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      1 /*	$NetBSD: main.c,v 1.13 2013/07/10 08:00:29 joerg 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
     42 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/7/93";
     43 #else
     44 __RCSID("$NetBSD: main.c,v 1.13 2013/07/10 08:00:29 joerg 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 
     63 int	ispipe;
     64 int	new_file;
     65 int	is_tty;
     66 char	*current_file, *previous_file, *current_name, *next_name;
     67 off_t	prev_pos;
     68 int	any_display;
     69 int	scroll_lines;
     70 int	ac;
     71 char	**av;
     72 int	curr_ac;
     73 int	quitting;
     74 
     75 static 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  */
     81 int
     82 edit(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  */
    196 void
    197 next_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  */
    212 void
    213 prev_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  */
    226 static void
    227 cat_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 
    248 int
    249 main(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  */
    328 char *
    329 save(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  */
    346 void
    347 quit()
    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