  RB
431	 * The same bug shows up if we use ^C^C to abort.
432	 */
433	close(2);
434#endif
435#ifdef WIN32
436	SetConsoleTitle(consoleTitle);
437#endif
438	close_getchr();
439	exit(status);
440}
441