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1 /****************************************************************************
2  * Copyright 2019-2021,2022 Thomas E. Dickey                                *
3  * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
4  *                                                                          *
5  * Permission is hereby granted, free of charge, to any person obtaining a  *
6  * copy of this software and associated documentation files (the            *
7  * "Software"), to deal in the Software without restriction, including      *
8  * without limitation the rights to use, copy, modify, merge, publish,      *
9  * distribute, distribute with modifications, sublicense, and/or sell       *
10  * copies of the Software, and to permit persons to whom the Software is    *
11  * furnished to do so, subject to the following conditions:                 *
12  *                                                                          *
13  * The above copyright notice and this permission notice shall be included  *
14  * in all copies or substantial portions of the Software.                   *
15  *                                                                          *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23  *                                                                          *
24  * Except as contained in this notice, the name(s) of the above copyright   *
25  * holders shall not be used in advertising or otherwise to promote the     *
26  * sale, use or other dealings in this Software without prior written       *
27  * authorization.                                                           *
28  ****************************************************************************/
29 /*
30  * view.c -- a silly little viewer program
31  *
32  * written by Eric S. Raymond <esr@snark.thyrsus.com> December 1994
33  * to test the scrolling code in ncurses.
34  *
35  * modified by Thomas Dickey <dickey@clark.net> July 1995 to demonstrate
36  * the use of 'resizeterm()', and May 2000 to illustrate wide-character
37  * handling.  This program intentionally does not use pads, to allow testing
38  * with less-capable implementations of curses.
39  *
40  * Takes a filename argument.  It's a simple file-viewer with various
41  * scroll-up and scroll-down commands.
42  *
43  * n	-- scroll one line forward
44  * p	-- scroll one line back
45  *
46  * Either command accepts a numeric prefix interpreted as a repeat count.
47  * Thus, typing `5n' should scroll forward 5 lines in the file.
48  *
49  * The way you can tell this is working OK is that, in the trace file,
50  * there should be one scroll operation plus a small number of line
51  * updates, as opposed to a whole-page update.  This means the physical
52  * scroll operation worked, and the refresh() code only had to do a
53  * partial repaint.
54  *
55  * $Id: view.c,v 1.145 2022/12/04 00:40:11 tom Exp $
56  */
57 
58 #include <test.priv.h>
59 #include <widechars.h>
60 #include <popup_msg.h>
61 
62 #include <sys/stat.h>
63 #include <time.h>
64 
65 static GCC_NORETURN void finish(int sig);
66 
67 #define my_pair 1
68 
69 static int shift = 0;
70 static bool try_color = FALSE;
71 
72 static char *fname;
73 static NCURSES_CH_T **vec_lines;
74 static NCURSES_CH_T **lptr;
75 static int num_lines;
76 
77 #if USE_WIDEC_SUPPORT
78 static bool n_option = FALSE;
79 #endif
80 
81 static GCC_NORETURN void
failed(const char * msg)82 failed(const char *msg)
83 {
84     endwin();
85     fprintf(stderr, "%s\n", msg);
86     ExitProgram(EXIT_FAILURE);
87 }
88 
89 static int
ch_len(NCURSES_CH_T * src)90 ch_len(NCURSES_CH_T *src)
91 {
92     int result = 0;
93 
94 #if USE_WIDEC_SUPPORT
95     for (;;) {
96 	int count;
97 	TEST_CCHAR(src, count, {
98 	    int len = wcwidth(test_wch[0]);
99 	    result += (len > 0) ? len : 1;
100 	    ++src;
101 	}
102 	, {
103 	    break;
104 	})
105     }
106 #else
107     while (*src++)
108 	result++;
109 #endif
110     return result;
111 }
112 
113 static void
finish(int sig)114 finish(int sig)
115 {
116     endwin();
117 #if NO_LEAKS
118     if (vec_lines != 0) {
119 	int n;
120 	for (n = 0; n < num_lines; ++n) {
121 	    free(vec_lines[n]);
122 	}
123 	free(vec_lines);
124     }
125 #endif
126     ExitProgram(sig != 0 ? EXIT_FAILURE : EXIT_SUCCESS);
127 }
128 
129 static void
show_all(const char * tag)130 show_all(const char *tag)
131 {
132     int i;
133     int digits;
134     char temp[BUFSIZ];
135     time_t this_time;
136 
137     for (digits = 1, i = num_lines; i > 0; i /= 10) {
138 	++digits;
139     }
140 
141     _nc_SPRINTF(temp, _nc_SLIMIT(sizeof(temp))
142 		"view %.*s", (int) strlen(tag), tag);
143     i = (int) strlen(temp);
144     _nc_SPRINTF(temp + i, _nc_SLIMIT(sizeof(temp) - (size_t) i)
145 		" %.*s", (int) sizeof(temp) - i - 2, fname);
146     move(0, 0);
147     printw("%.*s", COLS, temp);
148     clrtoeol();
149     this_time = time((time_t *) 0);
150     _nc_STRNCPY(temp, ctime(&this_time), (size_t) 30);
151     if ((i = (int) strlen(temp)) != 0) {
152 	temp[--i] = 0;
153 	if (move(0, COLS - i - 2) != ERR)
154 	    printw("  %s", temp);
155     }
156 
157     scrollok(stdscr, FALSE);	/* prevent screen from moving */
158     for (i = 1; i < LINES; i++) {
159 	NCURSES_CH_T *s;
160 	int len;
161 	int actual = (int) (lptr + i - vec_lines);
162 
163 	if (actual > num_lines) {
164 	    if (i < LINES - 1) {
165 		int y, x;
166 		getyx(stdscr, y, x);
167 		move(i, 0);
168 		clrtobot();
169 		move(y, x);
170 	    }
171 	    break;
172 	}
173 	move(i, 0);
174 	printw("%*d:", digits, actual);
175 	clrtoeol();
176 	if ((s = lptr[i - 1]) == 0) {
177 	    continue;
178 	}
179 	len = ch_len(s);
180 	if (len > shift) {
181 #if USE_WIDEC_SUPPORT
182 	    /*
183 	     * An index into an array of cchar_t's is not necessarily the same
184 	     * as the column-offset.  A pad would do this directly.  Here we
185 	     * must translate (or compute a table of offsets).
186 	     */
187 	    {
188 		int j;
189 		int width = 1;
190 
191 		for (j = actual = 0; j < shift; ++j) {
192 		    int count;
193 
194 		    TEST_CCHAR(s + j, count, {
195 			width = wcwidth(test_wch[0]);
196 		    }
197 		    , {
198 			width = 1;
199 		    });
200 		    actual += width;
201 		    if (actual > shift) {
202 			break;
203 		    } else if (actual == shift) {
204 			++j;
205 			break;
206 		    }
207 		}
208 		if (actual < len) {
209 		    if (actual > shift)
210 			addch('<');
211 		    add_wchstr(s + j + (actual > shift));
212 		}
213 	    }
214 #else
215 	    addchstr(s + shift);
216 #endif
217 	}
218 #if defined(NCURSES_VERSION) || defined(HAVE_WCHGAT)
219 	if (try_color)
220 	    wchgat(stdscr, -1, WA_NORMAL, my_pair, NULL);
221 #endif
222     }
223     setscrreg(1, LINES - 1);
224     scrollok(stdscr, TRUE);
225     refresh();
226 }
227 
228 static void
read_file(const char * filename)229 read_file(const char *filename)
230 {
231     FILE *fp;
232     int pass;
233     int k;
234     int width;
235     size_t j;
236     size_t len;
237     struct stat sb;
238     char *my_blob;
239     char **my_vec = 0;
240     WINDOW *my_win;
241 
242     if (stat(filename, &sb) != 0
243 	|| (sb.st_mode & S_IFMT) != S_IFREG) {
244 	failed("input is not a file");
245     }
246 
247     if (sb.st_size == 0) {
248 	failed("input is empty");
249     }
250 
251     if ((fp = fopen(filename, "r")) == 0) {
252 	failed("cannot open input-file");
253     }
254 
255     if ((my_blob = malloc((size_t) sb.st_size + 1)) == 0) {
256 	failed("cannot allocate memory for input-file");
257     }
258 
259     len = fread(my_blob, sizeof(char), (size_t) sb.st_size, fp);
260     fclose(fp);
261 
262     if (len > (size_t) sb.st_size)
263 	len = (size_t) sb.st_size;
264     my_blob[len] = '\0';
265 
266     for (pass = 0; pass < 2; ++pass) {
267 	char *base = my_blob;
268 	k = 0;
269 	for (j = 0; j < len; ++j) {
270 	    if (my_blob[j] == '\n') {
271 		if (pass) {
272 		    my_vec[k] = base;
273 		    my_blob[j] = '\0';
274 		}
275 		base = my_blob + j + 1;
276 		++k;
277 	    }
278 	}
279 	if (base != (my_blob + j)) {
280 	    if (pass)
281 		my_vec[k] = base;
282 	    ++k;
283 	}
284 	num_lines = k;
285 	if (pass == 0) {
286 	    if (((my_vec = typeCalloc(char *, (size_t) k + 2)) == 0)) {
287 		failed("cannot allocate line-vector #1");
288 	    }
289 	} else {
290 	    if (my_vec[0] == NULL)
291 		my_vec[0] = my_blob;
292 	}
293     }
294 
295 #if USE_WIDEC_SUPPORT
296     if (!memcmp("\357\273\277", my_blob, 3)) {
297 	char *s = my_blob + 3;
298 	char *d = my_blob;
299 	Trace(("trim BOM"));
300 	do {
301 	} while ((*d++ = *s++) != '\0');
302     }
303 #endif
304 
305     width = (int) strlen(my_vec[0]);
306     for (k = 1; my_vec[k]; ++k) {
307 	int check = (int) (my_vec[k] - my_vec[k - 1]);
308 	if (width < check)
309 	    width = check;
310     }
311     width = (width + 1) * 5;
312     my_win = newwin(2, width, 0, 0);
313     if (my_win == 0) {
314 	failed("cannot allocate temporary window");
315     }
316 
317     if ((vec_lines = typeCalloc(NCURSES_CH_T *, (size_t) num_lines + 2)) == 0) {
318 	failed("cannot allocate line-vector #2");
319     }
320 
321     /*
322      * Use the curses library for rendering, including tab-conversion.  This
323      * will not make the resulting array's indices correspond to column for
324      * lines containing double-width cells because the "in_wch" functions will
325      * ignore the skipped cells.  Use pads for that sort of thing.
326      */
327     Trace(("slurp the file"));
328     for (k = 0; my_vec[k]; ++k) {
329 	char *s;
330 	int y, x;
331 #if USE_WIDEC_SUPPORT
332 	char *last = my_vec[k] + (int) strlen(my_vec[k]);
333 	wchar_t wch[2];
334 	size_t rc;
335 #ifndef state_unused
336 	mbstate_t state;
337 #endif
338 #endif /* USE_WIDEC_SUPPORT */
339 
340 	werase(my_win);
341 	wmove(my_win, 0, 0);
342 #if USE_WIDEC_SUPPORT
343 	wch[1] = 0;
344 	reset_mbytes(state);
345 #endif
346 	for (s = my_vec[k]; *s != '\0'; ++s) {
347 #if USE_WIDEC_SUPPORT
348 	    if (!n_option) {
349 		rc = (size_t) check_mbytes(wch[0], s, (size_t) (last - s), state);
350 		if ((long) rc == -1 || (long) rc == -2) {
351 		    break;
352 		}
353 		s += rc - 1;
354 		waddwstr(my_win, wch);
355 	    } else
356 #endif
357 		waddch(my_win, *s & 0xff);
358 	}
359 	getyx(my_win, y, x);
360 	if (y)
361 	    x = width - 1;
362 	wmove(my_win, 0, 0);
363 	/* "x + 1" works with standard curses; some implementations are buggy */
364 	if ((vec_lines[k] = typeCalloc(NCURSES_CH_T, x + width + 1)) == 0) {
365 	    failed("cannot allocate line-vector #3");
366 	}
367 #if USE_WIDEC_SUPPORT
368 	win_wchnstr(my_win, vec_lines[k], x);
369 #else
370 	winchnstr(my_win, vec_lines[k], x);
371 #endif
372     }
373 
374     delwin(my_win);
375     free(my_vec);
376     free(my_blob);
377 }
378 
379 static GCC_NORETURN void
usage(int ok)380 usage(int ok)
381 {
382     static const char *msg[] =
383     {
384 	"Usage: view [options] file"
385 	,""
386 	,USAGE_COMMON
387 	,"Options:"
388 	," -c       use color if terminal supports it"
389 	," -i       ignore INT, QUIT, TERM signals"
390 #if USE_WIDEC_SUPPORT
391 	," -n       use waddch (bytes) rather then wadd_wch (wide-chars)"
392 #endif
393 	," -s       start in single-step mode, waiting for input"
394 #ifdef TRACE
395 	," -t       trace screen updates"
396 	," -T NUM   specify trace mask"
397 #endif
398     };
399     size_t n;
400     for (n = 0; n < SIZEOF(msg); n++)
401 	fprintf(stderr, "%s\n", msg[n]);
402     ExitProgram(ok ? EXIT_SUCCESS : EXIT_FAILURE);
403 }
404 /* *INDENT-OFF* */
VERSION_COMMON()405 VERSION_COMMON()
406 /* *INDENT-ON* */
407 
408 int
409 main(int argc, char *argv[])
410 {
411     static const char *help[] =
412     {
413 	"Commands:",
414 	"  q,^Q,ESC       - quit this program",
415 	"",
416 	"  p,<Up>         - scroll the viewport up by one row",
417 	"  n,<Down>       - scroll the viewport down by one row",
418 	"  l,<Left>       - scroll the viewport left by one column",
419 	"  r,<Right>      - scroll the viewport right by one column",
420 	"  <,>            - scroll the viewport left/right by 8 columns",
421 	"",
422 	"  h,<Home>       - scroll the viewport to top of file",
423 	"  ^F,<PageDn>    - scroll to the next page",
424 	"  ^B,<PageUp>    - scroll to the previous page",
425 	"  e,<End>        - scroll the viewport to end of file",
426 	"",
427 	"  ^L             - repaint using redrawwin()",
428 	"",
429 	"  0 through 9    - enter digits for count",
430 	"  s              - use entered count for halfdelay() parameter",
431 	"                 - if no entered count, stop nodelay()",
432 	"  <space>        - begin nodelay()",
433 	0
434     };
435 
436     int ch;
437     int i;
438     int my_delay = 0;
439     NCURSES_CH_T **olptr;
440     int value = 0;
441     bool done = FALSE;
442     bool got_number = FALSE;
443     bool ignore_sigs = FALSE;
444     bool single_step = FALSE;
445     const char *my_label = "Input";
446 
447     setlocale(LC_ALL, "");
448 
449     while ((ch = getopt(argc, argv, OPTS_COMMON "cinstT:")) != -1) {
450 	switch (ch) {
451 	case 'c':
452 	    try_color = TRUE;
453 	    break;
454 	case 'i':
455 	    ignore_sigs = TRUE;
456 	    break;
457 #if USE_WIDEC_SUPPORT
458 	case 'n':
459 	    n_option = TRUE;
460 	    break;
461 #endif
462 	case 's':
463 	    single_step = TRUE;
464 	    break;
465 #ifdef TRACE
466 	case 'T':
467 	    {
468 		char *next = 0;
469 		int tvalue = (int) strtol(optarg, &next, 0);
470 		if (tvalue < 0 || (next != 0 && *next != 0))
471 		    usage(FALSE);
472 		curses_trace((unsigned) tvalue);
473 	    }
474 	    break;
475 	case 't':
476 	    curses_trace(TRACE_CALLS);
477 	    break;
478 #endif
479 	case OPTS_VERSION:
480 	    show_version(argv);
481 	    ExitProgram(EXIT_SUCCESS);
482 	default:
483 	    usage(ch == OPTS_USAGE);
484 	    /* NOTREACHED */
485 	}
486     }
487     if (optind + 1 != argc)
488 	usage(FALSE);
489 
490     InitAndCatch(initscr(), ignore_sigs ? SIG_IGN : finish);
491     keypad(stdscr, TRUE);	/* enable keyboard mapping */
492     (void) nonl();		/* tell curses not to do NL->CR/NL on output */
493     (void) cbreak();		/* take input chars one at a time, no wait for \n */
494     (void) noecho();		/* don't echo input */
495     if (!single_step)
496 	nodelay(stdscr, TRUE);
497     idlok(stdscr, TRUE);	/* allow use of insert/delete line */
498 
499     read_file(fname = argv[optind]);
500 
501     if (try_color) {
502 	if (has_colors()) {
503 	    start_color();
504 	    init_pair(my_pair, COLOR_WHITE, COLOR_BLUE);
505 	    bkgd((chtype) COLOR_PAIR(my_pair));
506 	} else {
507 	    try_color = FALSE;
508 	}
509     }
510 
511     lptr = vec_lines;
512     while (!done) {
513 	int n, c;
514 
515 	if (!got_number)
516 	    show_all(my_label);
517 
518 	for (;;) {
519 	    c = getch();
520 	    if ((c < 127) && isdigit(c)) {
521 		if (!got_number) {
522 		    MvPrintw(0, 0, "Count: ");
523 		    clrtoeol();
524 		}
525 		addch(UChar(c));
526 		value = 10 * value + (c - '0');
527 		got_number = TRUE;
528 	    } else
529 		break;
530 	}
531 	if (got_number && value) {
532 	    n = value;
533 	} else {
534 	    n = 1;
535 	}
536 
537 	if (c != ERR)
538 	    my_label = keyname(c);
539 	switch (c) {
540 	case KEY_DOWN:
541 	case 'n':
542 	    olptr = lptr;
543 	    for (i = 0; i < n; i++)
544 		if ((lptr - vec_lines) < (num_lines - LINES + 1))
545 		    lptr++;
546 		else
547 		    break;
548 	    scrl((int) (lptr - olptr));
549 	    break;
550 
551 	case KEY_UP:
552 	case 'p':
553 	    olptr = lptr;
554 	    for (i = 0; i < n; i++)
555 		if (lptr > vec_lines)
556 		    lptr--;
557 		else
558 		    break;
559 	    scrl((int) (lptr - olptr));
560 	    break;
561 
562 	case 'h':
563 	    /* FALLTHRU */
564 	case KEY_HOME:
565 	    lptr = vec_lines;
566 	    break;
567 
568 	case '<':
569 	    if ((shift -= 8) < 0)
570 		shift = 0;
571 	    break;
572 	case '>':
573 	    shift += 8;
574 	    break;
575 
576 	case 'e':
577 	    /* FALLTHRU */
578 	case KEY_END:
579 	    if (num_lines > LINES)
580 		lptr = (vec_lines + num_lines - LINES + 1);
581 	    else
582 		lptr = (vec_lines + (num_lines - 2));
583 	    break;
584 
585 	case CTRL('F'):
586 	    /* FALLTHRU */
587 	case KEY_NPAGE:
588 	    for (i = 0; i < n; i++) {
589 		if ((lptr - vec_lines) < (num_lines - 5))
590 		    lptr += (LINES - 1);
591 		else
592 		    lptr = (vec_lines + num_lines - 2);
593 	    }
594 	    break;
595 
596 	case CTRL('B'):
597 	    /* FALLTHRU */
598 	case KEY_PPAGE:
599 	    for (i = 0; i < n; i++) {
600 		if ((lptr - vec_lines) >= LINES)
601 		    lptr -= (LINES - 1);
602 		else
603 		    lptr = vec_lines;
604 	    }
605 	    break;
606 
607 	case 'r':
608 	case KEY_RIGHT:
609 	    shift += n;
610 	    break;
611 
612 	case 'l':
613 	case KEY_LEFT:
614 	    shift -= n;
615 	    if (shift < 0) {
616 		shift = 0;
617 		beep();
618 	    }
619 	    break;
620 
621 	case 'q':
622 	case QUIT:
623 	case ESCAPE:
624 	    done = TRUE;
625 	    break;
626 
627 #ifdef KEY_RESIZE
628 	case KEY_RESIZE:	/* ignore this; ncurses will repaint */
629 	    break;
630 #endif
631 	case 's':
632 #if HAVE_HALFDELAY
633 	    if (got_number) {
634 		halfdelay(my_delay = n);
635 	    } else {
636 		nodelay(stdscr, FALSE);
637 		my_delay = -1;
638 	    }
639 #else
640 	    nodelay(stdscr, FALSE);
641 	    my_delay = -1;
642 #endif
643 	    break;
644 	case ' ':
645 	    nodelay(stdscr, TRUE);
646 	    my_delay = 0;
647 	    break;
648 	case CTRL('L'):
649 	    redrawwin(stdscr);
650 	    break;
651 	case ERR:
652 	    if (!my_delay)
653 		napms(50);
654 	    break;
655 	case HELP_KEY_1:
656 	    popup_msg(stdscr, help);
657 	    break;
658 	default:
659 	    beep();
660 	    break;
661 	}
662 	if (c >= KEY_MIN || (c > 0 && !isdigit(c))) {
663 	    got_number = FALSE;
664 	    value = 0;
665 	}
666     }
667 
668     finish(0);			/* we're done */
669 }
670