xref: /csrg-svn/old/more/more.c (revision 31125)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  */
6 
7 #ifndef lint
8 char copyright[] =
9 "@(#) Copyright (c) 1980 Regents of the University of California.\n\
10  All rights reserved.\n";
11 #endif not lint
12 
13 #ifndef lint
14 static char sccsid[] = "@(#)more.c	5.12 (Berkeley) 05/13/87";
15 #endif not lint
16 
17 /*
18 ** more.c - General purpose tty output filter and file perusal program
19 **
20 **	by Eric Shienbrood, UC Berkeley
21 **
22 **	modified by Geoff Peck, UCB to add underlining, single spacing
23 **	modified by John Foderaro, UCB to add -c and MORE environment variable
24 */
25 
26 #include <stdio.h>
27 #include <sys/types.h>
28 #include <ctype.h>
29 #include <signal.h>
30 #include <errno.h>
31 #include <sgtty.h>
32 #include <setjmp.h>
33 #include <sys/stat.h>
34 #include <sys/file.h>
35 #include <sys/exec.h>
36 
37 #define HELPFILE	"/usr/lib/more.help"
38 #define VI		"/usr/ucb/vi"
39 
40 #define Fopen(s,m)	(Currline = 0,file_pos=0,fopen(s,m))
41 #define Ftell(f)	file_pos
42 #define Fseek(f,off)	(file_pos=off,fseek(f,off,0))
43 #define Getc(f)		(++file_pos, getc(f))
44 #define Ungetc(c,f)	(--file_pos, ungetc(c,f))
45 
46 #define MBIT	CBREAK
47 #define stty(fd,argp)	ioctl(fd,TIOCSETN,argp)
48 
49 #define TBUFSIZ	1024
50 #define LINSIZ	256
51 #define ctrl(letter)	('letter' & 077)
52 #define RUBOUT	'\177'
53 #define ESC	'\033'
54 #define QUIT	'\034'
55 
56 struct sgttyb	otty, savetty;
57 long		file_pos, file_size;
58 int		fnum, no_intty, no_tty, slow_tty;
59 int		dum_opt, dlines, onquit(), end_it(), chgwinsz();
60 int		onsusp();
61 int		nscroll = 11;	/* Number of lines scrolled by 'd' */
62 int		fold_opt = 1;	/* Fold long lines */
63 int		stop_opt = 1;	/* Stop after form feeds */
64 int		ssp_opt = 0;	/* Suppress white space */
65 int		ul_opt = 1;	/* Underline as best we can */
66 int		promptlen;
67 int		Currline;	/* Line we are currently at */
68 int		startup = 1;
69 int		firstf = 1;
70 int		notell = 1;
71 int		docrterase = 0;
72 int		docrtkill = 0;
73 int		bad_so;	/* True if overwriting does not turn off standout */
74 int		inwait, Pause, errors;
75 int		within;	/* true if we are within a file,
76 			false if we are between files */
77 int		hard, dumb, noscroll, hardtabs, clreol, eatnl;
78 int		catch_susp;	/* We should catch the SIGTSTP signal */
79 char		**fnames;	/* The list of file names */
80 int		nfiles;		/* Number of files left to process */
81 char		*shell;		/* The name of the shell to use */
82 int		shellp;		/* A previous shell command exists */
83 char		ch;
84 jmp_buf		restore;
85 char		Line[LINSIZ];	/* Line buffer */
86 int		Lpp = 24;	/* lines per page */
87 char		*Clear;		/* clear screen */
88 char		*eraseln;	/* erase line */
89 char		*Senter, *Sexit;/* enter and exit standout mode */
90 char		*ULenter, *ULexit;	/* enter and exit underline mode */
91 char		*chUL;		/* underline character */
92 char		*chBS;		/* backspace character */
93 char		*Home;		/* go to home */
94 char		*cursorm;	/* cursor movement */
95 char		cursorhome[40];	/* contains cursor movement to home */
96 char		*EodClr;	/* clear rest of screen */
97 char		*tgetstr();
98 int		Mcol = 80;	/* number of columns */
99 int		Wrap = 1;	/* set if automargins */
100 int		soglitch;	/* terminal has standout mode glitch */
101 int		ulglitch;	/* terminal has underline mode glitch */
102 int		pstate = 0;	/* current UL state */
103 long		fseek();
104 char		*getenv();
105 struct {
106     long chrctr, line;
107 } context, screen_start;
108 extern char	PC;		/* pad character */
109 extern short	ospeed;
110 
111 
112 main(argc, argv)
113 int argc;
114 char *argv[];
115 {
116     register FILE	*f;
117     register char	*s;
118     register char	*p;
119     register char	ch;
120     register int	left;
121     int			prnames = 0;
122     int			initopt = 0;
123     int			srchopt = 0;
124     int			clearit = 0;
125     int			initline;
126     char		initbuf[80];
127     FILE		*checkf();
128 
129     nfiles = argc;
130     fnames = argv;
131     initterm ();
132     nscroll = Lpp/2 - 1;
133     if (nscroll <= 0)
134 	nscroll = 1;
135     if(s = getenv("MORE")) argscan(s);
136     while (--nfiles > 0) {
137 	if ((ch = (*++fnames)[0]) == '-') {
138 	    argscan(*fnames+1);
139 	}
140 	else if (ch == '+') {
141 	    s = *fnames;
142 	    if (*++s == '/') {
143 		srchopt++;
144 		for (++s, p = initbuf; p < initbuf + 79 && *s != '\0';)
145 		    *p++ = *s++;
146 		*p = '\0';
147 	    }
148 	    else {
149 		initopt++;
150 		for (initline = 0; *s != '\0'; s++)
151 		    if (isdigit (*s))
152 			initline = initline*10 + *s -'0';
153 		--initline;
154 	    }
155 	}
156 	else break;
157     }
158     /* allow clreol only if Home and eraseln and EodClr strings are
159      *  defined, and in that case, make sure we are in noscroll mode
160      */
161     if(clreol)
162     {
163         if((Home == NULL) || (*Home == '\0') ||
164 	   (eraseln == NULL) || (*eraseln == '\0') ||
165            (EodClr == NULL) || (*EodClr == '\0') )
166 	      clreol = 0;
167 	else noscroll = 1;
168     }
169     if (dlines == 0)
170 	dlines = Lpp - (noscroll ? 1 : 2);
171     left = dlines;
172     if (nfiles > 1)
173 	prnames++;
174     if (!no_intty && nfiles == 0) {
175 	fputs("Usage: ",stderr);
176 	fputs(argv[0],stderr);
177 	fputs(" [-dfln] [+linenum | +/pattern] name1 name2 ...\n",stderr);
178 	exit(1);
179     }
180     else
181 	f = stdin;
182     if (!no_tty) {
183 	signal(SIGQUIT, onquit);
184 	signal(SIGINT, end_it);
185 	signal(SIGWINCH, chgwinsz);
186 	if (signal (SIGTSTP, SIG_IGN) == SIG_DFL) {
187 	    signal(SIGTSTP, onsusp);
188 	    catch_susp++;
189 	}
190 	stty (fileno(stderr), &otty);
191     }
192     if (no_intty) {
193 	if (no_tty)
194 	    copy_file (stdin);
195 	else {
196 	    if ((ch = Getc (f)) == '\f')
197 		doclear();
198 	    else {
199 		Ungetc (ch, f);
200 		if (noscroll && (ch != EOF)) {
201 		    if (clreol)
202 			home ();
203 		    else
204 			doclear ();
205 		}
206 	    }
207 	    if (srchopt)
208 	    {
209 		search (initbuf, stdin, 1);
210 		if (noscroll)
211 		    left--;
212 	    }
213 	    else if (initopt)
214 		skiplns (initline, stdin);
215 	    screen (stdin, left);
216 	}
217 	no_intty = 0;
218 	prnames++;
219 	firstf = 0;
220     }
221 
222     while (fnum < nfiles) {
223 	if ((f = checkf (fnames[fnum], &clearit)) != NULL) {
224 	    context.line = context.chrctr = 0;
225 	    Currline = 0;
226 	    if (firstf) setjmp (restore);
227 	    if (firstf) {
228 		firstf = 0;
229 		if (srchopt)
230 		{
231 		    search (initbuf, f, 1);
232 		    if (noscroll)
233 			left--;
234 		}
235 		else if (initopt)
236 		    skiplns (initline, f);
237 	    }
238 	    else if (fnum < nfiles && !no_tty) {
239 		setjmp (restore);
240 		left = command (fnames[fnum], f);
241 	    }
242 	    if (left != 0) {
243 		if ((noscroll || clearit) && (file_size != 0x7fffffffffffffffL))
244 		    if (clreol)
245 			home ();
246 		    else
247 			doclear ();
248 		if (prnames) {
249 		    if (bad_so)
250 			erase (0);
251 		    if (clreol)
252 			cleareol ();
253 		    pr("::::::::::::::");
254 		    if (promptlen > 14)
255 			erase (14);
256 		    printf ("\n");
257 		    if(clreol) cleareol();
258 		    printf("%s\n", fnames[fnum]);
259 		    if(clreol) cleareol();
260 		    printf("::::::::::::::\n");
261 		    if (left > Lpp - 4)
262 			left = Lpp - 4;
263 		}
264 		if (no_tty)
265 		    copy_file (f);
266 		else {
267 		    within++;
268 		    screen(f, left);
269 		    within = 0;
270 		}
271 	    }
272 	    setjmp (restore);
273 	    fflush(stdout);
274 	    fclose(f);
275 	    screen_start.line = screen_start.chrctr = 0L;
276 	    context.line = context.chrctr = 0L;
277 	}
278 	fnum++;
279 	firstf = 0;
280     }
281     reset_tty ();
282     exit(0);
283 }
284 
285 argscan(s)
286 char *s;
287 {
288 	for (dlines = 0; *s != '\0'; s++)
289 	{
290 		switch (*s)
291 		{
292 		  case '0': case '1': case '2':
293 		  case '3': case '4': case '5':
294 		  case '6': case '7': case '8':
295 		  case '9':
296 			dlines = dlines*10 + *s - '0';
297 			break;
298 		  case 'd':
299 			dum_opt = 1;
300 			break;
301 		  case 'l':
302 			stop_opt = 0;
303 			break;
304 		  case 'f':
305 			fold_opt = 0;
306 			break;
307 		  case 'p':
308 			noscroll++;
309 			break;
310 		  case 'c':
311 			clreol++;
312 			break;
313 		  case 's':
314 			ssp_opt = 1;
315 			break;
316 		  case 'u':
317 			ul_opt = 0;
318 			break;
319 		}
320 	}
321 }
322 
323 
324 /*
325 ** Check whether the file named by fs is an ASCII file which the user may
326 ** access.  If it is, return the opened file. Otherwise return NULL.
327 */
328 
329 FILE *
330 checkf (fs, clearfirst)
331 register char *fs;
332 int *clearfirst;
333 {
334     struct stat stbuf;
335     register FILE *f;
336     char c;
337 
338     if (stat (fs, &stbuf) == -1) {
339 	fflush(stdout);
340 	if (clreol)
341 	    cleareol ();
342 	perror(fs);
343 	return (NULL);
344     }
345     if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
346 	printf("\n*** %s: directory ***\n\n", fs);
347 	return (NULL);
348     }
349     if ((f=Fopen(fs, "r")) == NULL) {
350 	fflush(stdout);
351 	perror(fs);
352 	return (NULL);
353     }
354     /* Try to see whether it is an ASCII file */
355     if (magic(f)) {
356 	printf("\n******** %s: Not a text file ********\n\n", fs);
357 	fclose (f);
358 	return (NULL);
359     }
360     c = Getc(f);
361     if (c == '\f')
362 	*clearfirst = 1;
363     else {
364 	*clearfirst = 0;
365 	Ungetc (c, f);
366     }
367     if ((file_size = stbuf.st_size) == 0)
368 	file_size = 0x7fffffffffffffffL;
369     return (f);
370 }
371 
372 /*
373  * Check for file magic numbers. This code would best
374  * be shared with the file(1) program or, perhaps, more
375  * should not try and be so smart?
376  */
377 magic(f)
378     FILE *f;
379 {
380     long magic;
381 
382     magic = getw(f);
383     if (ftell(f) < sizeof magic)
384     	rewind(f);				/* reset file position */
385     else
386     	fseek(f, -sizeof (magic), L_INCR);	/* reset file position */
387     return (magic == 0405 || magic == OMAGIC || magic == NMAGIC ||
388 	magic == 0411 || magic == ZMAGIC || magic == 0177545);
389 }
390 
391 /*
392 ** A real function, for the tputs routine in termlib
393 */
394 
395 putch (ch)
396 char ch;
397 {
398     putchar (ch);
399 }
400 
401 /*
402 ** Print out the contents of the file f, one screenful at a time.
403 */
404 
405 #define STOP -10
406 
407 screen (f, num_lines)
408 register FILE *f;
409 register int num_lines;
410 {
411     register int c;
412     register int nchars;
413     int length;			/* length of current line */
414     static int prev_len = 1;	/* length of previous line */
415 
416     for (;;) {
417 	while (num_lines > 0 && !Pause) {
418 	    if ((nchars = getline (f, &length)) == EOF)
419 	    {
420 		if (clreol)
421 		    clreos();
422 		return;
423 	    }
424 	    if (ssp_opt && length == 0 && prev_len == 0)
425 		continue;
426 	    prev_len = length;
427 	    if (bad_so || (Senter && *Senter == ' ') && promptlen > 0)
428 		erase (0);
429 	    /* must clear before drawing line since tabs on some terminals
430 	     * do not erase what they tab over.
431 	     */
432 	    if (clreol)
433 		cleareol ();
434 	    prbuf (Line, length);
435 	    if (nchars < promptlen)
436 		erase (nchars);	/* erase () sets promptlen to 0 */
437 	    else promptlen = 0;
438 	    /* is this needed?
439 	     * if (clreol)
440 	     *	cleareol();	/* must clear again in case we wrapped *
441 	     */
442 	    if (nchars < Mcol || !fold_opt)
443 		prbuf("\n", 1);	/* will turn off UL if necessary */
444 	    if (nchars == STOP)
445 		break;
446 	    num_lines--;
447 	}
448 	if (pstate) {
449 		tputs(ULexit, 1, putch);
450 		pstate = 0;
451 	}
452 	fflush(stdout);
453 	if ((c = Getc(f)) == EOF)
454 	{
455 	    if (clreol)
456 		clreos ();
457 	    return;
458 	}
459 
460 	if (Pause && clreol)
461 	    clreos ();
462 	Ungetc (c, f);
463 	setjmp (restore);
464 	Pause = 0; startup = 0;
465 	if ((num_lines = command (NULL, f)) == 0)
466 	    return;
467 	if (hard && promptlen > 0)
468 		erase (0);
469 	if (noscroll && num_lines >= dlines)
470 	{
471 	    if (clreol)
472 		home();
473 	    else
474 		doclear ();
475 	}
476 	screen_start.line = Currline;
477 	screen_start.chrctr = Ftell (f);
478     }
479 }
480 
481 /*
482 ** Come here if a quit signal is received
483 */
484 
485 onquit()
486 {
487     signal(SIGQUIT, SIG_IGN);
488     if (!inwait) {
489 	putchar ('\n');
490 	if (!startup) {
491 	    signal(SIGQUIT, onquit);
492 	    longjmp (restore, 1);
493 	}
494 	else
495 	    Pause++;
496     }
497     else if (!dum_opt && notell) {
498 	write (2, "[Use q or Q to quit]", 20);
499 	promptlen += 20;
500 	notell = 0;
501     }
502     signal(SIGQUIT, onquit);
503 }
504 
505 /*
506 ** Come here if a signal for a window size change is received
507 */
508 
509 chgwinsz()
510 {
511     struct winsize win;
512 
513     (void) signal(SIGWINCH, SIG_IGN);
514     if (ioctl(fileno(stdout), TIOCGWINSZ, &win) != -1) {
515 	if (win.ws_row != 0) {
516 	    Lpp = win.ws_row;
517 	    nscroll = Lpp/2 - 1;
518 	    if (nscroll <= 0)
519 		nscroll = 1;
520 	    dlines = Lpp - (noscroll ? 1 : 2);
521 	}
522 	if (win.ws_col != 0)
523 	    Mcol = win.ws_col;
524     }
525     (void) signal(SIGWINCH, chgwinsz);
526 }
527 
528 /*
529 ** Clean up terminal state and exit. Also come here if interrupt signal received
530 */
531 
532 end_it ()
533 {
534 
535     reset_tty ();
536     if (clreol) {
537 	putchar ('\r');
538 	clreos ();
539 	fflush (stdout);
540     }
541     else if (!clreol && (promptlen > 0)) {
542 	kill_line ();
543 	fflush (stdout);
544     }
545     else
546 	write (2, "\n", 1);
547     _exit(0);
548 }
549 
550 copy_file(f)
551 register FILE *f;
552 {
553     register int c;
554 
555     while ((c = getc(f)) != EOF)
556 	putchar(c);
557 }
558 
559 /* Simplified printf function */
560 
561 printf (fmt, args)
562 register char *fmt;
563 int args;
564 {
565 	register int *argp;
566 	register char ch;
567 	register int ccount;
568 
569 	ccount = 0;
570 	argp = &args;
571 	while (*fmt) {
572 		while ((ch = *fmt++) != '%') {
573 			if (ch == '\0')
574 				return (ccount);
575 			ccount++;
576 			putchar (ch);
577 		}
578 		switch (*fmt++) {
579 		case 'd':
580 			ccount += printd (*argp);
581 			break;
582 		case 's':
583 			ccount += pr ((char *)*argp);
584 			break;
585 		case '%':
586 			ccount++;
587 			argp--;
588 			putchar ('%');
589 			break;
590 		case '0':
591 			return (ccount);
592 		default:
593 			break;
594 		}
595 		++argp;
596 	}
597 	return (ccount);
598 
599 }
600 
601 /*
602 ** Print an integer as a string of decimal digits,
603 ** returning the length of the print representation.
604 */
605 
606 printd (n)
607 int n;
608 {
609     int a, nchars;
610 
611     if (a = n/10)
612 	nchars = 1 + printd(a);
613     else
614 	nchars = 1;
615     putchar (n % 10 + '0');
616     return (nchars);
617 }
618 
619 /* Put the print representation of an integer into a string */
620 static char *sptr;
621 
622 scanstr (n, str)
623 int n;
624 char *str;
625 {
626     sptr = str;
627     Sprintf (n);
628     *sptr = '\0';
629 }
630 
631 Sprintf (n)
632 {
633     int a;
634 
635     if (a = n/10)
636 	Sprintf (a);
637     *sptr++ = n % 10 + '0';
638 }
639 
640 static char bell = ctrl(G);
641 
642 strlen (s)
643 char *s;
644 {
645     register char *p;
646 
647     p = s;
648     while (*p++)
649 	;
650     return (p - s - 1);
651 }
652 
653 /* See whether the last component of the path name "path" is equal to the
654 ** string "string"
655 */
656 
657 tailequ (path, string)
658 char *path;
659 register char *string;
660 {
661 	register char *tail;
662 
663 	tail = path + strlen(path);
664 	while (tail >= path)
665 		if (*(--tail) == '/')
666 			break;
667 	++tail;
668 	while (*tail++ == *string++)
669 		if (*tail == '\0')
670 			return(1);
671 	return(0);
672 }
673 
674 prompt (filename)
675 char *filename;
676 {
677     if (clreol)
678 	cleareol ();
679     else if (promptlen > 0)
680 	kill_line ();
681     if (!hard) {
682 	promptlen = 8;
683 	if (Senter && Sexit) {
684 	    tputs (Senter, 1, putch);
685 	    promptlen += (2 * soglitch);
686 	}
687 	if (clreol)
688 	    cleareol ();
689 	pr("--More--");
690 	if (filename != NULL) {
691 	    promptlen += printf ("(Next file: %s)", filename);
692 	}
693 	else if (!no_intty) {
694 	    promptlen += printf ("(%d%%)", (int)((file_pos * 100) / file_size));
695 	}
696 	if (dum_opt) {
697 	    promptlen += pr("[Press space to continue, 'q' to quit.]");
698 	}
699 	if (Senter && Sexit)
700 	    tputs (Sexit, 1, putch);
701 	if (clreol)
702 	    clreos ();
703 	fflush(stdout);
704     }
705     else
706 	write (2, &bell, 1);
707     inwait++;
708 }
709 
710 /*
711 ** Get a logical line
712 */
713 
714 getline(f, length)
715 register FILE *f;
716 int *length;
717 {
718     register int	c;
719     register char	*p;
720     register int	column;
721     static int		colflg;
722 
723     p = Line;
724     column = 0;
725     c = Getc (f);
726     if (colflg && c == '\n') {
727 	Currline++;
728 	c = Getc (f);
729     }
730     while (p < &Line[LINSIZ - 1]) {
731 	if (c == EOF) {
732 	    if (p > Line) {
733 		*p = '\0';
734 		*length = p - Line;
735 		return (column);
736 	    }
737 	    *length = p - Line;
738 	    return (EOF);
739 	}
740 	if (c == '\n') {
741 	    Currline++;
742 	    break;
743 	}
744 	*p++ = c;
745 	if (c == '\t')
746 	    if (!hardtabs || column < promptlen && !hard) {
747 		if (hardtabs && eraseln && !dumb) {
748 		    column = 1 + (column | 7);
749 		    tputs (eraseln, 1, putch);
750 		    promptlen = 0;
751 		}
752 		else {
753 		    for (--p; p < &Line[LINSIZ - 1];) {
754 			*p++ = ' ';
755 			if ((++column & 7) == 0)
756 			    break;
757 		    }
758 		    if (column >= promptlen) promptlen = 0;
759 		}
760 	    }
761 	    else
762 		column = 1 + (column | 7);
763 	else if (c == '\b' && column > 0)
764 	    column--;
765 	else if (c == '\r')
766 	    column = 0;
767 	else if (c == '\f' && stop_opt) {
768 		p[-1] = '^';
769 		*p++ = 'L';
770 		column += 2;
771 		Pause++;
772 	}
773 	else if (c == EOF) {
774 	    *length = p - Line;
775 	    return (column);
776 	}
777 	else if (c >= ' ' && c != RUBOUT)
778 	    column++;
779 	if (column >= Mcol && fold_opt) break;
780 	c = Getc (f);
781     }
782     if (column >= Mcol && Mcol > 0) {
783 	if (!Wrap) {
784 	    *p++ = '\n';
785 	}
786     }
787     colflg = column == Mcol && fold_opt;
788     if (colflg && eatnl && Wrap) {
789 	*p++ = '\n'; /* simulate normal wrap */
790     }
791     *length = p - Line;
792     *p = 0;
793     return (column);
794 }
795 
796 /*
797 ** Erase the rest of the prompt, assuming we are starting at column col.
798 */
799 
800 erase (col)
801 register int col;
802 {
803 
804     if (promptlen == 0)
805 	return;
806     if (hard) {
807 	putchar ('\n');
808     }
809     else {
810 	if (col == 0)
811 	    putchar ('\r');
812 	if (!dumb && eraseln)
813 	    tputs (eraseln, 1, putch);
814 	else
815 	    for (col = promptlen - col; col > 0; col--)
816 		putchar (' ');
817     }
818     promptlen = 0;
819 }
820 
821 /*
822 ** Erase the current line entirely
823 */
824 
825 kill_line ()
826 {
827     erase (0);
828     if (!eraseln || dumb) putchar ('\r');
829 }
830 
831 /*
832  * force clear to end of line
833  */
834 cleareol()
835 {
836     tputs(eraseln, 1, putch);
837 }
838 
839 clreos()
840 {
841     tputs(EodClr, 1, putch);
842 }
843 
844 /*
845 **  Print string and return number of characters
846 */
847 
848 pr(s1)
849 char	*s1;
850 {
851     register char	*s;
852     register char	c;
853 
854     for (s = s1; c = *s++; )
855 	putchar(c);
856     return (s - s1 - 1);
857 }
858 
859 
860 /* Print a buffer of n characters */
861 
862 prbuf (s, n)
863 register char *s;
864 register int n;
865 {
866     register char c;			/* next output character */
867     register int state;			/* next output char's UL state */
868 #define wouldul(s,n)	((n) >= 2 && (((s)[0] == '_' && (s)[1] == '\b') || ((s)[1] == '\b' && (s)[2] == '_')))
869 
870     while (--n >= 0)
871 	if (!ul_opt)
872 	    putchar (*s++);
873 	else {
874 	    if (*s == ' ' && pstate == 0 && ulglitch && wouldul(s+1, n-1)) {
875 		s++;
876 		continue;
877 	    }
878 	    if (state = wouldul(s, n)) {
879 		c = (*s == '_')? s[2] : *s ;
880 		n -= 2;
881 		s += 3;
882 	    } else
883 		c = *s++;
884 	    if (state != pstate) {
885 		if (c == ' ' && state == 0 && ulglitch && wouldul(s, n-1))
886 		    state = 1;
887 		else
888 		    tputs(state ? ULenter : ULexit, 1, putch);
889 	    }
890 	    if (c != ' ' || pstate == 0 || state != 0 || ulglitch == 0)
891 	        putchar(c);
892 	    if (state && *chUL) {
893 		pr(chBS);
894 		tputs(chUL, 1, putch);
895 	    }
896 	    pstate = state;
897 	}
898 }
899 
900 /*
901 **  Clear the screen
902 */
903 
904 doclear()
905 {
906     if (Clear && !hard) {
907 	tputs(Clear, 1, putch);
908 
909 	/* Put out carriage return so that system doesn't
910 	** get confused by escape sequences when expanding tabs
911 	*/
912 	putchar ('\r');
913 	promptlen = 0;
914     }
915 }
916 
917 /*
918  * Go to home position
919  */
920 home()
921 {
922     tputs(Home,1,putch);
923 }
924 
925 static int lastcmd, lastarg, lastp;
926 static int lastcolon;
927 char shell_line[132];
928 
929 /*
930 ** Read a command and do it. A command consists of an optional integer
931 ** argument followed by the command character.  Return the number of lines
932 ** to display in the next screenful.  If there is nothing more to display
933 ** in the current file, zero is returned.
934 */
935 
936 command (filename, f)
937 char *filename;
938 register FILE *f;
939 {
940     register int nlines;
941     register int retval;
942     register char c;
943     char colonch;
944     FILE *helpf;
945     int done;
946     char comchar, cmdbuf[80], *p;
947 
948 #define ret(val) retval=val;done++;break
949 
950     done = 0;
951     if (!errors)
952 	prompt (filename);
953     else
954 	errors = 0;
955     if (MBIT == RAW && slow_tty) {
956 	otty.sg_flags |= MBIT;
957 	stty(fileno(stderr), &otty);
958     }
959     for (;;) {
960 	nlines = number (&comchar);
961 	lastp = colonch = 0;
962 	if (comchar == '.') {	/* Repeat last command */
963 		lastp++;
964 		comchar = lastcmd;
965 		nlines = lastarg;
966 		if (lastcmd == ':')
967 			colonch = lastcolon;
968 	}
969 	lastcmd = comchar;
970 	lastarg = nlines;
971 	if (comchar == otty.sg_erase) {
972 	    kill_line ();
973 	    prompt (filename);
974 	    continue;
975 	}
976 	switch (comchar) {
977 	case ':':
978 	    retval = colon (filename, colonch, nlines);
979 	    if (retval >= 0)
980 		done++;
981 	    break;
982 	case 'b':
983 	case ctrl(B):
984 	    {
985 		register int initline;
986 
987 		if (no_intty) {
988 		    write(2, &bell, 1);
989 		    return (-1);
990 		}
991 
992 		if (nlines == 0) nlines++;
993 
994 		putchar ('\r');
995 		erase (0);
996 		printf ("\n");
997 		if (clreol)
998 			cleareol ();
999 		printf ("...back %d page", nlines);
1000 		if (nlines > 1)
1001 			pr ("s\n");
1002 		else
1003 			pr ("\n");
1004 
1005 		if (clreol)
1006 			cleareol ();
1007 		pr ("\n");
1008 
1009 		initline = Currline - dlines * (nlines + 1);
1010 		if (! noscroll)
1011 		    --initline;
1012 		if (initline < 0) initline = 0;
1013 		Fseek(f, 0L);
1014 		Currline = 0;	/* skiplns() will make Currline correct */
1015 		skiplns(initline, f);
1016 		if (! noscroll) {
1017 		    ret(dlines + 1);
1018 		}
1019 		else {
1020 		    ret(dlines);
1021 		}
1022 	    }
1023 	case ' ':
1024 	case 'z':
1025 	    if (nlines == 0) nlines = dlines;
1026 	    else if (comchar == 'z') dlines = nlines;
1027 	    ret (nlines);
1028 	case 'd':
1029 	case ctrl(D):
1030 	    if (nlines != 0) nscroll = nlines;
1031 	    ret (nscroll);
1032 	case 'q':
1033 	case 'Q':
1034 	    end_it ();
1035 	case 's':
1036 	case 'f':
1037 	    if (nlines == 0) nlines++;
1038 	    if (comchar == 'f')
1039 		nlines *= dlines;
1040 	    putchar ('\r');
1041 	    erase (0);
1042 	    printf ("\n");
1043 	    if (clreol)
1044 		cleareol ();
1045 	    printf ("...skipping %d line", nlines);
1046 	    if (nlines > 1)
1047 		pr ("s\n");
1048 	    else
1049 		pr ("\n");
1050 
1051 	    if (clreol)
1052 		cleareol ();
1053 	    pr ("\n");
1054 
1055 	    while (nlines > 0) {
1056 		while ((c = Getc (f)) != '\n')
1057 		    if (c == EOF) {
1058 			retval = 0;
1059 			done++;
1060 			goto endsw;
1061 		    }
1062 		    Currline++;
1063 		    nlines--;
1064 	    }
1065 	    ret (dlines);
1066 	case '\n':
1067 	    if (nlines != 0)
1068 		dlines = nlines;
1069 	    else
1070 		nlines = 1;
1071 	    ret (nlines);
1072 	case '\f':
1073 	    if (!no_intty) {
1074 		doclear ();
1075 		Fseek (f, screen_start.chrctr);
1076 		Currline = screen_start.line;
1077 		ret (dlines);
1078 	    }
1079 	    else {
1080 		write (2, &bell, 1);
1081 		break;
1082 	    }
1083 	case '\'':
1084 	    if (!no_intty) {
1085 		kill_line ();
1086 		pr ("\n***Back***\n\n");
1087 		Fseek (f, context.chrctr);
1088 		Currline = context.line;
1089 		ret (dlines);
1090 	    }
1091 	    else {
1092 		write (2, &bell, 1);
1093 		break;
1094 	    }
1095 	case '=':
1096 	    kill_line ();
1097 	    promptlen = printd (Currline);
1098 	    fflush (stdout);
1099 	    break;
1100 	case 'n':
1101 	    lastp++;
1102 	case '/':
1103 	    if (nlines == 0) nlines++;
1104 	    kill_line ();
1105 	    pr ("/");
1106 	    promptlen = 1;
1107 	    fflush (stdout);
1108 	    if (lastp) {
1109 		write (2,"\r", 1);
1110 		search (NULL, f, nlines);	/* Use previous r.e. */
1111 	    }
1112 	    else {
1113 		ttyin (cmdbuf, 78, '/');
1114 		write (2, "\r", 1);
1115 		search (cmdbuf, f, nlines);
1116 	    }
1117 	    ret (dlines-1);
1118 	case '!':
1119 	    do_shell (filename);
1120 	    break;
1121 	case '?':
1122 	case 'h':
1123 	    if ((helpf = fopen (HELPFILE, "r")) == NULL)
1124 		error ("Can't open help file");
1125 	    if (noscroll) doclear ();
1126 	    copy_file (helpf);
1127 	    fclose (helpf);
1128 	    prompt (filename);
1129 	    break;
1130 	case 'v':	/* This case should go right before default */
1131 	    if (!no_intty) {
1132 		kill_line ();
1133 		cmdbuf[0] = '+';
1134 		scanstr (Currline - dlines < 0 ? 0
1135 				: Currline - (dlines + 1) / 2, &cmdbuf[1]);
1136 		pr ("vi "); pr (cmdbuf); putchar (' '); pr (fnames[fnum]);
1137 		execute (filename, VI, "vi", cmdbuf, fnames[fnum], 0);
1138 		break;
1139 	    }
1140 	default:
1141 	    if (dum_opt) {
1142    		kill_line ();
1143 		if (Senter && Sexit) {
1144 		    tputs (Senter, 1, putch);
1145 		    promptlen = pr ("[Press 'h' for instructions.]") + (2 * soglitch);
1146 		    tputs (Sexit, 1, putch);
1147 		}
1148 		else
1149 		    promptlen = pr ("[Press 'h' for instructions.]");
1150 		fflush (stdout);
1151 	    }
1152 	    else
1153 		write (2, &bell, 1);
1154 	    break;
1155 	}
1156 	if (done) break;
1157     }
1158     putchar ('\r');
1159 endsw:
1160     inwait = 0;
1161     notell++;
1162     if (MBIT == RAW && slow_tty) {
1163 	otty.sg_flags &= ~MBIT;
1164 	stty(fileno(stderr), &otty);
1165     }
1166     return (retval);
1167 }
1168 
1169 char ch;
1170 
1171 /*
1172  * Execute a colon-prefixed command.
1173  * Returns <0 if not a command that should cause
1174  * more of the file to be printed.
1175  */
1176 
1177 colon (filename, cmd, nlines)
1178 char *filename;
1179 int cmd;
1180 int nlines;
1181 {
1182 	if (cmd == 0)
1183 		ch = readch ();
1184 	else
1185 		ch = cmd;
1186 	lastcolon = ch;
1187 	switch (ch) {
1188 	case 'f':
1189 		kill_line ();
1190 		if (!no_intty)
1191 			promptlen = printf ("\"%s\" line %d", fnames[fnum], Currline);
1192 		else
1193 			promptlen = printf ("[Not a file] line %d", Currline);
1194 		fflush (stdout);
1195 		return (-1);
1196 	case 'n':
1197 		if (nlines == 0) {
1198 			if (fnum >= nfiles - 1)
1199 				end_it ();
1200 			nlines++;
1201 		}
1202 		putchar ('\r');
1203 		erase (0);
1204 		skipf (nlines);
1205 		return (0);
1206 	case 'p':
1207 		if (no_intty) {
1208 			write (2, &bell, 1);
1209 			return (-1);
1210 		}
1211 		putchar ('\r');
1212 		erase (0);
1213 		if (nlines == 0)
1214 			nlines++;
1215 		skipf (-nlines);
1216 		return (0);
1217 	case '!':
1218 		do_shell (filename);
1219 		return (-1);
1220 	case 'q':
1221 	case 'Q':
1222 		end_it ();
1223 	default:
1224 		write (2, &bell, 1);
1225 		return (-1);
1226 	}
1227 }
1228 
1229 /*
1230 ** Read a decimal number from the terminal. Set cmd to the non-digit which
1231 ** terminates the number.
1232 */
1233 
1234 number(cmd)
1235 char *cmd;
1236 {
1237 	register int i;
1238 
1239 	i = 0; ch = otty.sg_kill;
1240 	for (;;) {
1241 		ch = readch ();
1242 		if (ch >= '0' && ch <= '9')
1243 			i = i*10 + ch - '0';
1244 		else if (ch == otty.sg_kill)
1245 			i = 0;
1246 		else {
1247 			*cmd = ch;
1248 			break;
1249 		}
1250 	}
1251 	return (i);
1252 }
1253 
1254 do_shell (filename)
1255 char *filename;
1256 {
1257 	char cmdbuf[80];
1258 
1259 	kill_line ();
1260 	pr ("!");
1261 	fflush (stdout);
1262 	promptlen = 1;
1263 	if (lastp)
1264 		pr (shell_line);
1265 	else {
1266 		ttyin (cmdbuf, 78, '!');
1267 		if (expand (shell_line, cmdbuf)) {
1268 			kill_line ();
1269 			promptlen = printf ("!%s", shell_line);
1270 		}
1271 	}
1272 	fflush (stdout);
1273 	write (2, "\n", 1);
1274 	promptlen = 0;
1275 	shellp = 1;
1276 	execute (filename, shell, shell, "-c", shell_line, 0);
1277 }
1278 
1279 /*
1280 ** Search for nth ocurrence of regular expression contained in buf in the file
1281 */
1282 
1283 search (buf, file, n)
1284 char buf[];
1285 FILE *file;
1286 register int n;
1287 {
1288     long startline = Ftell (file);
1289     register long line1 = startline;
1290     register long line2 = startline;
1291     register long line3 = startline;
1292     register int lncount;
1293     int saveln, rv, re_exec();
1294     char *s, *re_comp();
1295 
1296     context.line = saveln = Currline;
1297     context.chrctr = startline;
1298     lncount = 0;
1299     if ((s = re_comp (buf)) != 0)
1300 	error (s);
1301     while (!feof (file)) {
1302 	line3 = line2;
1303 	line2 = line1;
1304 	line1 = Ftell (file);
1305 	rdline (file);
1306 	lncount++;
1307 	if ((rv = re_exec (Line)) == 1)
1308 		if (--n == 0) {
1309 		    if (lncount > 3 || (lncount > 1 && no_intty))
1310 		    {
1311 			pr ("\n");
1312 			if (clreol)
1313 			    cleareol ();
1314 			pr("...skipping\n");
1315 		    }
1316 		    if (!no_intty) {
1317 			Currline -= (lncount >= 3 ? 3 : lncount);
1318 			Fseek (file, line3);
1319 			if (noscroll)
1320 			    if (clreol) {
1321 				home ();
1322 				cleareol ();
1323 			    }
1324 			    else
1325 				doclear ();
1326 		    }
1327 		    else {
1328 			kill_line ();
1329 			if (noscroll)
1330 			    if (clreol) {
1331 			        home ();
1332 			        cleareol ();
1333 			    }
1334 			    else
1335 				doclear ();
1336 			pr (Line);
1337 			putchar ('\n');
1338 		    }
1339 		    break;
1340 		}
1341 	else if (rv == -1)
1342 	    error ("Regular expression botch");
1343     }
1344     if (feof (file)) {
1345 	if (!no_intty) {
1346 	    file->_flag &= ~_IOEOF; /* why doesn't fseek do this ??!!??! */
1347 	    Currline = saveln;
1348 	    Fseek (file, startline);
1349 	}
1350 	else {
1351 	    pr ("\nPattern not found\n");
1352 	    end_it ();
1353 	}
1354 	error ("Pattern not found");
1355     }
1356 }
1357 
1358 execute (filename, cmd, args)
1359 char *filename;
1360 char *cmd, *args;
1361 {
1362 	int id;
1363 	int n;
1364 
1365 	fflush (stdout);
1366 	reset_tty ();
1367 	for (n = 10; (id = fork ()) < 0 && n > 0; n--)
1368 	    sleep (5);
1369 	if (id == 0) {
1370 	    if (!isatty(0)) {
1371 		close(0);
1372 		open("/dev/tty", 0);
1373 	    }
1374 	    execv (cmd, &args);
1375 	    write (2, "exec failed\n", 12);
1376 	    exit (1);
1377 	}
1378 	if (id > 0) {
1379 	    signal (SIGINT, SIG_IGN);
1380 	    signal (SIGQUIT, SIG_IGN);
1381 	    if (catch_susp)
1382 		signal(SIGTSTP, SIG_DFL);
1383 	    while (wait(0) > 0);
1384 	    signal (SIGINT, end_it);
1385 	    signal (SIGQUIT, onquit);
1386 	    if (catch_susp)
1387 		signal(SIGTSTP, onsusp);
1388 	} else
1389 	    write(2, "can't fork\n", 11);
1390 	set_tty ();
1391 	pr ("------------------------\n");
1392 	prompt (filename);
1393 }
1394 /*
1395 ** Skip n lines in the file f
1396 */
1397 
1398 skiplns (n, f)
1399 register int n;
1400 register FILE *f;
1401 {
1402     register char c;
1403 
1404     while (n > 0) {
1405 	while ((c = Getc (f)) != '\n')
1406 	    if (c == EOF)
1407 		return;
1408 	    n--;
1409 	    Currline++;
1410     }
1411 }
1412 
1413 /*
1414 ** Skip nskip files in the file list (from the command line). Nskip may be
1415 ** negative.
1416 */
1417 
1418 skipf (nskip)
1419 register int nskip;
1420 {
1421     if (nskip == 0) return;
1422     if (nskip > 0) {
1423 	if (fnum + nskip > nfiles - 1)
1424 	    nskip = nfiles - fnum - 1;
1425     }
1426     else if (within)
1427 	++fnum;
1428     fnum += nskip;
1429     if (fnum < 0)
1430 	fnum = 0;
1431     pr ("\n...Skipping ");
1432     pr ("\n");
1433     if (clreol)
1434 	cleareol ();
1435     pr ("...Skipping ");
1436     pr (nskip > 0 ? "to file " : "back to file ");
1437     pr (fnames[fnum]);
1438     pr ("\n");
1439     if (clreol)
1440 	cleareol ();
1441     pr ("\n");
1442     --fnum;
1443 }
1444 
1445 /*----------------------------- Terminal I/O -------------------------------*/
1446 
1447 initterm ()
1448 {
1449     char	buf[TBUFSIZ];
1450     static char	clearbuf[TBUFSIZ];
1451     char	*clearptr, *padstr;
1452     int		ldisc;
1453     int		lmode;
1454     char	*term;
1455     int		tgrp;
1456     struct winsize win;
1457 
1458 retry:
1459     if (!(no_tty = gtty(fileno(stdout), &otty))) {
1460 	if (ioctl(fileno(stdout), TIOCLGET, &lmode) < 0) {
1461 	    perror("TIOCLGET");
1462 	    exit(1);
1463 	}
1464 	docrterase = ((lmode & LCRTERA) != 0);
1465 	docrtkill = ((lmode & LCRTKIL) != 0);
1466 	/*
1467 	 * Wait until we're in the foreground before we save the
1468 	 * the terminal modes.
1469 	 */
1470 	if (ioctl(fileno(stdout), TIOCGPGRP, &tgrp) < 0) {
1471 	    perror("TIOCGPGRP");
1472 	    exit(1);
1473 	}
1474 	if (tgrp != getpgrp(0)) {
1475 	    kill(0, SIGTTOU);
1476 	    goto retry;
1477 	}
1478 	if ((term = getenv("TERM")) == 0 || tgetent(buf, term) <= 0) {
1479 	    dumb++; ul_opt = 0;
1480 	}
1481 	else {
1482 	    if (ioctl(fileno(stdout), TIOCGWINSZ, &win) < 0) {
1483 		Lpp = tgetnum("li");
1484 		Mcol = tgetnum("co");
1485 	    } else {
1486 		if ((Lpp = win.ws_row) == 0)
1487 		    Lpp = tgetnum("li");
1488 		if ((Mcol = win.ws_col) == 0)
1489 		    Mcol = tgetnum("co");
1490 	    }
1491 	    if ((Lpp <= 0) || tgetflag("hc")) {
1492 		hard++;	/* Hard copy terminal */
1493 		Lpp = 24;
1494 	    }
1495 	    if (tgetflag("xn"))
1496 		eatnl++; /* Eat newline at last column + 1; dec, concept */
1497 	    if (Mcol <= 0)
1498 		Mcol = 80;
1499 
1500 	    if (tailequ (fnames[0], "page") || !hard && tgetflag("ns"))
1501 		noscroll++;
1502 	    Wrap = tgetflag("am");
1503 	    bad_so = tgetflag ("xs");
1504 	    clearptr = clearbuf;
1505 	    eraseln = tgetstr("ce",&clearptr);
1506 	    Clear = tgetstr("cl", &clearptr);
1507 	    Senter = tgetstr("so", &clearptr);
1508 	    Sexit = tgetstr("se", &clearptr);
1509 	    if ((soglitch = tgetnum("sg")) < 0)
1510 		soglitch = 0;
1511 
1512 	    /*
1513 	     *  Set up for underlining:  some terminals don't need it;
1514 	     *  others have start/stop sequences, still others have an
1515 	     *  underline char sequence which is assumed to move the
1516 	     *  cursor forward one character.  If underline sequence
1517 	     *  isn't available, settle for standout sequence.
1518 	     */
1519 
1520 	    if (tgetflag("ul") || tgetflag("os"))
1521 		ul_opt = 0;
1522 	    if ((chUL = tgetstr("uc", &clearptr)) == NULL )
1523 		chUL = "";
1524 	    if (((ULenter = tgetstr("us", &clearptr)) == NULL ||
1525 	         (ULexit = tgetstr("ue", &clearptr)) == NULL) && !*chUL) {
1526 	        if ((ULenter = Senter) == NULL || (ULexit = Sexit) == NULL) {
1527 			ULenter = "";
1528 			ULexit = "";
1529 		} else
1530 			ulglitch = soglitch;
1531 	    } else {
1532 		if ((ulglitch = tgetnum("ug")) < 0)
1533 		    ulglitch = 0;
1534 	    }
1535 
1536 	    if (padstr = tgetstr("pc", &clearptr))
1537 		PC = *padstr;
1538 	    Home = tgetstr("ho",&clearptr);
1539 	    if (Home == 0 || *Home == '\0')
1540 	    {
1541 		if ((cursorm = tgetstr("cm", &clearptr)) != NULL) {
1542 		    strcpy(cursorhome, tgoto(cursorm, 0, 0));
1543 		    Home = cursorhome;
1544 	       }
1545 	    }
1546 	    EodClr = tgetstr("cd", &clearptr);
1547 	    if ((chBS = tgetstr("bc", &clearptr)) == NULL)
1548 		chBS = "\b";
1549 
1550 	}
1551 	if ((shell = getenv("SHELL")) == NULL)
1552 	    shell = "/bin/sh";
1553     }
1554     no_intty = gtty(fileno(stdin), &otty);
1555     gtty(fileno(stderr), &otty);
1556     savetty = otty;
1557     ospeed = otty.sg_ospeed;
1558     slow_tty = ospeed < B1200;
1559     hardtabs = (otty.sg_flags & TBDELAY) != XTABS;
1560     if (!no_tty) {
1561 	otty.sg_flags &= ~ECHO;
1562 	if (MBIT == CBREAK || !slow_tty)
1563 	    otty.sg_flags |= MBIT;
1564     }
1565 }
1566 
1567 readch ()
1568 {
1569 	char ch;
1570 	extern int errno;
1571 
1572 	errno = 0;
1573 	if (read (2, &ch, 1) <= 0)
1574 		if (errno != EINTR)
1575 			end_it();
1576 		else
1577 			ch = otty.sg_kill;
1578 	return (ch);
1579 }
1580 
1581 static char BS = '\b';
1582 static char *BSB = "\b \b";
1583 static char CARAT = '^';
1584 #define ERASEONECHAR \
1585     if (docrterase) \
1586 	write (2, BSB, sizeof(BSB)); \
1587     else \
1588 	write (2, &BS, sizeof(BS));
1589 
1590 ttyin (buf, nmax, pchar)
1591 char buf[];
1592 register int nmax;
1593 char pchar;
1594 {
1595     register char *sptr;
1596     register char ch;
1597     register int slash = 0;
1598     int	maxlen;
1599     char cbuf;
1600 
1601     sptr = buf;
1602     maxlen = 0;
1603     while (sptr - buf < nmax) {
1604 	if (promptlen > maxlen) maxlen = promptlen;
1605 	ch = readch ();
1606 	if (ch == '\\') {
1607 	    slash++;
1608 	}
1609 	else if ((ch == otty.sg_erase) && !slash) {
1610 	    if (sptr > buf) {
1611 		--promptlen;
1612 		ERASEONECHAR
1613 		--sptr;
1614 		if ((*sptr < ' ' && *sptr != '\n') || *sptr == RUBOUT) {
1615 		    --promptlen;
1616 		    ERASEONECHAR
1617 		}
1618 		continue;
1619 	    }
1620 	    else {
1621 		if (!eraseln) promptlen = maxlen;
1622 		longjmp (restore, 1);
1623 	    }
1624 	}
1625 	else if ((ch == otty.sg_kill) && !slash) {
1626 	    if (hard) {
1627 		show (ch);
1628 		putchar ('\n');
1629 		putchar (pchar);
1630 	    }
1631 	    else {
1632 		putchar ('\r');
1633 		putchar (pchar);
1634 		if (eraseln)
1635 		    erase (1);
1636 		else if (docrtkill)
1637 		    while (promptlen-- > 1)
1638 			write (2, BSB, sizeof(BSB));
1639 		promptlen = 1;
1640 	    }
1641 	    sptr = buf;
1642 	    fflush (stdout);
1643 	    continue;
1644 	}
1645 	if (slash && (ch == otty.sg_kill || ch == otty.sg_erase)) {
1646 	    ERASEONECHAR
1647 	    --sptr;
1648 	}
1649 	if (ch != '\\')
1650 	    slash = 0;
1651 	*sptr++ = ch;
1652 	if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1653 	    ch += ch == RUBOUT ? -0100 : 0100;
1654 	    write (2, &CARAT, 1);
1655 	    promptlen++;
1656 	}
1657 	cbuf = ch;
1658 	if (ch != '\n' && ch != ESC) {
1659 	    write (2, &cbuf, 1);
1660 	    promptlen++;
1661 	}
1662 	else
1663 	    break;
1664     }
1665     *--sptr = '\0';
1666     if (!eraseln) promptlen = maxlen;
1667     if (sptr - buf >= nmax - 1)
1668 	error ("Line too long");
1669 }
1670 
1671 expand (outbuf, inbuf)
1672 char *outbuf;
1673 char *inbuf;
1674 {
1675     register char *instr;
1676     register char *outstr;
1677     register char ch;
1678     char temp[200];
1679     int changed = 0;
1680 
1681     instr = inbuf;
1682     outstr = temp;
1683     while ((ch = *instr++) != '\0')
1684 	switch (ch) {
1685 	case '%':
1686 	    if (!no_intty) {
1687 		strcpy (outstr, fnames[fnum]);
1688 		outstr += strlen (fnames[fnum]);
1689 		changed++;
1690 	    }
1691 	    else
1692 		*outstr++ = ch;
1693 	    break;
1694 	case '!':
1695 	    if (!shellp)
1696 		error ("No previous command to substitute for");
1697 	    strcpy (outstr, shell_line);
1698 	    outstr += strlen (shell_line);
1699 	    changed++;
1700 	    break;
1701 	case '\\':
1702 	    if (*instr == '%' || *instr == '!') {
1703 		*outstr++ = *instr++;
1704 		break;
1705 	    }
1706 	default:
1707 	    *outstr++ = ch;
1708 	}
1709     *outstr++ = '\0';
1710     strcpy (outbuf, temp);
1711     return (changed);
1712 }
1713 
1714 show (ch)
1715 register char ch;
1716 {
1717     char cbuf;
1718 
1719     if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1720 	ch += ch == RUBOUT ? -0100 : 0100;
1721 	write (2, &CARAT, 1);
1722 	promptlen++;
1723     }
1724     cbuf = ch;
1725     write (2, &cbuf, 1);
1726     promptlen++;
1727 }
1728 
1729 error (mess)
1730 char *mess;
1731 {
1732     if (clreol)
1733 	cleareol ();
1734     else
1735 	kill_line ();
1736     promptlen += strlen (mess);
1737     if (Senter && Sexit) {
1738 	tputs (Senter, 1, putch);
1739 	pr(mess);
1740 	tputs (Sexit, 1, putch);
1741     }
1742     else
1743 	pr (mess);
1744     fflush(stdout);
1745     errors++;
1746     longjmp (restore, 1);
1747 }
1748 
1749 
1750 set_tty ()
1751 {
1752 	otty.sg_flags |= MBIT;
1753 	otty.sg_flags &= ~ECHO;
1754 	stty(fileno(stderr), &otty);
1755 }
1756 
1757 reset_tty ()
1758 {
1759     if (no_tty)
1760 	return;
1761     if (pstate) {
1762 	tputs(ULexit, 1, putch);
1763 	fflush(stdout);
1764 	pstate = 0;
1765     }
1766     otty.sg_flags |= ECHO;
1767     otty.sg_flags &= ~MBIT;
1768     stty(fileno(stderr), &savetty);
1769 }
1770 
1771 rdline (f)
1772 register FILE *f;
1773 {
1774     register char c;
1775     register char *p;
1776 
1777     p = Line;
1778     while ((c = Getc (f)) != '\n' && c != EOF && p - Line < LINSIZ - 1)
1779 	*p++ = c;
1780     if (c == '\n')
1781 	Currline++;
1782     *p = '\0';
1783 }
1784 
1785 /* Come here when we get a suspend signal from the terminal */
1786 
1787 onsusp ()
1788 {
1789     /* ignore SIGTTOU so we don't get stopped if csh grabs the tty */
1790     signal(SIGTTOU, SIG_IGN);
1791     reset_tty ();
1792     fflush (stdout);
1793     signal(SIGTTOU, SIG_DFL);
1794     /* Send the TSTP signal to suspend our process group */
1795     signal(SIGTSTP, SIG_DFL);
1796     sigsetmask(0);
1797     kill (0, SIGTSTP);
1798     /* Pause for station break */
1799 
1800     /* We're back */
1801     signal (SIGTSTP, onsusp);
1802     set_tty ();
1803     if (inwait)
1804 	    longjmp (restore);
1805 }
1806