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
edit(filename)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
next_file(n)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
prev_file(n)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
cat_file()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
main(argc,argv)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 *
save(s)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
quit()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