1/*	$NetBSD: main.c,v 1.12 2013/07/03 14:29:28 matt Exp $	*/
2
3/*
4 * Copyright (c) 1988 Mark Nudelman
5 * Copyright (c) 1988, 1993
6 *	Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34#ifndef lint
35__COPYRIGHT("@(#) Copyright (c) 1988 Mark Nudelman.");
36__COPYRIGHT("@(#) Copyright (c) 1988, 1993 "
37"Regents of the University of California.  All rights reserved.");
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/7/93";
43#else
44__RCSID("$NetBSD: main.c,v 1.12 2013/07/03 14:29:28 matt Exp $");
45#endif
46#endif /* not lint */
47
48/*
49 * Entry point, initialization, miscellaneous routines.
50 */
51
52#include <sys/types.h>
53#include <sys/file.h>
54#include <stdio.h>
55#include <string.h>
56#include <errno.h>
57#include <stdlib.h>
58#include <unistd.h>
59
60#include "less.h"
61#include "extern.h"
62
63int	ispipe;
64int	new_file;
65int	is_tty;
66char	*current_file, *previous_file, *current_name, *next_name;
67off_t	prev_pos;
68int	any_display;
69int	scroll_lines;
70int	ac;
71char	**av;
72int	curr_ac;
73int	quitting;
74
75static void cat_file __P((void));
76/*
77 * Edit a new file.
78 * Filename "-" means standard input.
79 * No filename means the "current" file, from the command line.
80 */
81int
82edit(filename)
83	char *filename;
84{
85	int f;
86	char *m;
87	off_t initial_pos;
88	static int didpipe;
89	char message[100], *p;
90
91	initial_pos = NULL_POSITION;
92	if (filename == NULL || *filename == '\0') {
93		if (curr_ac >= ac) {
94			error("No current file");
95			return(0);
96		}
97		filename = save(av[curr_ac]);
98	}
99	else if (strcmp(filename, "#") == 0) {
100		if (*previous_file == '\0') {
101			error("no previous file");
102			return(0);
103		}
104		filename = save(previous_file);
105		initial_pos = prev_pos;
106	} else
107		filename = save(filename);
108
109	/* use standard input. */
110	if (!strcmp(filename, "-")) {
111		if (didpipe) {
112			error("Can view standard input only once");
113			return(0);
114		}
115		f = 0;
116	}
117	else if ((m = bad_file(filename, message, sizeof(message))) != NULL) {
118		error(m);
119		free(filename);
120		return(0);
121	}
122	else if ((f = open(filename, O_RDONLY, 0)) < 0) {
123		(void)snprintf(message, sizeof(message), "%s: %s", filename,
124		    strerror(errno));
125		error(message);
126		free(filename);
127		return(0);
128	}
129
130	if (isatty(f)) {
131		/*
132		 * Not really necessary to call this an error,
133		 * but if the control terminal (for commands)
134		 * and the input file (for data) are the same,
135		 * we get weird results at best.
136		 */
137		error("Can't take input from a terminal");
138		if (f > 0)
139			(void)close(f);
140		(void)free(filename);
141		return(0);
142	}
143
144	/*
145	 * We are now committed to using the new file.
146	 * Close the current input file and set up to use the new one.
147	 */
148	if (file > 0)
149		(void)close(file);
150	new_file = 1;
151	if (previous_file != NULL)
152		free(previous_file);
153	previous_file = current_file;
154	current_file = filename;
155	pos_clear();
156	prev_pos = position(TOP);
157	ispipe = (f == 0);
158	if (ispipe) {
159		didpipe = 1;
160		current_name = "stdin";
161	} else
162		current_name = (p = rindex(filename, '/')) ? p + 1 : filename;
163	if (curr_ac >= ac)
164		next_name = NULL;
165	else
166		next_name = av[curr_ac + 1];
167	file = f;
168	ch_init(cbufs, 0);
169	init_mark();
170
171	if (is_tty) {
172		int no_display = !any_display;
173		any_display = 1;
174		if (no_display && errmsgs > 0) {
175			/*
176			 * We displayed some messages on error output
177			 * (file descriptor 2; see error() function).
178			 * Before erasing the screen contents,
179			 * display the file name and wait for a keystroke.
180			 */
181			error(filename);
182		}
183		/*
184		 * Indicate there is nothing displayed yet.
185		 */
186		if (initial_pos != NULL_POSITION)
187			jump_loc(initial_pos);
188		clr_linenum();
189	}
190	return(1);
191}
192
193/*
194 * Edit the next file in the command line list.
195 */
196void
197next_file(n)
198	int n;
199{
200	if (curr_ac + n >= ac) {
201		if (quit_at_eof || position(TOP) == NULL_POSITION)
202			quit();
203		error("No (N-th) next file");
204	}
205	else
206		(void)edit(av[curr_ac += n]);
207}
208
209/*
210 * Edit the previous file in the command line list.
211 */
212void
213prev_file(n)
214	int n;
215{
216	if (curr_ac - n < 0)
217		error("No (N-th) previous file");
218	else
219		(void)edit(av[curr_ac -= n]);
220}
221
222/*
223 * copy a file directly to standard output; used if stdout is not a tty.
224 * the only processing is to squeeze multiple blank input lines.
225 */
226static void
227cat_file()
228{
229	int c, empty;
230
231	if (squeeze) {
232		empty = 0;
233		while ((c = ch_forw_get()) != EOI)
234			if (c != '\n') {
235				putchr(c);
236				empty = 0;
237			}
238			else if (empty < 2) {
239				putchr(c);
240				++empty;
241			}
242	}
243	else while ((c = ch_forw_get()) != EOI)
244		putchr(c);
245	flush();
246}
247
248int
249main(argc, argv)
250	int argc;
251	char **argv;
252{
253	int envargc, argcnt;
254	char *envargv[3];
255
256	/*
257	 * Process command line arguments and MORE environment arguments.
258	 * Command line arguments override environment arguments.
259	 */
260	if ((envargv[1] = getenv("MORE")) != NULL) {
261		envargc = 2;
262		envargv[0] = "more";
263		envargv[2] = NULL;
264		(void)option(envargc, envargv);
265	}
266	argcnt = option(argc, argv);
267	argv += argcnt;
268	argc -= argcnt;
269
270	/*
271	 * Set up list of files to be examined.
272	 */
273	ac = argc;
274	av = argv;
275	curr_ac = 0;
276
277	/*
278	 * Set up terminal, etc.
279	 */
280	is_tty = isatty(1);
281	if (!is_tty) {
282		/*
283		 * Output is not a tty.
284		 * Just copy the input file(s) to output.
285		 */
286		if (ac < 1) {
287			(void)edit("-");
288			cat_file();
289		} else {
290			do {
291				(void)edit((char *)NULL);
292				if (file >= 0)
293					cat_file();
294			} while (++curr_ac < ac);
295		}
296		exit(0);
297	}
298
299	raw_mode(1);
300	get_term();
301	open_getchr();
302	init();
303	init_signals(1);
304
305	/* select the first file to examine. */
306	if (ac < 1)
307		(void)edit("-");	/* Standard input */
308	else {
309		/*
310		 * Try all the files named as command arguments.
311		 * We are simply looking for one which can be
312		 * opened without error.
313		 */
314		do {
315			(void)edit((char *)NULL);
316		} while (file < 0 && ++curr_ac < ac);
317	}
318
319	if (file >= 0)
320		commands();
321	quit();
322}
323
324/*
325 * Copy a string to a "safe" place
326 * (that is, to a buffer allocated by malloc).
327 */
328char *
329save(s)
330	char *s;
331{
332	char *p;
333
334	p = strdup(s);
335	if (p == NULL)
336	{
337		error("cannot allocate memory");
338		quit();
339	}
340	return(p);
341}
342
343/*
344 * Exit the program.
345 */
346void
347quit()
348{
349	/*
350	 * Put cursor at bottom left corner, clear the line,
351	 * reset the terminal modes, and exit.
352	 */
353	quitting = 1;
354	lower_left();
355	clear_eol();
356	deinit();
357	flush();
358	raw_mode(0);
359	exit(0);
360}
361