xref: /original-bsd/old/more/more.c (revision 65ba69af)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 char copyright[] =
20 "@(#) Copyright (c) 1980 Regents of the University of California.\n\
21  All rights reserved.\n";
22 #endif /* not lint */
23 
24 #ifndef lint
25 static char sccsid[] = "@(#)more.c	5.19 (Berkeley) 06/29/88";
26 #endif /* not lint */
27 
28 /*
29 ** more.c - General purpose tty output filter and file perusal program
30 **
31 **	by Eric Shienbrood, UC Berkeley
32 **
33 **	modified by Geoff Peck, UCB to add underlining, single spacing
34 **	modified by John Foderaro, UCB to add -c and MORE environment variable
35 */
36 
37 #include <stdio.h>
38 #include <sys/param.h>
39 #include <ctype.h>
40 #include <signal.h>
41 #include <errno.h>
42 #include <sgtty.h>
43 #include <setjmp.h>
44 #include <sys/stat.h>
45 #include <sys/file.h>
46 #include <a.out.h>
47 #include <varargs.h>
48 
49 #define HELPFILE	"/usr/lib/more.help"
50 #define VI		"/usr/ucb/vi"
51 
52 #define Fopen(s,m)	(Currline = 0,file_pos=0,fopen(s,m))
53 #define Ftell(f)	file_pos
54 #define Fseek(f,off)	(file_pos=off,fseek(f,off,0))
55 #define Getc(f)		(++file_pos, getc(f))
56 #define Ungetc(c,f)	(--file_pos, ungetc(c,f))
57 
58 #define MBIT	CBREAK
59 #define stty(fd,argp)	ioctl(fd,TIOCSETN,argp)
60 
61 #define TBUFSIZ	1024
62 #define LINSIZ	256
63 #define ctrl(letter)	(letter & 077)
64 #define RUBOUT	'\177'
65 #define ESC	'\033'
66 #define QUIT	'\034'
67 
68 struct sgttyb	otty, savetty;
69 long		file_pos, file_size;
70 int		fnum, no_intty, no_tty, slow_tty;
71 int		dum_opt, dlines, onquit(), end_it(), chgwinsz();
72 int		onsusp();
73 int		nscroll = 11;	/* Number of lines scrolled by 'd' */
74 int		fold_opt = 1;	/* Fold long lines */
75 int		stop_opt = 1;	/* Stop after form feeds */
76 int		ssp_opt = 0;	/* Suppress white space */
77 int		ul_opt = 1;	/* Underline as best we can */
78 int		promptlen;
79 int		Currline;	/* Line we are currently at */
80 int		startup = 1;
81 int		firstf = 1;
82 int		notell = 1;
83 int		docrterase = 0;
84 int		docrtkill = 0;
85 int		bad_so;	/* True if overwriting does not turn off standout */
86 int		inwait, Pause, errors;
87 int		within;	/* true if we are within a file,
88 			false if we are between files */
89 int		hard, dumb, noscroll, hardtabs, clreol, eatnl;
90 int		catch_susp;	/* We should catch the SIGTSTP signal */
91 char		**fnames;	/* The list of file names */
92 int		nfiles;		/* Number of files left to process */
93 char		*shell;		/* The name of the shell to use */
94 int		shellp;		/* A previous shell command exists */
95 char		ch;
96 jmp_buf		restore;
97 char		Line[LINSIZ];	/* Line buffer */
98 int		Lpp = 24;	/* lines per page */
99 char		*Clear;		/* clear screen */
100 char		*eraseln;	/* erase line */
101 char		*Senter, *Sexit;/* enter and exit standout mode */
102 char		*ULenter, *ULexit;	/* enter and exit underline mode */
103 char		*chUL;		/* underline character */
104 char		*chBS;		/* backspace character */
105 char		*Home;		/* go to home */
106 char		*cursorm;	/* cursor movement */
107 char		cursorhome[40];	/* contains cursor movement to home */
108 char		*EodClr;	/* clear rest of screen */
109 char		*tgetstr();
110 int		Mcol = 80;	/* number of columns */
111 int		Wrap = 1;	/* set if automargins */
112 int		soglitch;	/* terminal has standout mode glitch */
113 int		ulglitch;	/* terminal has underline mode glitch */
114 int		pstate = 0;	/* current UL state */
115 long		fseek();
116 char		*getenv();
117 struct {
118     long chrctr, line;
119 } context, screen_start;
120 extern char	PC;		/* pad character */
121 extern short	ospeed;
122 
123 
124 main(argc, argv)
125 int argc;
126 char *argv[];
127 {
128     register FILE	*f;
129     register char	*s;
130     register char	*p;
131     register char	ch;
132     register int	left;
133     int			prnames = 0;
134     int			initopt = 0;
135     int			srchopt = 0;
136     int			clearit = 0;
137     int			initline;
138     char		initbuf[80];
139     FILE		*checkf();
140 
141     nfiles = argc;
142     fnames = argv;
143     initterm ();
144     nscroll = Lpp/2 - 1;
145     if (nscroll <= 0)
146 	nscroll = 1;
147     if(s = getenv("MORE")) argscan(s);
148     while (--nfiles > 0) {
149 	if ((ch = (*++fnames)[0]) == '-') {
150 	    argscan(*fnames+1);
151 	}
152 	else if (ch == '+') {
153 	    s = *fnames;
154 	    if (*++s == '/') {
155 		srchopt++;
156 		for (++s, p = initbuf; p < initbuf + 79 && *s != '\0';)
157 		    *p++ = *s++;
158 		*p = '\0';
159 	    }
160 	    else {
161 		initopt++;
162 		for (initline = 0; *s != '\0'; s++)
163 		    if (isdigit (*s))
164 			initline = initline*10 + *s -'0';
165 		--initline;
166 	    }
167 	}
168 	else break;
169     }
170     /* allow clreol only if Home and eraseln and EodClr strings are
171      *  defined, and in that case, make sure we are in noscroll mode
172      */
173     if(clreol)
174     {
175         if((Home == NULL) || (*Home == '\0') ||
176 	   (eraseln == NULL) || (*eraseln == '\0') ||
177            (EodClr == NULL) || (*EodClr == '\0') )
178 	      clreol = 0;
179 	else noscroll = 1;
180     }
181     if (dlines == 0)
182 	dlines = Lpp - (noscroll ? 1 : 2);
183     left = dlines;
184     if (nfiles > 1)
185 	prnames++;
186     if (!no_intty && nfiles == 0) {
187 	char *rindex();
188 
189 	p = rindex(argv[0], '/');
190 	fputs("usage: ",stderr);
191 	fputs(p ? p + 1 : argv[0],stderr);
192 	fputs(" [-dfln] [+linenum | +/pattern] name1 name2 ...\n",stderr);
193 	exit(1);
194     }
195     else
196 	f = stdin;
197     if (!no_tty) {
198 	signal(SIGQUIT, onquit);
199 	signal(SIGINT, end_it);
200 	signal(SIGWINCH, chgwinsz);
201 	if (signal (SIGTSTP, SIG_IGN) == SIG_DFL) {
202 	    signal(SIGTSTP, onsusp);
203 	    catch_susp++;
204 	}
205 	stty (fileno(stderr), &otty);
206     }
207     if (no_intty) {
208 	if (no_tty)
209 	    copy_file (stdin);
210 	else {
211 	    if ((ch = Getc (f)) == '\f')
212 		doclear();
213 	    else {
214 		Ungetc (ch, f);
215 		if (noscroll && (ch != EOF)) {
216 		    if (clreol)
217 			home ();
218 		    else
219 			doclear ();
220 		}
221 	    }
222 	    if (srchopt)
223 	    {
224 		search (initbuf, stdin, 1);
225 		if (noscroll)
226 		    left--;
227 	    }
228 	    else if (initopt)
229 		skiplns (initline, stdin);
230 	    screen (stdin, left);
231 	}
232 	no_intty = 0;
233 	prnames++;
234 	firstf = 0;
235     }
236 
237     while (fnum < nfiles) {
238 	if ((f = checkf (fnames[fnum], &clearit)) != NULL) {
239 	    context.line = context.chrctr = 0;
240 	    Currline = 0;
241 	    if (firstf) setjmp (restore);
242 	    if (firstf) {
243 		firstf = 0;
244 		if (srchopt)
245 		{
246 		    search (initbuf, f, 1);
247 		    if (noscroll)
248 			left--;
249 		}
250 		else if (initopt)
251 		    skiplns (initline, f);
252 	    }
253 	    else if (fnum < nfiles && !no_tty) {
254 		setjmp (restore);
255 		left = command (fnames[fnum], f);
256 	    }
257 	    if (left != 0) {
258 		if ((noscroll || clearit) && (file_size != LONG_MAX))
259 		    if (clreol)
260 			home ();
261 		    else
262 			doclear ();
263 		if (prnames) {
264 		    if (bad_so)
265 			erase (0);
266 		    if (clreol)
267 			cleareol ();
268 		    pr("::::::::::::::");
269 		    if (promptlen > 14)
270 			erase (14);
271 		    printf ("\n");
272 		    if(clreol) cleareol();
273 		    printf("%s\n", fnames[fnum]);
274 		    if(clreol) cleareol();
275 		    printf("::::::::::::::\n");
276 		    if (left > Lpp - 4)
277 			left = Lpp - 4;
278 		}
279 		if (no_tty)
280 		    copy_file (f);
281 		else {
282 		    within++;
283 		    screen(f, left);
284 		    within = 0;
285 		}
286 	    }
287 	    setjmp (restore);
288 	    fflush(stdout);
289 	    fclose(f);
290 	    screen_start.line = screen_start.chrctr = 0L;
291 	    context.line = context.chrctr = 0L;
292 	}
293 	fnum++;
294 	firstf = 0;
295     }
296     reset_tty ();
297     exit(0);
298 }
299 
300 argscan(s)
301 char *s;
302 {
303 	int seen_num = 0;
304 
305 	while (*s != '\0') {
306 		switch (*s) {
307 		  case '0': case '1': case '2':
308 		  case '3': case '4': case '5':
309 		  case '6': case '7': case '8':
310 		  case '9':
311 			if (!seen_num) {
312 				dlines = 0;
313 				seen_num = 1;
314 			}
315 			dlines = dlines*10 + *s - '0';
316 			break;
317 		  case 'd':
318 			dum_opt = 1;
319 			break;
320 		  case 'l':
321 			stop_opt = 0;
322 			break;
323 		  case 'f':
324 			fold_opt = 0;
325 			break;
326 		  case 'p':
327 			noscroll++;
328 			break;
329 		  case 'c':
330 			clreol++;
331 			break;
332 		  case 's':
333 			ssp_opt = 1;
334 			break;
335 		  case 'u':
336 			ul_opt = 0;
337 			break;
338 		}
339 		s++;
340 	}
341 }
342 
343 
344 /*
345 ** Check whether the file named by fs is an ASCII file which the user may
346 ** access.  If it is, return the opened file. Otherwise return NULL.
347 */
348 
349 FILE *
350 checkf (fs, clearfirst)
351 	register char *fs;
352 	int *clearfirst;
353 {
354 	struct stat stbuf;
355 	register FILE *f;
356 	char c;
357 
358 	if (stat (fs, &stbuf) == -1) {
359 		(void)fflush(stdout);
360 		if (clreol)
361 			cleareol ();
362 		perror(fs);
363 		return((FILE *)NULL);
364 	}
365 	if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
366 		printf("\n*** %s: directory ***\n\n", fs);
367 		return((FILE *)NULL);
368 	}
369 	if ((f = Fopen(fs, "r")) == NULL) {
370 		(void)fflush(stdout);
371 		perror(fs);
372 		return((FILE *)NULL);
373 	}
374 	if (magic(f, fs))
375 		return((FILE *)NULL);
376 	c = Getc(f);
377 	*clearfirst = c == '\f';
378 	Ungetc (c, f);
379 	if ((file_size = stbuf.st_size) == 0)
380 		file_size = LONG_MAX;
381 	return(f);
382 }
383 
384 /*
385  * magic --
386  *	check for file magic numbers.  This code would best be shared with
387  *	the file(1) program or, perhaps, more should not try and be so smart?
388  */
389 static
390 magic(f, fs)
391 	FILE *f;
392 	char *fs;
393 {
394 	struct exec ex;
395 
396 	if (fread(&ex, sizeof(ex), 1, f) == 1)
397 		switch(ex.a_magic) {
398 		case OMAGIC:
399 		case NMAGIC:
400 		case ZMAGIC:
401 		case 0405:
402 		case 0411:
403 		case 0177545:
404 			printf("\n******** %s: Not a text file ********\n\n", fs);
405 			(void)fclose(f);
406 			return(1);
407 		}
408 	(void)fseek(f, 0L, L_SET);		/* rewind() not necessary */
409 	return(0);
410 }
411 
412 /*
413 ** A real function, for the tputs routine in termlib
414 */
415 
416 putch (ch)
417 char ch;
418 {
419     putchar (ch);
420 }
421 
422 /*
423 ** Print out the contents of the file f, one screenful at a time.
424 */
425 
426 #define STOP -10
427 
428 screen (f, num_lines)
429 register FILE *f;
430 register int num_lines;
431 {
432     register int c;
433     register int nchars;
434     int length;			/* length of current line */
435     static int prev_len = 1;	/* length of previous line */
436 
437     for (;;) {
438 	while (num_lines > 0 && !Pause) {
439 	    if ((nchars = getline (f, &length)) == EOF)
440 	    {
441 		if (clreol)
442 		    clreos();
443 		return;
444 	    }
445 	    if (ssp_opt && length == 0 && prev_len == 0)
446 		continue;
447 	    prev_len = length;
448 	    if (bad_so || (Senter && *Senter == ' ') && promptlen > 0)
449 		erase (0);
450 	    /* must clear before drawing line since tabs on some terminals
451 	     * do not erase what they tab over.
452 	     */
453 	    if (clreol)
454 		cleareol ();
455 	    prbuf (Line, length);
456 	    if (nchars < promptlen)
457 		erase (nchars);	/* erase () sets promptlen to 0 */
458 	    else promptlen = 0;
459 	    /* is this needed?
460 	     * if (clreol)
461 	     *	cleareol();	/* must clear again in case we wrapped *
462 	     */
463 	    if (nchars < Mcol || !fold_opt)
464 		prbuf("\n", 1);	/* will turn off UL if necessary */
465 	    if (nchars == STOP)
466 		break;
467 	    num_lines--;
468 	}
469 	if (pstate) {
470 		tputs(ULexit, 1, putch);
471 		pstate = 0;
472 	}
473 	fflush(stdout);
474 	if ((c = Getc(f)) == EOF)
475 	{
476 	    if (clreol)
477 		clreos ();
478 	    return;
479 	}
480 
481 	if (Pause && clreol)
482 	    clreos ();
483 	Ungetc (c, f);
484 	setjmp (restore);
485 	Pause = 0; startup = 0;
486 	if ((num_lines = command (NULL, f)) == 0)
487 	    return;
488 	if (hard && promptlen > 0)
489 		erase (0);
490 	if (noscroll && num_lines >= dlines)
491 	{
492 	    if (clreol)
493 		home();
494 	    else
495 		doclear ();
496 	}
497 	screen_start.line = Currline;
498 	screen_start.chrctr = Ftell (f);
499     }
500 }
501 
502 /*
503 ** Come here if a quit signal is received
504 */
505 
506 onquit()
507 {
508     signal(SIGQUIT, SIG_IGN);
509     if (!inwait) {
510 	putchar ('\n');
511 	if (!startup) {
512 	    signal(SIGQUIT, onquit);
513 	    longjmp (restore, 1);
514 	}
515 	else
516 	    Pause++;
517     }
518     else if (!dum_opt && notell) {
519 	write (2, "[Use q or Q to quit]", 20);
520 	promptlen += 20;
521 	notell = 0;
522     }
523     signal(SIGQUIT, onquit);
524 }
525 
526 /*
527 ** Come here if a signal for a window size change is received
528 */
529 
530 chgwinsz()
531 {
532     struct winsize win;
533 
534     (void) signal(SIGWINCH, SIG_IGN);
535     if (ioctl(fileno(stdout), TIOCGWINSZ, &win) != -1) {
536 	if (win.ws_row != 0) {
537 	    Lpp = win.ws_row;
538 	    nscroll = Lpp/2 - 1;
539 	    if (nscroll <= 0)
540 		nscroll = 1;
541 	    dlines = Lpp - (noscroll ? 1 : 2);
542 	}
543 	if (win.ws_col != 0)
544 	    Mcol = win.ws_col;
545     }
546     (void) signal(SIGWINCH, chgwinsz);
547 }
548 
549 /*
550 ** Clean up terminal state and exit. Also come here if interrupt signal received
551 */
552 
553 end_it ()
554 {
555 
556     reset_tty ();
557     if (clreol) {
558 	putchar ('\r');
559 	clreos ();
560 	fflush (stdout);
561     }
562     else if (!clreol && (promptlen > 0)) {
563 	kill_line ();
564 	fflush (stdout);
565     }
566     else
567 	write (2, "\n", 1);
568     _exit(0);
569 }
570 
571 copy_file(f)
572 register FILE *f;
573 {
574     register int c;
575 
576     while ((c = getc(f)) != EOF)
577 	putchar(c);
578 }
579 
580 /* Simplified printf function */
581 
582 printf (fmt, va_alist)
583 register char *fmt;
584 va_dcl
585 {
586 	va_list ap;
587 	register char ch;
588 	register int ccount;
589 
590 	ccount = 0;
591 	va_start(ap);
592 	while (*fmt) {
593 		while ((ch = *fmt++) != '%') {
594 			if (ch == '\0')
595 				return (ccount);
596 			ccount++;
597 			putchar (ch);
598 		}
599 		switch (*fmt++) {
600 		case 'd':
601 			ccount += printd (va_arg(ap, int));
602 			break;
603 		case 's':
604 			ccount += pr (va_arg(ap, char *));
605 			break;
606 		case '%':
607 			ccount++;
608 			putchar ('%');
609 			break;
610 		case '0':
611 			return (ccount);
612 		default:
613 			break;
614 		}
615 	}
616 	va_end(ap);
617 	return (ccount);
618 
619 }
620 
621 /*
622 ** Print an integer as a string of decimal digits,
623 ** returning the length of the print representation.
624 */
625 
626 printd (n)
627 int n;
628 {
629     int a, nchars;
630 
631     if (a = n/10)
632 	nchars = 1 + printd(a);
633     else
634 	nchars = 1;
635     putchar (n % 10 + '0');
636     return (nchars);
637 }
638 
639 /* Put the print representation of an integer into a string */
640 static char *sptr;
641 
642 scanstr (n, str)
643 int n;
644 char *str;
645 {
646     sptr = str;
647     Sprintf (n);
648     *sptr = '\0';
649 }
650 
651 Sprintf (n)
652 {
653     int a;
654 
655     if (a = n/10)
656 	Sprintf (a);
657     *sptr++ = n % 10 + '0';
658 }
659 
660 static char bell = ctrl('G');
661 
662 strlen (s)
663 char *s;
664 {
665     register char *p;
666 
667     p = s;
668     while (*p++)
669 	;
670     return (p - s - 1);
671 }
672 
673 /* See whether the last component of the path name "path" is equal to the
674 ** string "string"
675 */
676 
677 tailequ (path, string)
678 char *path;
679 register char *string;
680 {
681 	register char *tail;
682 
683 	tail = path + strlen(path);
684 	while (tail >= path)
685 		if (*(--tail) == '/')
686 			break;
687 	++tail;
688 	while (*tail++ == *string++)
689 		if (*tail == '\0')
690 			return(1);
691 	return(0);
692 }
693 
694 prompt (filename)
695 char *filename;
696 {
697     if (clreol)
698 	cleareol ();
699     else if (promptlen > 0)
700 	kill_line ();
701     if (!hard) {
702 	promptlen = 8;
703 	if (Senter && Sexit) {
704 	    tputs (Senter, 1, putch);
705 	    promptlen += (2 * soglitch);
706 	}
707 	if (clreol)
708 	    cleareol ();
709 	pr("--More--");
710 	if (filename != NULL) {
711 	    promptlen += printf ("(Next file: %s)", filename);
712 	}
713 	else if (!no_intty) {
714 	    promptlen += printf ("(%d%%)", (int)((file_pos * 100) / file_size));
715 	}
716 	if (dum_opt) {
717 	    promptlen += pr("[Press space to continue, 'q' to quit.]");
718 	}
719 	if (Senter && Sexit)
720 	    tputs (Sexit, 1, putch);
721 	if (clreol)
722 	    clreos ();
723 	fflush(stdout);
724     }
725     else
726 	write (2, &bell, 1);
727     inwait++;
728 }
729 
730 /*
731 ** Get a logical line
732 */
733 
734 getline(f, length)
735 register FILE *f;
736 int *length;
737 {
738     register int	c;
739     register char	*p;
740     register int	column;
741     static int		colflg;
742 
743     p = Line;
744     column = 0;
745     c = Getc (f);
746     if (colflg && c == '\n') {
747 	Currline++;
748 	c = Getc (f);
749     }
750     while (p < &Line[LINSIZ - 1]) {
751 	if (c == EOF) {
752 	    if (p > Line) {
753 		*p = '\0';
754 		*length = p - Line;
755 		return (column);
756 	    }
757 	    *length = p - Line;
758 	    return (EOF);
759 	}
760 	if (c == '\n') {
761 	    Currline++;
762 	    break;
763 	}
764 	*p++ = c;
765 	if (c == '\t')
766 	    if (!hardtabs || column < promptlen && !hard) {
767 		if (hardtabs && eraseln && !dumb) {
768 		    column = 1 + (column | 7);
769 		    tputs (eraseln, 1, putch);
770 		    promptlen = 0;
771 		}
772 		else {
773 		    for (--p; p < &Line[LINSIZ - 1];) {
774 			*p++ = ' ';
775 			if ((++column & 7) == 0)
776 			    break;
777 		    }
778 		    if (column >= promptlen) promptlen = 0;
779 		}
780 	    }
781 	    else
782 		column = 1 + (column | 7);
783 	else if (c == '\b' && column > 0)
784 	    column--;
785 	else if (c == '\r')
786 	    column = 0;
787 	else if (c == '\f' && stop_opt) {
788 		p[-1] = '^';
789 		*p++ = 'L';
790 		column += 2;
791 		Pause++;
792 	}
793 	else if (c == EOF) {
794 	    *length = p - Line;
795 	    return (column);
796 	}
797 	else if (c >= ' ' && c != RUBOUT)
798 	    column++;
799 	if (column >= Mcol && fold_opt) break;
800 	c = Getc (f);
801     }
802     if (column >= Mcol && Mcol > 0) {
803 	if (!Wrap) {
804 	    *p++ = '\n';
805 	}
806     }
807     colflg = column == Mcol && fold_opt;
808     if (colflg && eatnl && Wrap) {
809 	*p++ = '\n'; /* simulate normal wrap */
810     }
811     *length = p - Line;
812     *p = 0;
813     return (column);
814 }
815 
816 /*
817 ** Erase the rest of the prompt, assuming we are starting at column col.
818 */
819 
820 erase (col)
821 register int col;
822 {
823 
824     if (promptlen == 0)
825 	return;
826     if (hard) {
827 	putchar ('\n');
828     }
829     else {
830 	if (col == 0)
831 	    putchar ('\r');
832 	if (!dumb && eraseln)
833 	    tputs (eraseln, 1, putch);
834 	else
835 	    for (col = promptlen - col; col > 0; col--)
836 		putchar (' ');
837     }
838     promptlen = 0;
839 }
840 
841 /*
842 ** Erase the current line entirely
843 */
844 
845 kill_line ()
846 {
847     erase (0);
848     if (!eraseln || dumb) putchar ('\r');
849 }
850 
851 /*
852  * force clear to end of line
853  */
854 cleareol()
855 {
856     tputs(eraseln, 1, putch);
857 }
858 
859 clreos()
860 {
861     tputs(EodClr, 1, putch);
862 }
863 
864 /*
865 **  Print string and return number of characters
866 */
867 
868 pr(s1)
869 char	*s1;
870 {
871     register char	*s;
872     register char	c;
873 
874     for (s = s1; c = *s++; )
875 	putchar(c);
876     return (s - s1 - 1);
877 }
878 
879 
880 /* Print a buffer of n characters */
881 
882 prbuf (s, n)
883 register char *s;
884 register int n;
885 {
886     register char c;			/* next output character */
887     register int state;			/* next output char's UL state */
888 #define wouldul(s,n)	((n) >= 2 && (((s)[0] == '_' && (s)[1] == '\b') || ((s)[1] == '\b' && (s)[2] == '_')))
889 
890     while (--n >= 0)
891 	if (!ul_opt)
892 	    putchar (*s++);
893 	else {
894 	    if (*s == ' ' && pstate == 0 && ulglitch && wouldul(s+1, n-1)) {
895 		s++;
896 		continue;
897 	    }
898 	    if (state = wouldul(s, n)) {
899 		c = (*s == '_')? s[2] : *s ;
900 		n -= 2;
901 		s += 3;
902 	    } else
903 		c = *s++;
904 	    if (state != pstate) {
905 		if (c == ' ' && state == 0 && ulglitch && wouldul(s, n-1))
906 		    state = 1;
907 		else
908 		    tputs(state ? ULenter : ULexit, 1, putch);
909 	    }
910 	    if (c != ' ' || pstate == 0 || state != 0 || ulglitch == 0)
911 	        putchar(c);
912 	    if (state && *chUL) {
913 		pr(chBS);
914 		tputs(chUL, 1, putch);
915 	    }
916 	    pstate = state;
917 	}
918 }
919 
920 /*
921 **  Clear the screen
922 */
923 
924 doclear()
925 {
926     if (Clear && !hard) {
927 	tputs(Clear, 1, putch);
928 
929 	/* Put out carriage return so that system doesn't
930 	** get confused by escape sequences when expanding tabs
931 	*/
932 	putchar ('\r');
933 	promptlen = 0;
934     }
935 }
936 
937 /*
938  * Go to home position
939  */
940 home()
941 {
942     tputs(Home,1,putch);
943 }
944 
945 static int lastcmd, lastarg, lastp;
946 static int lastcolon;
947 char shell_line[132];
948 
949 /*
950 ** Read a command and do it. A command consists of an optional integer
951 ** argument followed by the command character.  Return the number of lines
952 ** to display in the next screenful.  If there is nothing more to display
953 ** in the current file, zero is returned.
954 */
955 
956 command (filename, f)
957 char *filename;
958 register FILE *f;
959 {
960     register int nlines;
961     register int retval;
962     register char c;
963     char colonch;
964     FILE *helpf;
965     int done;
966     char comchar, cmdbuf[80], *p;
967 
968 #define ret(val) retval=val;done++;break
969 
970     done = 0;
971     if (!errors)
972 	prompt (filename);
973     else
974 	errors = 0;
975     if (MBIT == RAW && slow_tty) {
976 	otty.sg_flags |= MBIT;
977 	stty(fileno(stderr), &otty);
978     }
979     for (;;) {
980 	nlines = number (&comchar);
981 	lastp = colonch = 0;
982 	if (comchar == '.') {	/* Repeat last command */
983 		lastp++;
984 		comchar = lastcmd;
985 		nlines = lastarg;
986 		if (lastcmd == ':')
987 			colonch = lastcolon;
988 	}
989 	lastcmd = comchar;
990 	lastarg = nlines;
991 	if (comchar == otty.sg_erase) {
992 	    kill_line ();
993 	    prompt (filename);
994 	    continue;
995 	}
996 	switch (comchar) {
997 	case ':':
998 	    retval = colon (filename, colonch, nlines);
999 	    if (retval >= 0)
1000 		done++;
1001 	    break;
1002 	case 'b':
1003 	case ctrl('B'):
1004 	    {
1005 		register int initline;
1006 
1007 		if (no_intty) {
1008 		    write(2, &bell, 1);
1009 		    return (-1);
1010 		}
1011 
1012 		if (nlines == 0) nlines++;
1013 
1014 		putchar ('\r');
1015 		erase (0);
1016 		printf ("\n");
1017 		if (clreol)
1018 			cleareol ();
1019 		printf ("...back %d page", nlines);
1020 		if (nlines > 1)
1021 			pr ("s\n");
1022 		else
1023 			pr ("\n");
1024 
1025 		if (clreol)
1026 			cleareol ();
1027 		pr ("\n");
1028 
1029 		initline = Currline - dlines * (nlines + 1);
1030 		if (! noscroll)
1031 		    --initline;
1032 		if (initline < 0) initline = 0;
1033 		Fseek(f, 0L);
1034 		Currline = 0;	/* skiplns() will make Currline correct */
1035 		skiplns(initline, f);
1036 		if (! noscroll) {
1037 		    ret(dlines + 1);
1038 		}
1039 		else {
1040 		    ret(dlines);
1041 		}
1042 	    }
1043 	case ' ':
1044 	case 'z':
1045 	    if (nlines == 0) nlines = dlines;
1046 	    else if (comchar == 'z') dlines = nlines;
1047 	    ret (nlines);
1048 	case 'd':
1049 	case ctrl('D'):
1050 	    if (nlines != 0) nscroll = nlines;
1051 	    ret (nscroll);
1052 	case 'q':
1053 	case 'Q':
1054 	    end_it ();
1055 	case 's':
1056 	case 'f':
1057 	    if (nlines == 0) nlines++;
1058 	    if (comchar == 'f')
1059 		nlines *= dlines;
1060 	    putchar ('\r');
1061 	    erase (0);
1062 	    printf ("\n");
1063 	    if (clreol)
1064 		cleareol ();
1065 	    printf ("...skipping %d line", nlines);
1066 	    if (nlines > 1)
1067 		pr ("s\n");
1068 	    else
1069 		pr ("\n");
1070 
1071 	    if (clreol)
1072 		cleareol ();
1073 	    pr ("\n");
1074 
1075 	    while (nlines > 0) {
1076 		while ((c = Getc (f)) != '\n')
1077 		    if (c == EOF) {
1078 			retval = 0;
1079 			done++;
1080 			goto endsw;
1081 		    }
1082 		    Currline++;
1083 		    nlines--;
1084 	    }
1085 	    ret (dlines);
1086 	case '\n':
1087 	    if (nlines != 0)
1088 		dlines = nlines;
1089 	    else
1090 		nlines = 1;
1091 	    ret (nlines);
1092 	case '\f':
1093 	    if (!no_intty) {
1094 		doclear ();
1095 		Fseek (f, screen_start.chrctr);
1096 		Currline = screen_start.line;
1097 		ret (dlines);
1098 	    }
1099 	    else {
1100 		write (2, &bell, 1);
1101 		break;
1102 	    }
1103 	case '\'':
1104 	    if (!no_intty) {
1105 		kill_line ();
1106 		pr ("\n***Back***\n\n");
1107 		Fseek (f, context.chrctr);
1108 		Currline = context.line;
1109 		ret (dlines);
1110 	    }
1111 	    else {
1112 		write (2, &bell, 1);
1113 		break;
1114 	    }
1115 	case '=':
1116 	    kill_line ();
1117 	    promptlen = printd (Currline);
1118 	    fflush (stdout);
1119 	    break;
1120 	case 'n':
1121 	    lastp++;
1122 	case '/':
1123 	    if (nlines == 0) nlines++;
1124 	    kill_line ();
1125 	    pr ("/");
1126 	    promptlen = 1;
1127 	    fflush (stdout);
1128 	    if (lastp) {
1129 		write (2,"\r", 1);
1130 		search (NULL, f, nlines);	/* Use previous r.e. */
1131 	    }
1132 	    else {
1133 		ttyin (cmdbuf, 78, '/');
1134 		write (2, "\r", 1);
1135 		search (cmdbuf, f, nlines);
1136 	    }
1137 	    ret (dlines-1);
1138 	case '!':
1139 	    do_shell (filename);
1140 	    break;
1141 	case '?':
1142 	case 'h':
1143 	    if ((helpf = fopen (HELPFILE, "r")) == NULL)
1144 		error ("Can't open help file");
1145 	    if (noscroll) doclear ();
1146 	    copy_file (helpf);
1147 	    fclose (helpf);
1148 	    prompt (filename);
1149 	    break;
1150 	case 'v':	/* This case should go right before default */
1151 	    if (!no_intty) {
1152 		kill_line ();
1153 		cmdbuf[0] = '+';
1154 		scanstr (Currline - dlines < 0 ? 0
1155 				: Currline - (dlines + 1) / 2, &cmdbuf[1]);
1156 		pr ("vi "); pr (cmdbuf); putchar (' '); pr (fnames[fnum]);
1157 		execute (filename, VI, "vi", cmdbuf, fnames[fnum], 0);
1158 		break;
1159 	    }
1160 	default:
1161 	    if (dum_opt) {
1162    		kill_line ();
1163 		if (Senter && Sexit) {
1164 		    tputs (Senter, 1, putch);
1165 		    promptlen = pr ("[Press 'h' for instructions.]") + (2 * soglitch);
1166 		    tputs (Sexit, 1, putch);
1167 		}
1168 		else
1169 		    promptlen = pr ("[Press 'h' for instructions.]");
1170 		fflush (stdout);
1171 	    }
1172 	    else
1173 		write (2, &bell, 1);
1174 	    break;
1175 	}
1176 	if (done) break;
1177     }
1178     putchar ('\r');
1179 endsw:
1180     inwait = 0;
1181     notell++;
1182     if (MBIT == RAW && slow_tty) {
1183 	otty.sg_flags &= ~MBIT;
1184 	stty(fileno(stderr), &otty);
1185     }
1186     return (retval);
1187 }
1188 
1189 char ch;
1190 
1191 /*
1192  * Execute a colon-prefixed command.
1193  * Returns <0 if not a command that should cause
1194  * more of the file to be printed.
1195  */
1196 
1197 colon (filename, cmd, nlines)
1198 char *filename;
1199 int cmd;
1200 int nlines;
1201 {
1202 	if (cmd == 0)
1203 		ch = readch ();
1204 	else
1205 		ch = cmd;
1206 	lastcolon = ch;
1207 	switch (ch) {
1208 	case 'f':
1209 		kill_line ();
1210 		if (!no_intty)
1211 			promptlen = printf ("\"%s\" line %d", fnames[fnum], Currline);
1212 		else
1213 			promptlen = printf ("[Not a file] line %d", Currline);
1214 		fflush (stdout);
1215 		return (-1);
1216 	case 'n':
1217 		if (nlines == 0) {
1218 			if (fnum >= nfiles - 1)
1219 				end_it ();
1220 			nlines++;
1221 		}
1222 		putchar ('\r');
1223 		erase (0);
1224 		skipf (nlines);
1225 		return (0);
1226 	case 'p':
1227 		if (no_intty) {
1228 			write (2, &bell, 1);
1229 			return (-1);
1230 		}
1231 		putchar ('\r');
1232 		erase (0);
1233 		if (nlines == 0)
1234 			nlines++;
1235 		skipf (-nlines);
1236 		return (0);
1237 	case '!':
1238 		do_shell (filename);
1239 		return (-1);
1240 	case 'q':
1241 	case 'Q':
1242 		end_it ();
1243 	default:
1244 		write (2, &bell, 1);
1245 		return (-1);
1246 	}
1247 }
1248 
1249 /*
1250 ** Read a decimal number from the terminal. Set cmd to the non-digit which
1251 ** terminates the number.
1252 */
1253 
1254 number(cmd)
1255 char *cmd;
1256 {
1257 	register int i;
1258 
1259 	i = 0; ch = otty.sg_kill;
1260 	for (;;) {
1261 		ch = readch ();
1262 		if (ch >= '0' && ch <= '9')
1263 			i = i*10 + ch - '0';
1264 		else if (ch == otty.sg_kill)
1265 			i = 0;
1266 		else {
1267 			*cmd = ch;
1268 			break;
1269 		}
1270 	}
1271 	return (i);
1272 }
1273 
1274 do_shell (filename)
1275 char *filename;
1276 {
1277 	char cmdbuf[80];
1278 
1279 	kill_line ();
1280 	pr ("!");
1281 	fflush (stdout);
1282 	promptlen = 1;
1283 	if (lastp)
1284 		pr (shell_line);
1285 	else {
1286 		ttyin (cmdbuf, 78, '!');
1287 		if (expand (shell_line, cmdbuf)) {
1288 			kill_line ();
1289 			promptlen = printf ("!%s", shell_line);
1290 		}
1291 	}
1292 	fflush (stdout);
1293 	write (2, "\n", 1);
1294 	promptlen = 0;
1295 	shellp = 1;
1296 	execute (filename, shell, shell, "-c", shell_line, 0);
1297 }
1298 
1299 /*
1300 ** Search for nth ocurrence of regular expression contained in buf in the file
1301 */
1302 
1303 search (buf, file, n)
1304 char buf[];
1305 FILE *file;
1306 register int n;
1307 {
1308     long startline = Ftell (file);
1309     register long line1 = startline;
1310     register long line2 = startline;
1311     register long line3 = startline;
1312     register int lncount;
1313     int saveln, rv, re_exec();
1314     char *s, *re_comp();
1315 
1316     context.line = saveln = Currline;
1317     context.chrctr = startline;
1318     lncount = 0;
1319     if ((s = re_comp (buf)) != 0)
1320 	error (s);
1321     while (!feof (file)) {
1322 	line3 = line2;
1323 	line2 = line1;
1324 	line1 = Ftell (file);
1325 	rdline (file);
1326 	lncount++;
1327 	if ((rv = re_exec (Line)) == 1)
1328 		if (--n == 0) {
1329 		    if (lncount > 3 || (lncount > 1 && no_intty))
1330 		    {
1331 			pr ("\n");
1332 			if (clreol)
1333 			    cleareol ();
1334 			pr("...skipping\n");
1335 		    }
1336 		    if (!no_intty) {
1337 			Currline -= (lncount >= 3 ? 3 : lncount);
1338 			Fseek (file, line3);
1339 			if (noscroll)
1340 			    if (clreol) {
1341 				home ();
1342 				cleareol ();
1343 			    }
1344 			    else
1345 				doclear ();
1346 		    }
1347 		    else {
1348 			kill_line ();
1349 			if (noscroll)
1350 			    if (clreol) {
1351 			        home ();
1352 			        cleareol ();
1353 			    }
1354 			    else
1355 				doclear ();
1356 			pr (Line);
1357 			putchar ('\n');
1358 		    }
1359 		    break;
1360 		}
1361 	else if (rv == -1)
1362 	    error ("Regular expression botch");
1363     }
1364     if (feof (file)) {
1365 	if (!no_intty) {
1366 	    file->_flag &= ~_IOEOF; /* why doesn't fseek do this ??!!??! */
1367 	    Currline = saveln;
1368 	    Fseek (file, startline);
1369 	}
1370 	else {
1371 	    pr ("\nPattern not found\n");
1372 	    end_it ();
1373 	}
1374 	error ("Pattern not found");
1375     }
1376 }
1377 
1378 /*VARARGS2*/
1379 execute (filename, cmd, va_alist)
1380 char *filename;
1381 char *cmd;
1382 va_dcl
1383 {
1384 	int id;
1385 	int n;
1386 	va_list argp;
1387 
1388 	fflush (stdout);
1389 	reset_tty ();
1390 	for (n = 10; (id = fork ()) < 0 && n > 0; n--)
1391 	    sleep (5);
1392 	if (id == 0) {
1393 	    if (!isatty(0)) {
1394 		close(0);
1395 		open("/dev/tty", 0);
1396 	    }
1397 	    va_start(argp);
1398 	    execv (cmd, argp);
1399 	    write (2, "exec failed\n", 12);
1400 	    exit (1);
1401 	    va_end(argp);	/* balance {}'s for some UNIX's */
1402 	}
1403 	if (id > 0) {
1404 	    signal (SIGINT, SIG_IGN);
1405 	    signal (SIGQUIT, SIG_IGN);
1406 	    if (catch_susp)
1407 		signal(SIGTSTP, SIG_DFL);
1408 	    while (wait(0) > 0);
1409 	    signal (SIGINT, end_it);
1410 	    signal (SIGQUIT, onquit);
1411 	    if (catch_susp)
1412 		signal(SIGTSTP, onsusp);
1413 	} else
1414 	    write(2, "can't fork\n", 11);
1415 	set_tty ();
1416 	pr ("------------------------\n");
1417 	prompt (filename);
1418 }
1419 /*
1420 ** Skip n lines in the file f
1421 */
1422 
1423 skiplns (n, f)
1424 register int n;
1425 register FILE *f;
1426 {
1427     register char c;
1428 
1429     while (n > 0) {
1430 	while ((c = Getc (f)) != '\n')
1431 	    if (c == EOF)
1432 		return;
1433 	    n--;
1434 	    Currline++;
1435     }
1436 }
1437 
1438 /*
1439 ** Skip nskip files in the file list (from the command line). Nskip may be
1440 ** negative.
1441 */
1442 
1443 skipf (nskip)
1444 register int nskip;
1445 {
1446     if (nskip == 0) return;
1447     if (nskip > 0) {
1448 	if (fnum + nskip > nfiles - 1)
1449 	    nskip = nfiles - fnum - 1;
1450     }
1451     else if (within)
1452 	++fnum;
1453     fnum += nskip;
1454     if (fnum < 0)
1455 	fnum = 0;
1456     pr ("\n...Skipping ");
1457     pr ("\n");
1458     if (clreol)
1459 	cleareol ();
1460     pr ("...Skipping ");
1461     pr (nskip > 0 ? "to file " : "back to file ");
1462     pr (fnames[fnum]);
1463     pr ("\n");
1464     if (clreol)
1465 	cleareol ();
1466     pr ("\n");
1467     --fnum;
1468 }
1469 
1470 /*----------------------------- Terminal I/O -------------------------------*/
1471 
1472 initterm ()
1473 {
1474     char	buf[TBUFSIZ];
1475     static char	clearbuf[TBUFSIZ];
1476     char	*clearptr, *padstr;
1477     int		ldisc;
1478     int		lmode;
1479     char	*term;
1480     int		tgrp;
1481     struct winsize win;
1482 
1483 retry:
1484     if (!(no_tty = gtty(fileno(stdout), &otty))) {
1485 	if (ioctl(fileno(stdout), TIOCLGET, &lmode) < 0) {
1486 	    perror("TIOCLGET");
1487 	    exit(1);
1488 	}
1489 	docrterase = ((lmode & LCRTERA) != 0);
1490 	docrtkill = ((lmode & LCRTKIL) != 0);
1491 	/*
1492 	 * Wait until we're in the foreground before we save the
1493 	 * the terminal modes.
1494 	 */
1495 	if (ioctl(fileno(stdout), TIOCGPGRP, &tgrp) < 0) {
1496 	    perror("TIOCGPGRP");
1497 	    exit(1);
1498 	}
1499 	if (tgrp != getpgrp(0)) {
1500 	    kill(0, SIGTTOU);
1501 	    goto retry;
1502 	}
1503 	if ((term = getenv("TERM")) == 0 || tgetent(buf, term) <= 0) {
1504 	    dumb++; ul_opt = 0;
1505 	}
1506 	else {
1507 	    if (ioctl(fileno(stdout), TIOCGWINSZ, &win) < 0) {
1508 		Lpp = tgetnum("li");
1509 		Mcol = tgetnum("co");
1510 	    } else {
1511 		if ((Lpp = win.ws_row) == 0)
1512 		    Lpp = tgetnum("li");
1513 		if ((Mcol = win.ws_col) == 0)
1514 		    Mcol = tgetnum("co");
1515 	    }
1516 	    if ((Lpp <= 0) || tgetflag("hc")) {
1517 		hard++;	/* Hard copy terminal */
1518 		Lpp = 24;
1519 	    }
1520 	    if (tgetflag("xn"))
1521 		eatnl++; /* Eat newline at last column + 1; dec, concept */
1522 	    if (Mcol <= 0)
1523 		Mcol = 80;
1524 
1525 	    if (tailequ (fnames[0], "page") || !hard && tgetflag("ns"))
1526 		noscroll++;
1527 	    Wrap = tgetflag("am");
1528 	    bad_so = tgetflag ("xs");
1529 	    clearptr = clearbuf;
1530 	    eraseln = tgetstr("ce",&clearptr);
1531 	    Clear = tgetstr("cl", &clearptr);
1532 	    Senter = tgetstr("so", &clearptr);
1533 	    Sexit = tgetstr("se", &clearptr);
1534 	    if ((soglitch = tgetnum("sg")) < 0)
1535 		soglitch = 0;
1536 
1537 	    /*
1538 	     *  Set up for underlining:  some terminals don't need it;
1539 	     *  others have start/stop sequences, still others have an
1540 	     *  underline char sequence which is assumed to move the
1541 	     *  cursor forward one character.  If underline sequence
1542 	     *  isn't available, settle for standout sequence.
1543 	     */
1544 
1545 	    if (tgetflag("ul") || tgetflag("os"))
1546 		ul_opt = 0;
1547 	    if ((chUL = tgetstr("uc", &clearptr)) == NULL )
1548 		chUL = "";
1549 	    if (((ULenter = tgetstr("us", &clearptr)) == NULL ||
1550 	         (ULexit = tgetstr("ue", &clearptr)) == NULL) && !*chUL) {
1551 	        if ((ULenter = Senter) == NULL || (ULexit = Sexit) == NULL) {
1552 			ULenter = "";
1553 			ULexit = "";
1554 		} else
1555 			ulglitch = soglitch;
1556 	    } else {
1557 		if ((ulglitch = tgetnum("ug")) < 0)
1558 		    ulglitch = 0;
1559 	    }
1560 
1561 	    if (padstr = tgetstr("pc", &clearptr))
1562 		PC = *padstr;
1563 	    Home = tgetstr("ho",&clearptr);
1564 	    if (Home == 0 || *Home == '\0')
1565 	    {
1566 		if ((cursorm = tgetstr("cm", &clearptr)) != NULL) {
1567 		    strcpy(cursorhome, tgoto(cursorm, 0, 0));
1568 		    Home = cursorhome;
1569 	       }
1570 	    }
1571 	    EodClr = tgetstr("cd", &clearptr);
1572 	    if ((chBS = tgetstr("bc", &clearptr)) == NULL)
1573 		chBS = "\b";
1574 
1575 	}
1576 	if ((shell = getenv("SHELL")) == NULL)
1577 	    shell = "/bin/sh";
1578     }
1579     no_intty = gtty(fileno(stdin), &otty);
1580     gtty(fileno(stderr), &otty);
1581     savetty = otty;
1582     ospeed = otty.sg_ospeed;
1583     slow_tty = ospeed < B1200;
1584     hardtabs = (otty.sg_flags & TBDELAY) != XTABS;
1585     if (!no_tty) {
1586 	otty.sg_flags &= ~ECHO;
1587 	if (MBIT == CBREAK || !slow_tty)
1588 	    otty.sg_flags |= MBIT;
1589     }
1590 }
1591 
1592 readch ()
1593 {
1594 	char ch;
1595 	extern int errno;
1596 
1597 	errno = 0;
1598 	if (read (2, &ch, 1) <= 0)
1599 		if (errno != EINTR)
1600 			end_it();
1601 		else
1602 			ch = otty.sg_kill;
1603 	return (ch);
1604 }
1605 
1606 static char BS = '\b';
1607 static char *BSB = "\b \b";
1608 static char CARAT = '^';
1609 #define ERASEONECHAR \
1610     if (docrterase) \
1611 	write (2, BSB, sizeof(BSB)); \
1612     else \
1613 	write (2, &BS, sizeof(BS));
1614 
1615 ttyin (buf, nmax, pchar)
1616 char buf[];
1617 register int nmax;
1618 char pchar;
1619 {
1620     register char *sptr;
1621     register char ch;
1622     register int slash = 0;
1623     int	maxlen;
1624     char cbuf;
1625 
1626     sptr = buf;
1627     maxlen = 0;
1628     while (sptr - buf < nmax) {
1629 	if (promptlen > maxlen) maxlen = promptlen;
1630 	ch = readch ();
1631 	if (ch == '\\') {
1632 	    slash++;
1633 	}
1634 	else if ((ch == otty.sg_erase) && !slash) {
1635 	    if (sptr > buf) {
1636 		--promptlen;
1637 		ERASEONECHAR
1638 		--sptr;
1639 		if ((*sptr < ' ' && *sptr != '\n') || *sptr == RUBOUT) {
1640 		    --promptlen;
1641 		    ERASEONECHAR
1642 		}
1643 		continue;
1644 	    }
1645 	    else {
1646 		if (!eraseln) promptlen = maxlen;
1647 		longjmp (restore, 1);
1648 	    }
1649 	}
1650 	else if ((ch == otty.sg_kill) && !slash) {
1651 	    if (hard) {
1652 		show (ch);
1653 		putchar ('\n');
1654 		putchar (pchar);
1655 	    }
1656 	    else {
1657 		putchar ('\r');
1658 		putchar (pchar);
1659 		if (eraseln)
1660 		    erase (1);
1661 		else if (docrtkill)
1662 		    while (promptlen-- > 1)
1663 			write (2, BSB, sizeof(BSB));
1664 		promptlen = 1;
1665 	    }
1666 	    sptr = buf;
1667 	    fflush (stdout);
1668 	    continue;
1669 	}
1670 	if (slash && (ch == otty.sg_kill || ch == otty.sg_erase)) {
1671 	    ERASEONECHAR
1672 	    --sptr;
1673 	}
1674 	if (ch != '\\')
1675 	    slash = 0;
1676 	*sptr++ = ch;
1677 	if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1678 	    ch += ch == RUBOUT ? -0100 : 0100;
1679 	    write (2, &CARAT, 1);
1680 	    promptlen++;
1681 	}
1682 	cbuf = ch;
1683 	if (ch != '\n' && ch != ESC) {
1684 	    write (2, &cbuf, 1);
1685 	    promptlen++;
1686 	}
1687 	else
1688 	    break;
1689     }
1690     *--sptr = '\0';
1691     if (!eraseln) promptlen = maxlen;
1692     if (sptr - buf >= nmax - 1)
1693 	error ("Line too long");
1694 }
1695 
1696 expand (outbuf, inbuf)
1697 char *outbuf;
1698 char *inbuf;
1699 {
1700     register char *instr;
1701     register char *outstr;
1702     register char ch;
1703     char temp[200];
1704     int changed = 0;
1705 
1706     instr = inbuf;
1707     outstr = temp;
1708     while ((ch = *instr++) != '\0')
1709 	switch (ch) {
1710 	case '%':
1711 	    if (!no_intty) {
1712 		strcpy (outstr, fnames[fnum]);
1713 		outstr += strlen (fnames[fnum]);
1714 		changed++;
1715 	    }
1716 	    else
1717 		*outstr++ = ch;
1718 	    break;
1719 	case '!':
1720 	    if (!shellp)
1721 		error ("No previous command to substitute for");
1722 	    strcpy (outstr, shell_line);
1723 	    outstr += strlen (shell_line);
1724 	    changed++;
1725 	    break;
1726 	case '\\':
1727 	    if (*instr == '%' || *instr == '!') {
1728 		*outstr++ = *instr++;
1729 		break;
1730 	    }
1731 	default:
1732 	    *outstr++ = ch;
1733 	}
1734     *outstr++ = '\0';
1735     strcpy (outbuf, temp);
1736     return (changed);
1737 }
1738 
1739 show (ch)
1740 register char ch;
1741 {
1742     char cbuf;
1743 
1744     if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1745 	ch += ch == RUBOUT ? -0100 : 0100;
1746 	write (2, &CARAT, 1);
1747 	promptlen++;
1748     }
1749     cbuf = ch;
1750     write (2, &cbuf, 1);
1751     promptlen++;
1752 }
1753 
1754 error (mess)
1755 char *mess;
1756 {
1757     if (clreol)
1758 	cleareol ();
1759     else
1760 	kill_line ();
1761     promptlen += strlen (mess);
1762     if (Senter && Sexit) {
1763 	tputs (Senter, 1, putch);
1764 	pr(mess);
1765 	tputs (Sexit, 1, putch);
1766     }
1767     else
1768 	pr (mess);
1769     fflush(stdout);
1770     errors++;
1771     longjmp (restore, 1);
1772 }
1773 
1774 
1775 set_tty ()
1776 {
1777 	otty.sg_flags |= MBIT;
1778 	otty.sg_flags &= ~ECHO;
1779 	stty(fileno(stderr), &otty);
1780 }
1781 
1782 reset_tty ()
1783 {
1784     if (no_tty)
1785 	return;
1786     if (pstate) {
1787 	tputs(ULexit, 1, putch);
1788 	fflush(stdout);
1789 	pstate = 0;
1790     }
1791     otty.sg_flags |= ECHO;
1792     otty.sg_flags &= ~MBIT;
1793     stty(fileno(stderr), &savetty);
1794 }
1795 
1796 rdline (f)
1797 register FILE *f;
1798 {
1799     register char c;
1800     register char *p;
1801 
1802     p = Line;
1803     while ((c = Getc (f)) != '\n' && c != EOF && p - Line < LINSIZ - 1)
1804 	*p++ = c;
1805     if (c == '\n')
1806 	Currline++;
1807     *p = '\0';
1808 }
1809 
1810 /* Come here when we get a suspend signal from the terminal */
1811 
1812 onsusp ()
1813 {
1814     /* ignore SIGTTOU so we don't get stopped if csh grabs the tty */
1815     signal(SIGTTOU, SIG_IGN);
1816     reset_tty ();
1817     fflush (stdout);
1818     signal(SIGTTOU, SIG_DFL);
1819     /* Send the TSTP signal to suspend our process group */
1820     signal(SIGTSTP, SIG_DFL);
1821     sigsetmask(0);
1822     kill (0, SIGTSTP);
1823     /* Pause for station break */
1824 
1825     /* We're back */
1826     signal (SIGTSTP, onsusp);
1827     set_tty ();
1828     if (inwait)
1829 	    longjmp (restore);
1830 }
1831