1/*	$NetBSD: main.c,v 1.9 2004/09/01 01:46:56 chs 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(\
36"@(#) Copyright (c) 1988 Mark Nudelman.\
37@(#) Copyright (c) 1988, 1993\
38Regents of the University of California.  All rights reserved.");
39#endif /* not lint */
40
41#ifndef lint
42#if 0
43static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/7/93";
44#else
45__RCSID("$NetBSD: main.c,v 1.9 2004/09/01 01:46:56 chs Exp $");
46#endif
47#endif /* not lint */
48
49/*
50 * Entry point, initialization, miscellaneous routines.
51 */
52
53#include <sys/types.h>
54#include <sys/file.h>
55#include <stdio.h>
56#include <string.h>
57#include <errno.h>
58#include <stdlib.h>
59#include <unistd.h>
60
61#include "less.h"
62#include "extern.h"
63
64int	ispipe;
65int	new_file;
66int	is_tty;
67char	*current_file, *previous_file, *current_name, *next_name;
68off_t	prev_pos;
69int	any_display;
70int	scroll_lines;
71int	ac;
72char	**av;
73int	curr_ac;
74int	quitting;
75
76static void cat_file __P((void));
77/*
78 * Edit a new file.
79 * Filename "-" means standard input.
80 * No filename means the "current" file, from the command line.
81 */
82int
83edit(filename)
84	char *filename;
85{
86	int f;
87	char *m;
88	off_t initial_pos;
89	static int didpipe;
90	char message[100], *p;
91
92	initial_pos = NULL_POSITION;
93	if (filename == NULL || *filename == '\0') {
94		if (curr_ac >= ac) {
95			error("No current file");
96			return(0);
97		}
98		filename = save(av[curr_ac]);
99	}
100	else if (strcmp(filename, "#") == 0) {
101		if (*previous_file == '\0') {
102			error("no previous file");
103			return(0);
104		}
105		filename = save(previous_file);
106		initial_pos = prev_pos;
107	} else
108		filename = save(filename);
109
110	/* use standard input. */
111	if (!strcmp(filename, "-")) {
112		if (didpipe) {
113			error("Can view standard input only once");
114			return(0);
115		}
116		f = 0;
117	}
118	else if ((m = bad_file(filename, message, sizeof(message))) != NULL) {
119		error(m);
120		free(filename);
121		return(0);
122	}
123	else if ((f = open(filename, O_RDONLY, 0)) < 0) {
124		(void)snprintf(message, sizeof(message), "%s: %s", filename,
125		    strerror(errno));
126		error(message);
127		free(filename);
128		return(0);
129	}
130
131	if (isatty(f)) {
132		/*
133		 * Not really necessary to call this an error,
134		 * but if the control terminal (for commands)
135		 * and the input file (for data) are the same,
136		 * we get weird results at best.
137		 */
138		error("Can't take input from a terminal");
139		if (f > 0)
140			(void)close(f);
141		(void)free(filename);
142		return(0);
143	}
144
145	/*
146	 * We are now committed to using the new file.
147	 * Close the current input file and set up to use the new one.
148	 */
149	if (file > 0)
150		(void)close(file);
151	new_file = 1;
152	if (previous_file != NULL)
153		free(previous_file);
154	previous_file = current_file;
155	current_file = filename;
156	pos_clear();
157	prev_pos = position(TOP);
158	ispipe = (f == 0);
159	if (ispipe) {
160		didpipe = 1;
161		current_name = "stdin";
162	} else
163		current_name = (p = rindex(filename, '/')) ? p + 1 : filename;
164	if (curr_ac >= ac)
165		next_name = NULL;
166	else
167		next_name = av[curr_ac + 1];
168	file = f;
169	ch_init(cbufs, 0);
170	init_mark();
171
172	if (is_tty) {
173		int no_display = !any_display;
174		any_display = 1;
175		if (no_display && errmsgs > 0) {
176			/*
177			 * We displayed some messages on error output
178			 * (file descriptor 2; see error() function).
179			 * Before erasing the screen contents,
180			 * display the file name and wait for a keystroke.
181			 */
182			error(filename);
183		}
184		/*
185		 * Indicate there is nothing displayed yet.
186		 */
187		if (initial_pos != NULL_POSITION)
188			jump_loc(initial_pos);
189		clr_linenum();
190	}
191	return(1);
192}
193
194/*
195 * Edit the next file in the command line list.
196 */
197void
198next_file(n)
199	int n;
200{
201	if (curr_ac + n >= ac) {
202		if (quit_at_eof || position(TOP) == NULL_POSITION)
203			quit();
204		error("No (N-th) next file");
205	}
206	else
207		(void)edit(av[curr_ac += n]);
208}
209
210/*
211 * Edit the previous file in the command line list.
212 */
213void
214prev_file(n)
215	int n;
216{
217	if (curr_ac - n < 0)
218		error("No (N-th) previous file");
219	else
220		(void)edit(av[curr_ac -= n]);
221}
222
223/*
224 * copy a file directly to standard output; used if stdout is not a tty.
225 * the only processing is to squeeze multiple blank input lines.
226 */
227static void
228cat_file()
229{
230	int c, empty;
231
232	if (squeeze) {
233		empty = 0;
234		while ((c = ch_forw_get()) != EOI)
235			if (c != '\n') {
236				putchr(c);
237				empty = 0;
238			}
239			else if (empty < 2) {
240				putchr(c);
241				++empty;
242			}
243	}
244	else while ((c = ch_forw_get()) != EOI)
245		putchr(c);
246	flush();
247}
248
249int
250main(argc, argv)
251	int argc;
252	char **argv;
253{
254	int envargc, argcnt;
255	char *envargv[2];
256
257	/*
258	 * Process command line arguments and MORE environment arguments.
259	 * Command line arguments override environment arguments.
260	 */
261	if ((envargv[1] = getenv("MORE")) != NULL) {
262		envargc = 2;
263		envargv[0] = "more";
264		envargv[2] = NULL;
265		(void)option(envargc, envargv);
266	}
267	argcnt = option(argc, argv);
268	argv += argcnt;
269	argc -= argcnt;
270
271	/*
272	 * Set up list of files to be examined.
273	 */
274	ac = argc;
275	av = argv;
276	curr_ac = 0;
277
278	/*
279	 * Set up terminal, etc.
280	 */
281	is_tty = isatty(1);
282	if (!is_tty) {
283		/*
284		 * Output is not a tty.
285		 * Just copy the input file(s) to output.
286		 */
287		if (ac < 1) {
288			(void)edit("-");
289			cat_file();
290		} else {
291			do {
292				(void)edit((char *)NULL);
293				if (file >= 0)
294					cat_file();
295			} while (++curr_ac < ac);
296		}
297		exit(0);
298	}
299
300	raw_mode(1);
301	get_term();
302	open_getchr();
303	init();
304	init_signals(1);
305
306	/* select the first file to examine. */
307	if (ac < 1)
308		(void)edit("-");	/* Standard input */
309	else {
310		/*
311		 * Try all the files named as command arguments.
312		 * We are simply looking for one which can be
313		 * opened without error.
314		 */
315		do {
316			(void)edit((char *)NULL);
317		} while (file < 0 && ++curr_ac < ac);
318	}
319
320	if (file >= 0)
321		commands();
322	quit();
323}
324
325/*
326 * Copy a string to a "safe" place
327 * (that is, to a buffer allocated by malloc).
328 */
329char *
330save(s)
331	char *s;
332{
333	char *p;
334
335	p = strdup(s);
336	if (p == NULL)
337	{
338		error("cannot allocate memory");
339		quit();
340	}
341	return(p);
342}
343
344/*
345 * Exit the program.
346 */
347void
348quit()
349{
350	/*
351	 * Put cursor at bottom left corner, clear the line,
352	 * reset the terminal modes, and exit.
353	 */
354	quitting = 1;
355	lower_left();
356	clear_eol();
357	deinit();
358	flush();
359	raw_mode(0);
360	exit(0);
361}
362