xref: /csrg-svn/old/more/more.c (revision 27006)
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	5.4 (Berkeley) 04/03/86";
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 
35 #define HELPFILE	"/usr/lib/more.help"
36 #define VI		"/usr/ucb/vi"
37 
38 #define Fopen(s,m)	(Currline = 0,file_pos=0,fopen(s,m))
39 #define Ftell(f)	file_pos
40 #define Fseek(f,off)	(file_pos=off,fseek(f,off,0))
41 #define Getc(f)		(++file_pos, getc(f))
42 #define Ungetc(c,f)	(--file_pos, ungetc(c,f))
43 
44 #define MBIT	CBREAK
45 #define stty(fd,argp)	ioctl(fd,TIOCSETN,argp)
46 
47 #define TBUFSIZ	1024
48 #define LINSIZ	256
49 #define ctrl(letter)	('letter' & 077)
50 #define RUBOUT	'\177'
51 #define ESC	'\033'
52 #define QUIT	'\034'
53 
54 struct sgttyb	otty, savetty;
55 long		file_pos, file_size;
56 int		fnum, no_intty, no_tty, slow_tty;
57 int		dum_opt, dlines, onquit(), end_it(), chgwinsz();
58 int		onsusp();
59 int		nscroll = 11;	/* Number of lines scrolled by 'd' */
60 int		fold_opt = 1;	/* Fold long lines */
61 int		stop_opt = 1;	/* Stop after form feeds */
62 int		ssp_opt = 0;	/* Suppress white space */
63 int		ul_opt = 1;	/* Underline as best we can */
64 int		promptlen;
65 int		Currline;	/* Line we are currently at */
66 int		startup = 1;
67 int		firstf = 1;
68 int		notell = 1;
69 int		docrterase = 0;
70 int		docrtkill = 0;
71 int		bad_so;	/* True if overwriting does not turn off standout */
72 int		inwait, Pause, errors;
73 int		within;	/* true if we are within a file,
74 			false if we are between files */
75 int		hard, dumb, noscroll, hardtabs, clreol;
76 int		catch_susp;	/* We should catch the SIGTSTP signal */
77 char		**fnames;	/* The list of file names */
78 int		nfiles;		/* Number of files left to process */
79 char		*shell;		/* The name of the shell to use */
80 int		shellp;		/* A previous shell command exists */
81 char		ch;
82 jmp_buf		restore;
83 char		Line[LINSIZ];	/* Line buffer */
84 int		Lpp = 24;	/* lines per page */
85 char		*Clear;		/* clear screen */
86 char		*eraseln;	/* erase line */
87 char		*Senter, *Sexit;/* enter and exit standout mode */
88 char		*ULenter, *ULexit;	/* enter and exit underline mode */
89 char		*chUL;		/* underline character */
90 char		*chBS;		/* backspace character */
91 char		*Home;		/* go to home */
92 char		*cursorm;	/* cursor movement */
93 char		cursorhome[40];	/* contains cursor movement to home */
94 char		*EodClr;	/* clear rest of screen */
95 char		*tgetstr();
96 int		Mcol = 80;	/* number of columns */
97 int		Wrap = 1;	/* set if automargins */
98 int		soglitch;	/* terminal has standout mode glitch */
99 int		ulglitch;	/* terminal has underline mode glitch */
100 int		pstate = 0;	/* current UL state */
101 long		fseek();
102 char		*getenv();
103 struct {
104     long chrctr, line;
105 } context, screen_start;
106 extern char	PC;		/* pad character */
107 extern short	ospeed;
108 
109 
110 main(argc, argv)
111 int argc;
112 char *argv[];
113 {
114     register FILE	*f;
115     register char	*s;
116     register char	*p;
117     register char	ch;
118     register int	left;
119     int			prnames = 0;
120     int			initopt = 0;
121     int			srchopt = 0;
122     int			clearit = 0;
123     int			initline;
124     char		initbuf[80];
125     FILE		*checkf();
126 
127     nfiles = argc;
128     fnames = argv;
129     initterm ();
130     nscroll = Lpp/2 - 1;
131     if (nscroll <= 0)
132 	nscroll = 1;
133     if(s = getenv("MORE")) argscan(s);
134     while (--nfiles > 0) {
135 	if ((ch = (*++fnames)[0]) == '-') {
136 	    argscan(*fnames+1);
137 	}
138 	else if (ch == '+') {
139 	    s = *fnames;
140 	    if (*++s == '/') {
141 		srchopt++;
142 		for (++s, p = initbuf; p < initbuf + 79 && *s != '\0';)
143 		    *p++ = *s++;
144 		*p = '\0';
145 	    }
146 	    else {
147 		initopt++;
148 		for (initline = 0; *s != '\0'; s++)
149 		    if (isdigit (*s))
150 			initline = initline*10 + *s -'0';
151 		--initline;
152 	    }
153 	}
154 	else break;
155     }
156     /* allow clreol only if Home and eraseln and EodClr strings are
157      *  defined, and in that case, make sure we are in noscroll mode
158      */
159     if(clreol)
160     {
161         if((Home == NULL) || (*Home == '\0') ||
162 	   (eraseln == NULL) || (*eraseln == '\0') ||
163            (EodClr == NULL) || (*EodClr == '\0') )
164 	      clreol = 0;
165 	else noscroll = 1;
166     }
167     if (dlines == 0)
168 	dlines = Lpp - (noscroll ? 1 : 2);
169     left = dlines;
170     if (nfiles > 1)
171 	prnames++;
172     if (!no_intty && nfiles == 0) {
173 	fputs("Usage: ",stderr);
174 	fputs(argv[0],stderr);
175 	fputs(" [-dfln] [+linenum | +/pattern] name1 name2 ...\n",stderr);
176 	exit(1);
177     }
178     else
179 	f = stdin;
180     if (!no_tty) {
181 	signal(SIGQUIT, onquit);
182 	signal(SIGINT, end_it);
183 	signal(SIGWINCH, chgwinsz);
184 	if (signal (SIGTSTP, SIG_IGN) == SIG_DFL) {
185 	    signal(SIGTSTP, onsusp);
186 	    catch_susp++;
187 	}
188 	stty (fileno(stderr), &otty);
189     }
190     if (no_intty) {
191 	if (no_tty)
192 	    copy_file (stdin);
193 	else {
194 	    if ((ch = Getc (f)) == '\f')
195 		doclear();
196 	    else {
197 		Ungetc (ch, f);
198 		if (noscroll && (ch != EOF)) {
199 		    if (clreol)
200 			home ();
201 		    else
202 			doclear ();
203 		}
204 	    }
205 	    if (srchopt)
206 	    {
207 		search (initbuf, stdin, 1);
208 		if (noscroll)
209 		    left--;
210 	    }
211 	    else if (initopt)
212 		skiplns (initline, stdin);
213 	    screen (stdin, left);
214 	}
215 	no_intty = 0;
216 	prnames++;
217 	firstf = 0;
218     }
219 
220     while (fnum < nfiles) {
221 	if ((f = checkf (fnames[fnum], &clearit)) != NULL) {
222 	    context.line = context.chrctr = 0;
223 	    Currline = 0;
224 	    if (firstf) setjmp (restore);
225 	    if (firstf) {
226 		firstf = 0;
227 		if (srchopt)
228 		{
229 		    search (initbuf, f, 1);
230 		    if (noscroll)
231 			left--;
232 		}
233 		else if (initopt)
234 		    skiplns (initline, f);
235 	    }
236 	    else if (fnum < nfiles && !no_tty) {
237 		setjmp (restore);
238 		left = command (fnames[fnum], f);
239 	    }
240 	    if (left != 0) {
241 		if ((noscroll || clearit) && (file_size != 0x7fffffffffffffffL))
242 		    if (clreol)
243 			home ();
244 		    else
245 			doclear ();
246 		if (prnames) {
247 		    if (bad_so)
248 			erase (0);
249 		    if (clreol)
250 			cleareol ();
251 		    pr("::::::::::::::");
252 		    if (promptlen > 14)
253 			erase (14);
254 		    printf ("\n");
255 		    if(clreol) cleareol();
256 		    printf("%s\n", fnames[fnum]);
257 		    if(clreol) cleareol();
258 		    printf("::::::::::::::\n", fnames[fnum]);
259 		    if (left > Lpp - 4)
260 			left = Lpp - 4;
261 		}
262 		if (no_tty)
263 		    copy_file (f);
264 		else {
265 		    within++;
266 		    screen(f, left);
267 		    within = 0;
268 		}
269 	    }
270 	    setjmp (restore);
271 	    fflush(stdout);
272 	    fclose(f);
273 	    screen_start.line = screen_start.chrctr = 0L;
274 	    context.line = context.chrctr = 0L;
275 	}
276 	fnum++;
277 	firstf = 0;
278     }
279     reset_tty ();
280     exit(0);
281 }
282 
283 argscan(s)
284 char *s;
285 {
286 	for (dlines = 0; *s != '\0'; s++)
287 	{
288 		switch (*s)
289 		{
290 		  case '0': case '1': case '2':
291 		  case '3': case '4': case '5':
292 		  case '6': case '7': case '8':
293 		  case '9':
294 			dlines = dlines*10 + *s - '0';
295 			break;
296 		  case 'd':
297 			dum_opt = 1;
298 			break;
299 		  case 'l':
300 			stop_opt = 0;
301 			break;
302 		  case 'f':
303 			fold_opt = 0;
304 			break;
305 		  case 'p':
306 			noscroll++;
307 			break;
308 		  case 'c':
309 			clreol++;
310 			break;
311 		  case 's':
312 			ssp_opt = 1;
313 			break;
314 		  case 'u':
315 			ul_opt = 0;
316 			break;
317 		}
318 	}
319 }
320 
321 
322 /*
323 ** Check whether the file named by fs is an ASCII file which the user may
324 ** access.  If it is, return the opened file. Otherwise return NULL.
325 */
326 
327 FILE *
328 checkf (fs, clearfirst)
329 register char *fs;
330 int *clearfirst;
331 {
332     struct stat stbuf;
333     register FILE *f;
334     char c;
335 
336     if (stat (fs, &stbuf) == -1) {
337 	fflush(stdout);
338 	if (clreol)
339 	    cleareol ();
340 	perror(fs);
341 	return (NULL);
342     }
343     if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
344 	printf("\n*** %s: directory ***\n\n", fs);
345 	return (NULL);
346     }
347     if ((f=Fopen(fs, "r")) == NULL) {
348 	fflush(stdout);
349 	perror(fs);
350 	return (NULL);
351     }
352     c = Getc(f);
353 
354     /* Try to see whether it is an ASCII file */
355 
356     switch ((c | *f->_ptr << 8) & 0177777) {
357     case 0405:
358     case 0407:
359     case 0410:
360     case 0411:
361     case 0413:
362     case 0177545:
363 	printf("\n******** %s: Not a text file ********\n\n", fs);
364 	fclose (f);
365 	return (NULL);
366     default:
367 	break;
368     }
369     if (c == '\f')
370 	*clearfirst = 1;
371     else {
372 	*clearfirst = 0;
373 	Ungetc (c, f);
374     }
375     if ((file_size = stbuf.st_size) == 0)
376 	file_size = 0x7fffffffffffffffL;
377     return (f);
378 }
379 
380 /*
381 ** A real function, for the tputs routine in termlib
382 */
383 
384 putch (ch)
385 char ch;
386 {
387     putchar (ch);
388 }
389 
390 /*
391 ** Print out the contents of the file f, one screenful at a time.
392 */
393 
394 #define STOP -10
395 
396 screen (f, num_lines)
397 register FILE *f;
398 register int num_lines;
399 {
400     register int c;
401     register int nchars;
402     int length;			/* length of current line */
403     static int prev_len = 1;	/* length of previous line */
404 
405     for (;;) {
406 	while (num_lines > 0 && !Pause) {
407 	    if ((nchars = getline (f, &length)) == EOF)
408 	    {
409 		if (clreol)
410 		    clreos();
411 		return;
412 	    }
413 	    if (ssp_opt && length == 0 && prev_len == 0)
414 		continue;
415 	    prev_len = length;
416 	    if (bad_so || (Senter && *Senter == ' ') && promptlen > 0)
417 		erase (0);
418 	    /* must clear before drawing line since tabs on some terminals
419 	     * do not erase what they tab over.
420 	     */
421 	    if (clreol)
422 		cleareol ();
423 	    prbuf (Line, length);
424 	    if (nchars < promptlen)
425 		erase (nchars);	/* erase () sets promptlen to 0 */
426 	    else promptlen = 0;
427 	    /* is this needed?
428 	     * if (clreol)
429 	     *	cleareol();	/* must clear again in case we wrapped *
430 	     */
431 	    if (nchars < Mcol || !fold_opt)
432 		prbuf("\n", 1);	/* will turn off UL if necessary */
433 	    if (nchars == STOP)
434 		break;
435 	    num_lines--;
436 	}
437 	if (pstate) {
438 		tputs(ULexit, 1, putch);
439 		pstate = 0;
440 	}
441 	fflush(stdout);
442 	if ((c = Getc(f)) == EOF)
443 	{
444 	    if (clreol)
445 		clreos ();
446 	    return;
447 	}
448 
449 	if (Pause && clreol)
450 	    clreos ();
451 	Ungetc (c, f);
452 	setjmp (restore);
453 	Pause = 0; startup = 0;
454 	if ((num_lines = command (NULL, f)) == 0)
455 	    return;
456 	if (hard && promptlen > 0)
457 		erase (0);
458 	if (noscroll && num_lines >= dlines)
459 	{
460 	    if (clreol)
461 		home();
462 	    else
463 		doclear ();
464 	}
465 	screen_start.line = Currline;
466 	screen_start.chrctr = Ftell (f);
467     }
468 }
469 
470 /*
471 ** Come here if a quit signal is received
472 */
473 
474 onquit()
475 {
476     signal(SIGQUIT, SIG_IGN);
477     if (!inwait) {
478 	putchar ('\n');
479 	if (!startup) {
480 	    signal(SIGQUIT, onquit);
481 	    longjmp (restore, 1);
482 	}
483 	else
484 	    Pause++;
485     }
486     else if (!dum_opt && notell) {
487 	write (2, "[Use q or Q to quit]", 20);
488 	promptlen += 20;
489 	notell = 0;
490     }
491     signal(SIGQUIT, onquit);
492 }
493 
494 /*
495 ** Come here if a signal for a window size change is received
496 */
497 
498 chgwinsz()
499 {
500     struct winsize win;
501 
502     (void) signal(SIGWINCH, SIG_IGN);
503     if (ioctl(fileno(stdout), TIOCGWINSZ, &win) != -1) {
504 	if (win.ws_row != 0) {
505 	    Lpp = win.ws_row;
506 	    nscroll = Lpp/2 - 1;
507 	    if (nscroll <= 0)
508 		nscroll = 1;
509 	    dlines = Lpp - (noscroll ? 1 : 2);
510 	}
511 	if (win.ws_col != 0)
512 	    Mcol = win.ws_col;
513     }
514     (void) signal(SIGWINCH, chgwinsz);
515 }
516 
517 /*
518 ** Clean up terminal state and exit. Also come here if interrupt signal received
519 */
520 
521 end_it ()
522 {
523 
524     reset_tty ();
525     if (clreol) {
526 	putchar ('\r');
527 	clreos ();
528 	fflush (stdout);
529     }
530     else if (!clreol && (promptlen > 0)) {
531 	kill_line ();
532 	fflush (stdout);
533     }
534     else
535 	write (2, "\n", 1);
536     _exit(0);
537 }
538 
539 copy_file(f)
540 register FILE *f;
541 {
542     register int c;
543 
544     while ((c = getc(f)) != EOF)
545 	putchar(c);
546 }
547 
548 /* Simplified printf function */
549 
550 printf (fmt, args)
551 register char *fmt;
552 int args;
553 {
554 	register int *argp;
555 	register char ch;
556 	register int ccount;
557 
558 	ccount = 0;
559 	argp = &args;
560 	while (*fmt) {
561 		while ((ch = *fmt++) != '%') {
562 			if (ch == '\0')
563 				return (ccount);
564 			ccount++;
565 			putchar (ch);
566 		}
567 		switch (*fmt++) {
568 		case 'd':
569 			ccount += printd (*argp);
570 			break;
571 		case 's':
572 			ccount += pr ((char *)*argp);
573 			break;
574 		case '%':
575 			ccount++;
576 			argp--;
577 			putchar ('%');
578 			break;
579 		case '0':
580 			return (ccount);
581 		default:
582 			break;
583 		}
584 		++argp;
585 	}
586 	return (ccount);
587 
588 }
589 
590 /*
591 ** Print an integer as a string of decimal digits,
592 ** returning the length of the print representation.
593 */
594 
595 printd (n)
596 int n;
597 {
598     int a, nchars;
599 
600     if (a = n/10)
601 	nchars = 1 + printd(a);
602     else
603 	nchars = 1;
604     putchar (n % 10 + '0');
605     return (nchars);
606 }
607 
608 /* Put the print representation of an integer into a string */
609 static char *sptr;
610 
611 scanstr (n, str)
612 int n;
613 char *str;
614 {
615     sptr = str;
616     Sprintf (n);
617     *sptr = '\0';
618 }
619 
620 Sprintf (n)
621 {
622     int a;
623 
624     if (a = n/10)
625 	Sprintf (a);
626     *sptr++ = n % 10 + '0';
627 }
628 
629 static char bell = ctrl(G);
630 
631 strlen (s)
632 char *s;
633 {
634     register char *p;
635 
636     p = s;
637     while (*p++)
638 	;
639     return (p - s - 1);
640 }
641 
642 /* See whether the last component of the path name "path" is equal to the
643 ** string "string"
644 */
645 
646 tailequ (path, string)
647 char *path;
648 register char *string;
649 {
650 	register char *tail;
651 
652 	tail = path + strlen(path);
653 	while (tail >= path)
654 		if (*(--tail) == '/')
655 			break;
656 	++tail;
657 	while (*tail++ == *string++)
658 		if (*tail == '\0')
659 			return(1);
660 	return(0);
661 }
662 
663 prompt (filename)
664 char *filename;
665 {
666     if (clreol)
667 	cleareol ();
668     else if (promptlen > 0)
669 	kill_line ();
670     if (!hard) {
671 	promptlen = 8;
672 	if (Senter && Sexit) {
673 	    tputs (Senter, 1, putch);
674 	    promptlen += (2 * soglitch);
675 	}
676 	if (clreol)
677 	    cleareol ();
678 	pr("--More--");
679 	if (filename != NULL) {
680 	    promptlen += printf ("(Next file: %s)", filename);
681 	}
682 	else if (!no_intty) {
683 	    promptlen += printf ("(%d%%)", (int)((file_pos * 100) / file_size));
684 	}
685 	if (dum_opt) {
686 	    promptlen += pr("[Press space to continue, 'q' to quit.]");
687 	}
688 	if (Senter && Sexit)
689 	    tputs (Sexit, 1, putch);
690 	if (clreol)
691 	    clreos ();
692 	fflush(stdout);
693     }
694     else
695 	write (2, &bell, 1);
696     inwait++;
697 }
698 
699 /*
700 ** Get a logical line
701 */
702 
703 getline(f, length)
704 register FILE *f;
705 int *length;
706 {
707     register int	c;
708     register char	*p;
709     register int	column;
710     static int		colflg;
711 
712     p = Line;
713     column = 0;
714     c = Getc (f);
715     if (colflg && c == '\n') {
716 	Currline++;
717 	c = Getc (f);
718     }
719     while (p < &Line[LINSIZ - 1]) {
720 	if (c == EOF) {
721 	    if (p > Line) {
722 		*p = '\0';
723 		*length = p - Line;
724 		return (column);
725 	    }
726 	    *length = p - Line;
727 	    return (EOF);
728 	}
729 	if (c == '\n') {
730 	    Currline++;
731 	    break;
732 	}
733 	*p++ = c;
734 	if (c == '\t')
735 	    if (hardtabs && column < promptlen && !hard) {
736 		if (eraseln && !dumb) {
737 		    column = 1 + (column | 7);
738 		    tputs (eraseln, 1, putch);
739 		    promptlen = 0;
740 		}
741 		else {
742 		    for (--p; column & 7 && p < &Line[LINSIZ - 1]; column++) {
743 			*p++ = ' ';
744 		    }
745 		    if (column >= promptlen) promptlen = 0;
746 		}
747 	    }
748 	    else
749 		column = 1 + (column | 7);
750 	else if (c == '\b' && column > 0)
751 	    column--;
752 	else if (c == '\r')
753 	    column = 0;
754 	else if (c == '\f' && stop_opt) {
755 		p[-1] = '^';
756 		*p++ = 'L';
757 		column += 2;
758 		Pause++;
759 	}
760 	else if (c == EOF) {
761 	    *length = p - Line;
762 	    return (column);
763 	}
764 	else if (c >= ' ' && c != RUBOUT)
765 	    column++;
766 	if (column >= Mcol && fold_opt) break;
767 	c = Getc (f);
768     }
769     if (column >= Mcol && Mcol > 0) {
770 	if (!Wrap) {
771 	    *p++ = '\n';
772 	}
773     }
774     colflg = column == Mcol && fold_opt;
775     *length = p - Line;
776     *p = 0;
777     return (column);
778 }
779 
780 /*
781 ** Erase the rest of the prompt, assuming we are starting at column col.
782 */
783 
784 erase (col)
785 register int col;
786 {
787 
788     if (promptlen == 0)
789 	return;
790     if (hard) {
791 	putchar ('\n');
792     }
793     else {
794 	if (col == 0)
795 	    putchar ('\r');
796 	if (!dumb && eraseln)
797 	    tputs (eraseln, 1, putch);
798 	else
799 	    for (col = promptlen - col; col > 0; col--)
800 		putchar (' ');
801     }
802     promptlen = 0;
803 }
804 
805 /*
806 ** Erase the current line entirely
807 */
808 
809 kill_line ()
810 {
811     erase (0);
812     if (!eraseln || dumb) putchar ('\r');
813 }
814 
815 /*
816  * force clear to end of line
817  */
818 cleareol()
819 {
820     tputs(eraseln, 1, putch);
821 }
822 
823 clreos()
824 {
825     tputs(EodClr, 1, putch);
826 }
827 
828 /*
829 **  Print string and return number of characters
830 */
831 
832 pr(s1)
833 char	*s1;
834 {
835     register char	*s;
836     register char	c;
837 
838     for (s = s1; c = *s++; )
839 	putchar(c);
840     return (s - s1 - 1);
841 }
842 
843 
844 /* Print a buffer of n characters */
845 
846 prbuf (s, n)
847 register char *s;
848 register int n;
849 {
850     register char c;			/* next output character */
851     register int state;			/* next output char's UL state */
852 #define wouldul(s,n)	((n) >= 2 && (((s)[0] == '_' && (s)[1] == '\b') || ((s)[1] == '\b' && (s)[2] == '_')))
853 
854     while (--n >= 0)
855 	if (!ul_opt)
856 	    putchar (*s++);
857 	else {
858 	    if (*s == ' ' && pstate == 0 && ulglitch && wouldul(s+1, n-1)) {
859 		s++;
860 		continue;
861 	    }
862 	    if (state = wouldul(s, n)) {
863 		c = (*s == '_')? s[2] : *s ;
864 		n -= 2;
865 		s += 3;
866 	    } else
867 		c = *s++;
868 	    if (state != pstate) {
869 		if (c == ' ' && state == 0 && ulglitch && wouldul(s, n-1))
870 		    state = 1;
871 		else
872 		    tputs(state ? ULenter : ULexit, 1, putch);
873 	    }
874 	    if (c != ' ' || pstate == 0 || state != 0 || ulglitch == 0)
875 	        putchar(c);
876 	    if (state && *chUL) {
877 		pr(chBS);
878 		tputs(chUL, 1, putch);
879 	    }
880 	    pstate = state;
881 	}
882 }
883 
884 /*
885 **  Clear the screen
886 */
887 
888 doclear()
889 {
890     if (Clear && !hard) {
891 	tputs(Clear, 1, putch);
892 
893 	/* Put out carriage return so that system doesn't
894 	** get confused by escape sequences when expanding tabs
895 	*/
896 	putchar ('\r');
897 	promptlen = 0;
898     }
899 }
900 
901 /*
902  * Go to home position
903  */
904 home()
905 {
906     tputs(Home,1,putch);
907 }
908 
909 static int lastcmd, lastarg, lastp;
910 static int lastcolon;
911 char shell_line[132];
912 
913 /*
914 ** Read a command and do it. A command consists of an optional integer
915 ** argument followed by the command character.  Return the number of lines
916 ** to display in the next screenful.  If there is nothing more to display
917 ** in the current file, zero is returned.
918 */
919 
920 command (filename, f)
921 char *filename;
922 register FILE *f;
923 {
924     register int nlines;
925     register int retval;
926     register char c;
927     char colonch;
928     FILE *helpf;
929     int done;
930     char comchar, cmdbuf[80], *p;
931 
932 #define ret(val) retval=val;done++;break
933 
934     done = 0;
935     if (!errors)
936 	prompt (filename);
937     else
938 	errors = 0;
939     if (MBIT == RAW && slow_tty) {
940 	otty.sg_flags |= MBIT;
941 	stty(fileno(stderr), &otty);
942     }
943     for (;;) {
944 	nlines = number (&comchar);
945 	lastp = colonch = 0;
946 	if (comchar == '.') {	/* Repeat last command */
947 		lastp++;
948 		comchar = lastcmd;
949 		nlines = lastarg;
950 		if (lastcmd == ':')
951 			colonch = lastcolon;
952 	}
953 	lastcmd = comchar;
954 	lastarg = nlines;
955 	if (comchar == otty.sg_erase) {
956 	    kill_line ();
957 	    prompt (filename);
958 	    continue;
959 	}
960 	switch (comchar) {
961 	case ':':
962 	    retval = colon (filename, colonch, nlines);
963 	    if (retval >= 0)
964 		done++;
965 	    break;
966 	case 'b':
967 	case ctrl(B):
968 	    {
969 		register int initline;
970 
971 		if (no_intty) {
972 		    write(2, &bell, 1);
973 		    return (-1);
974 		}
975 
976 		if (nlines == 0) nlines++;
977 
978 		putchar ('\r');
979 		erase (0);
980 		printf ("\n");
981 		if (clreol)
982 			cleareol ();
983 		printf ("...back %d page", nlines);
984 		if (nlines > 1)
985 			pr ("s\n");
986 		else
987 			pr ("\n");
988 
989 		if (clreol)
990 			cleareol ();
991 		pr ("\n");
992 
993 		initline = Currline - dlines * (nlines + 1);
994 		if (! noscroll)
995 		    --initline;
996 		if (initline < 0) initline = 0;
997 		Fseek(f, 0L);
998 		Currline = 0;	/* skiplns() will make Currline correct */
999 		skiplns(initline, f);
1000 		if (! noscroll) {
1001 		    ret(dlines + 1);
1002 		}
1003 		else {
1004 		    ret(dlines);
1005 		}
1006 	    }
1007 	case ' ':
1008 	case 'z':
1009 	    if (nlines == 0) nlines = dlines;
1010 	    else if (comchar == 'z') dlines = nlines;
1011 	    ret (nlines);
1012 	case 'd':
1013 	case ctrl(D):
1014 	    if (nlines != 0) nscroll = nlines;
1015 	    ret (nscroll);
1016 	case 'q':
1017 	case 'Q':
1018 	    end_it ();
1019 	case 's':
1020 	case 'f':
1021 	    if (nlines == 0) nlines++;
1022 	    if (comchar == 'f')
1023 		nlines *= dlines;
1024 	    putchar ('\r');
1025 	    erase (0);
1026 	    printf ("\n");
1027 	    if (clreol)
1028 		cleareol ();
1029 	    printf ("...skipping %d line", nlines);
1030 	    if (nlines > 1)
1031 		pr ("s\n");
1032 	    else
1033 		pr ("\n");
1034 
1035 	    if (clreol)
1036 		cleareol ();
1037 	    pr ("\n");
1038 
1039 	    while (nlines > 0) {
1040 		while ((c = Getc (f)) != '\n')
1041 		    if (c == EOF) {
1042 			retval = 0;
1043 			done++;
1044 			goto endsw;
1045 		    }
1046 		    Currline++;
1047 		    nlines--;
1048 	    }
1049 	    ret (dlines);
1050 	case '\n':
1051 	    if (nlines != 0)
1052 		dlines = nlines;
1053 	    else
1054 		nlines = 1;
1055 	    ret (nlines);
1056 	case '\f':
1057 	    if (!no_intty) {
1058 		doclear ();
1059 		Fseek (f, screen_start.chrctr);
1060 		Currline = screen_start.line;
1061 		ret (dlines);
1062 	    }
1063 	    else {
1064 		write (2, &bell, 1);
1065 		break;
1066 	    }
1067 	case '\'':
1068 	    if (!no_intty) {
1069 		kill_line ();
1070 		pr ("\n***Back***\n\n");
1071 		Fseek (f, context.chrctr);
1072 		Currline = context.line;
1073 		ret (dlines);
1074 	    }
1075 	    else {
1076 		write (2, &bell, 1);
1077 		break;
1078 	    }
1079 	case '=':
1080 	    kill_line ();
1081 	    promptlen = printd (Currline);
1082 	    fflush (stdout);
1083 	    break;
1084 	case 'n':
1085 	    lastp++;
1086 	case '/':
1087 	    if (nlines == 0) nlines++;
1088 	    kill_line ();
1089 	    pr ("/");
1090 	    promptlen = 1;
1091 	    fflush (stdout);
1092 	    if (lastp) {
1093 		write (2,"\r", 1);
1094 		search (NULL, f, nlines);	/* Use previous r.e. */
1095 	    }
1096 	    else {
1097 		ttyin (cmdbuf, 78, '/');
1098 		write (2, "\r", 1);
1099 		search (cmdbuf, f, nlines);
1100 	    }
1101 	    ret (dlines-1);
1102 	case '!':
1103 	    do_shell (filename);
1104 	    break;
1105 	case '?':
1106 	case 'h':
1107 	    if ((helpf = fopen (HELPFILE, "r")) == NULL)
1108 		error ("Can't open help file");
1109 	    if (noscroll) doclear ();
1110 	    copy_file (helpf);
1111 	    fclose (helpf);
1112 	    prompt (filename);
1113 	    break;
1114 	case 'v':	/* This case should go right before default */
1115 	    if (!no_intty) {
1116 		kill_line ();
1117 		cmdbuf[0] = '+';
1118 		scanstr (Currline - dlines < 0 ? 0
1119 				: Currline - (dlines + 1) / 2, &cmdbuf[1]);
1120 		pr ("vi "); pr (cmdbuf); putchar (' '); pr (fnames[fnum]);
1121 		execute (filename, VI, "vi", cmdbuf, fnames[fnum], 0);
1122 		break;
1123 	    }
1124 	default:
1125 	    if (dum_opt) {
1126    		kill_line ();
1127 		if (Senter && Sexit) {
1128 		    tputs (Senter, 1, putch);
1129 		    promptlen = pr ("[Press 'h' for instructions.]") + (2 * soglitch);
1130 		    tputs (Sexit, 1, putch);
1131 		}
1132 		else
1133 		    promptlen = pr ("[Press 'h' for instructions.]");
1134 		fflush (stdout);
1135 	    }
1136 	    else
1137 		write (2, &bell, 1);
1138 	    break;
1139 	}
1140 	if (done) break;
1141     }
1142     putchar ('\r');
1143 endsw:
1144     inwait = 0;
1145     notell++;
1146     if (MBIT == RAW && slow_tty) {
1147 	otty.sg_flags &= ~MBIT;
1148 	stty(fileno(stderr), &otty);
1149     }
1150     return (retval);
1151 }
1152 
1153 char ch;
1154 
1155 /*
1156  * Execute a colon-prefixed command.
1157  * Returns <0 if not a command that should cause
1158  * more of the file to be printed.
1159  */
1160 
1161 colon (filename, cmd, nlines)
1162 char *filename;
1163 int cmd;
1164 int nlines;
1165 {
1166 	if (cmd == 0)
1167 		ch = readch ();
1168 	else
1169 		ch = cmd;
1170 	lastcolon = ch;
1171 	switch (ch) {
1172 	case 'f':
1173 		kill_line ();
1174 		if (!no_intty)
1175 			promptlen = printf ("\"%s\" line %d", fnames[fnum], Currline);
1176 		else
1177 			promptlen = printf ("[Not a file] line %d", Currline);
1178 		fflush (stdout);
1179 		return (-1);
1180 	case 'n':
1181 		if (nlines == 0) {
1182 			if (fnum >= nfiles - 1)
1183 				end_it ();
1184 			nlines++;
1185 		}
1186 		putchar ('\r');
1187 		erase (0);
1188 		skipf (nlines);
1189 		return (0);
1190 	case 'p':
1191 		if (no_intty) {
1192 			write (2, &bell, 1);
1193 			return (-1);
1194 		}
1195 		putchar ('\r');
1196 		erase (0);
1197 		if (nlines == 0)
1198 			nlines++;
1199 		skipf (-nlines);
1200 		return (0);
1201 	case '!':
1202 		do_shell (filename);
1203 		return (-1);
1204 	case 'q':
1205 	case 'Q':
1206 		end_it ();
1207 	default:
1208 		write (2, &bell, 1);
1209 		return (-1);
1210 	}
1211 }
1212 
1213 /*
1214 ** Read a decimal number from the terminal. Set cmd to the non-digit which
1215 ** terminates the number.
1216 */
1217 
1218 number(cmd)
1219 char *cmd;
1220 {
1221 	register int i;
1222 
1223 	i = 0; ch = otty.sg_kill;
1224 	for (;;) {
1225 		ch = readch ();
1226 		if (ch >= '0' && ch <= '9')
1227 			i = i*10 + ch - '0';
1228 		else if (ch == otty.sg_kill)
1229 			i = 0;
1230 		else {
1231 			*cmd = ch;
1232 			break;
1233 		}
1234 	}
1235 	return (i);
1236 }
1237 
1238 do_shell (filename)
1239 char *filename;
1240 {
1241 	char cmdbuf[80];
1242 
1243 	kill_line ();
1244 	pr ("!");
1245 	fflush (stdout);
1246 	promptlen = 1;
1247 	if (lastp)
1248 		pr (shell_line);
1249 	else {
1250 		ttyin (cmdbuf, 78, '!');
1251 		if (expand (shell_line, cmdbuf)) {
1252 			kill_line ();
1253 			promptlen = printf ("!%s", shell_line);
1254 		}
1255 	}
1256 	fflush (stdout);
1257 	write (2, "\n", 1);
1258 	promptlen = 0;
1259 	shellp = 1;
1260 	execute (filename, shell, shell, "-c", shell_line, 0);
1261 }
1262 
1263 /*
1264 ** Search for nth ocurrence of regular expression contained in buf in the file
1265 */
1266 
1267 search (buf, file, n)
1268 char buf[];
1269 FILE *file;
1270 register int n;
1271 {
1272     long startline = Ftell (file);
1273     register long line1 = startline;
1274     register long line2 = startline;
1275     register long line3 = startline;
1276     register int lncount;
1277     int saveln, rv, re_exec();
1278     char *s, *re_comp();
1279 
1280     context.line = saveln = Currline;
1281     context.chrctr = startline;
1282     lncount = 0;
1283     if ((s = re_comp (buf)) != 0)
1284 	error (s);
1285     while (!feof (file)) {
1286 	line3 = line2;
1287 	line2 = line1;
1288 	line1 = Ftell (file);
1289 	rdline (file);
1290 	lncount++;
1291 	if ((rv = re_exec (Line)) == 1)
1292 		if (--n == 0) {
1293 		    if (lncount > 3 || (lncount > 1 && no_intty))
1294 		    {
1295 			pr ("\n");
1296 			if (clreol)
1297 			    cleareol ();
1298 			pr("...skipping\n");
1299 		    }
1300 		    if (!no_intty) {
1301 			Currline -= (lncount >= 3 ? 3 : lncount);
1302 			Fseek (file, line3);
1303 			if (noscroll)
1304 			    if (clreol) {
1305 				home ();
1306 				cleareol ();
1307 			    }
1308 			    else
1309 				doclear ();
1310 		    }
1311 		    else {
1312 			kill_line ();
1313 			if (noscroll)
1314 			    if (clreol) {
1315 			        home ();
1316 			        cleareol ();
1317 			    }
1318 			    else
1319 				doclear ();
1320 			pr (Line);
1321 			putchar ('\n');
1322 		    }
1323 		    break;
1324 		}
1325 	else if (rv == -1)
1326 	    error ("Regular expression botch");
1327     }
1328     if (feof (file)) {
1329 	if (!no_intty) {
1330 	    file->_flag &= ~_IOEOF; /* why doesn't fseek do this ??!!??! */
1331 	    Currline = saveln;
1332 	    Fseek (file, startline);
1333 	}
1334 	else {
1335 	    pr ("\nPattern not found\n");
1336 	    end_it ();
1337 	}
1338 	error ("Pattern not found");
1339     }
1340 }
1341 
1342 execute (filename, cmd, args)
1343 char *filename;
1344 char *cmd, *args;
1345 {
1346 	int id;
1347 	int n;
1348 
1349 	fflush (stdout);
1350 	reset_tty ();
1351 	for (n = 10; (id = fork ()) < 0 && n > 0; n--)
1352 	    sleep (5);
1353 	if (id == 0) {
1354 	    if (!isatty(0)) {
1355 		close(0);
1356 		open("/dev/tty", 0);
1357 	    }
1358 	    execv (cmd, &args);
1359 	    write (2, "exec failed\n", 12);
1360 	    exit (1);
1361 	}
1362 	if (id > 0) {
1363 	    signal (SIGINT, SIG_IGN);
1364 	    signal (SIGQUIT, SIG_IGN);
1365 	    if (catch_susp)
1366 		signal(SIGTSTP, SIG_DFL);
1367 	    while (wait(0) > 0);
1368 	    signal (SIGINT, end_it);
1369 	    signal (SIGQUIT, onquit);
1370 	    if (catch_susp)
1371 		signal(SIGTSTP, onsusp);
1372 	} else
1373 	    write(2, "can't fork\n", 11);
1374 	set_tty ();
1375 	pr ("------------------------\n");
1376 	prompt (filename);
1377 }
1378 /*
1379 ** Skip n lines in the file f
1380 */
1381 
1382 skiplns (n, f)
1383 register int n;
1384 register FILE *f;
1385 {
1386     register char c;
1387 
1388     while (n > 0) {
1389 	while ((c = Getc (f)) != '\n')
1390 	    if (c == EOF)
1391 		return;
1392 	    n--;
1393 	    Currline++;
1394     }
1395 }
1396 
1397 /*
1398 ** Skip nskip files in the file list (from the command line). Nskip may be
1399 ** negative.
1400 */
1401 
1402 skipf (nskip)
1403 register int nskip;
1404 {
1405     if (nskip == 0) return;
1406     if (nskip > 0) {
1407 	if (fnum + nskip > nfiles - 1)
1408 	    nskip = nfiles - fnum - 1;
1409     }
1410     else if (within)
1411 	++fnum;
1412     fnum += nskip;
1413     if (fnum < 0)
1414 	fnum = 0;
1415     pr ("\n...Skipping ");
1416     pr ("\n");
1417     if (clreol)
1418 	cleareol ();
1419     pr ("...Skipping ");
1420     pr (nskip > 0 ? "to file " : "back to file ");
1421     pr (fnames[fnum]);
1422     pr ("\n");
1423     if (clreol)
1424 	cleareol ();
1425     pr ("\n");
1426     --fnum;
1427 }
1428 
1429 /*----------------------------- Terminal I/O -------------------------------*/
1430 
1431 initterm ()
1432 {
1433     char	buf[TBUFSIZ];
1434     static char	clearbuf[TBUFSIZ];
1435     char	*clearptr, *padstr;
1436     int		ldisc;
1437     int		lmode;
1438     char	*term;
1439     int		tgrp;
1440     struct winsize win;
1441 
1442 retry:
1443     if (!(no_tty = gtty(fileno(stdout), &otty))) {
1444 	if (ioctl(fileno(stdout), TIOCLGET, &lmode) < 0) {
1445 	    perror("TIOCLGET");
1446 	    exit(1);
1447 	}
1448 	docrterase = ((lmode & LCRTERA) != 0);
1449 	docrtkill = ((lmode & LCRTKIL) != 0);
1450 	/*
1451 	 * Wait until we're in the foreground before we save the
1452 	 * the terminal modes.
1453 	 */
1454 	if (ioctl(fileno(stdout), TIOCGPGRP, &tgrp) < 0) {
1455 	    perror("TIOCGPGRP");
1456 	    exit(1);
1457 	}
1458 	if (tgrp != getpgrp(0)) {
1459 	    kill(0, SIGTTOU);
1460 	    goto retry;
1461 	}
1462 	if ((term = getenv("TERM")) == 0 || tgetent(buf, term) <= 0) {
1463 	    dumb++; ul_opt = 0;
1464 	}
1465 	else {
1466 	    if (ioctl(fileno(stdout), TIOCGWINSZ, &win) < 0) {
1467 		Lpp = tgetnum("li");
1468 		Mcol = tgetnum("co");
1469 	    } else {
1470 		if ((Lpp = win.ws_row) == 0)
1471 		    Lpp = tgetnum("li");
1472 		if ((Mcol = win.ws_col) == 0)
1473 		    Mcol = tgetnum("co");
1474 	    }
1475 	    if ((Lpp <= 0) || tgetflag("hc")) {
1476 		hard++;	/* Hard copy terminal */
1477 		Lpp = 24;
1478 	    }
1479 	    if (Mcol <= 0)
1480 		Mcol = 80;
1481 
1482 	    if (tailequ (fnames[0], "page") || !hard && tgetflag("ns"))
1483 		noscroll++;
1484 	    Wrap = tgetflag("am");
1485 	    bad_so = tgetflag ("xs");
1486 	    clearptr = clearbuf;
1487 	    eraseln = tgetstr("ce",&clearptr);
1488 	    Clear = tgetstr("cl", &clearptr);
1489 	    Senter = tgetstr("so", &clearptr);
1490 	    Sexit = tgetstr("se", &clearptr);
1491 	    if ((soglitch = tgetnum("sg")) < 0)
1492 		soglitch = 0;
1493 
1494 	    /*
1495 	     *  Set up for underlining:  some terminals don't need it;
1496 	     *  others have start/stop sequences, still others have an
1497 	     *  underline char sequence which is assumed to move the
1498 	     *  cursor forward one character.  If underline sequence
1499 	     *  isn't available, settle for standout sequence.
1500 	     */
1501 
1502 	    if (tgetflag("ul") || tgetflag("os"))
1503 		ul_opt = 0;
1504 	    if ((chUL = tgetstr("uc", &clearptr)) == NULL )
1505 		chUL = "";
1506 	    if (((ULenter = tgetstr("us", &clearptr)) == NULL ||
1507 	         (ULexit = tgetstr("ue", &clearptr)) == NULL) && !*chUL) {
1508 	        if ((ULenter = Senter) == NULL || (ULexit = Sexit) == NULL) {
1509 			ULenter = "";
1510 			ULexit = "";
1511 		} else
1512 			ulglitch = soglitch;
1513 	    } else {
1514 		if ((ulglitch = tgetnum("ug")) < 0)
1515 		    ulglitch = 0;
1516 	    }
1517 
1518 	    if (padstr = tgetstr("pc", &clearptr))
1519 		PC = *padstr;
1520 	    Home = tgetstr("ho",&clearptr);
1521 	    if (Home == 0 || *Home == '\0')
1522 	    {
1523 		if ((cursorm = tgetstr("cm", &clearptr)) != NULL) {
1524 		    strcpy(cursorhome, tgoto(cursorm, 0, 0));
1525 		    Home = cursorhome;
1526 	       }
1527 	    }
1528 	    EodClr = tgetstr("cd", &clearptr);
1529 	    if ((chBS = tgetstr("bc", &clearptr)) == NULL)
1530 		chBS = "\b";
1531 
1532 	}
1533 	if ((shell = getenv("SHELL")) == NULL)
1534 	    shell = "/bin/sh";
1535     }
1536     no_intty = gtty(fileno(stdin), &otty);
1537     gtty(fileno(stderr), &otty);
1538     savetty = otty;
1539     ospeed = otty.sg_ospeed;
1540     slow_tty = ospeed < B1200;
1541     hardtabs = (otty.sg_flags & TBDELAY) != XTABS;
1542     if (!no_tty) {
1543 	otty.sg_flags &= ~ECHO;
1544 	if (MBIT == CBREAK || !slow_tty)
1545 	    otty.sg_flags |= MBIT;
1546     }
1547 }
1548 
1549 readch ()
1550 {
1551 	char ch;
1552 	extern int errno;
1553 
1554 	if (read (2, &ch, 1) <= 0)
1555 		if (errno != EINTR)
1556 			exit(0);
1557 		else
1558 			ch = otty.sg_kill;
1559 	return (ch);
1560 }
1561 
1562 static char BS = '\b';
1563 static char *BSB = "\b \b";
1564 static char CARAT = '^';
1565 #define ERASEONECHAR \
1566     if (docrterase) \
1567 	write (2, BSB, sizeof(BSB)); \
1568     else \
1569 	write (2, &BS, sizeof(BS));
1570 
1571 ttyin (buf, nmax, pchar)
1572 char buf[];
1573 register int nmax;
1574 char pchar;
1575 {
1576     register char *sptr;
1577     register char ch;
1578     register int slash = 0;
1579     int	maxlen;
1580     char cbuf;
1581 
1582     sptr = buf;
1583     maxlen = 0;
1584     while (sptr - buf < nmax) {
1585 	if (promptlen > maxlen) maxlen = promptlen;
1586 	ch = readch ();
1587 	if (ch == '\\') {
1588 	    slash++;
1589 	}
1590 	else if ((ch == otty.sg_erase) && !slash) {
1591 	    if (sptr > buf) {
1592 		--promptlen;
1593 		ERASEONECHAR
1594 		--sptr;
1595 		if ((*sptr < ' ' && *sptr != '\n') || *sptr == RUBOUT) {
1596 		    --promptlen;
1597 		    ERASEONECHAR
1598 		}
1599 		continue;
1600 	    }
1601 	    else {
1602 		if (!eraseln) promptlen = maxlen;
1603 		longjmp (restore, 1);
1604 	    }
1605 	}
1606 	else if ((ch == otty.sg_kill) && !slash) {
1607 	    if (hard) {
1608 		show (ch);
1609 		putchar ('\n');
1610 		putchar (pchar);
1611 	    }
1612 	    else {
1613 		putchar ('\r');
1614 		putchar (pchar);
1615 		if (eraseln)
1616 		    erase (1);
1617 		else if (docrtkill)
1618 		    while (promptlen-- > 1)
1619 			write (2, BSB, sizeof(BSB));
1620 		promptlen = 1;
1621 	    }
1622 	    sptr = buf;
1623 	    fflush (stdout);
1624 	    continue;
1625 	}
1626 	if (slash && (ch == otty.sg_kill || ch == otty.sg_erase)) {
1627 	    ERASEONECHAR
1628 	    --sptr;
1629 	}
1630 	if (ch != '\\')
1631 	    slash = 0;
1632 	*sptr++ = ch;
1633 	if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1634 	    ch += ch == RUBOUT ? -0100 : 0100;
1635 	    write (2, &CARAT, 1);
1636 	    promptlen++;
1637 	}
1638 	cbuf = ch;
1639 	if (ch != '\n' && ch != ESC) {
1640 	    write (2, &cbuf, 1);
1641 	    promptlen++;
1642 	}
1643 	else
1644 	    break;
1645     }
1646     *--sptr = '\0';
1647     if (!eraseln) promptlen = maxlen;
1648     if (sptr - buf >= nmax - 1)
1649 	error ("Line too long");
1650 }
1651 
1652 expand (outbuf, inbuf)
1653 char *outbuf;
1654 char *inbuf;
1655 {
1656     register char *instr;
1657     register char *outstr;
1658     register char ch;
1659     char temp[200];
1660     int changed = 0;
1661 
1662     instr = inbuf;
1663     outstr = temp;
1664     while ((ch = *instr++) != '\0')
1665 	switch (ch) {
1666 	case '%':
1667 	    if (!no_intty) {
1668 		strcpy (outstr, fnames[fnum]);
1669 		outstr += strlen (fnames[fnum]);
1670 		changed++;
1671 	    }
1672 	    else
1673 		*outstr++ = ch;
1674 	    break;
1675 	case '!':
1676 	    if (!shellp)
1677 		error ("No previous command to substitute for");
1678 	    strcpy (outstr, shell_line);
1679 	    outstr += strlen (shell_line);
1680 	    changed++;
1681 	    break;
1682 	case '\\':
1683 	    if (*instr == '%' || *instr == '!') {
1684 		*outstr++ = *instr++;
1685 		break;
1686 	    }
1687 	default:
1688 	    *outstr++ = ch;
1689 	}
1690     *outstr++ = '\0';
1691     strcpy (outbuf, temp);
1692     return (changed);
1693 }
1694 
1695 show (ch)
1696 register char ch;
1697 {
1698     char cbuf;
1699 
1700     if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1701 	ch += ch == RUBOUT ? -0100 : 0100;
1702 	write (2, &CARAT, 1);
1703 	promptlen++;
1704     }
1705     cbuf = ch;
1706     write (2, &cbuf, 1);
1707     promptlen++;
1708 }
1709 
1710 error (mess)
1711 char *mess;
1712 {
1713     if (clreol)
1714 	cleareol ();
1715     else
1716 	kill_line ();
1717     promptlen += strlen (mess);
1718     if (Senter && Sexit) {
1719 	tputs (Senter, 1, putch);
1720 	pr(mess);
1721 	tputs (Sexit, 1, putch);
1722     }
1723     else
1724 	pr (mess);
1725     fflush(stdout);
1726     errors++;
1727     longjmp (restore, 1);
1728 }
1729 
1730 
1731 set_tty ()
1732 {
1733 	otty.sg_flags |= MBIT;
1734 	otty.sg_flags &= ~ECHO;
1735 	stty(fileno(stderr), &otty);
1736 }
1737 
1738 reset_tty ()
1739 {
1740     if (pstate) {
1741 	tputs(ULexit, 1, putch);
1742 	fflush(stdout);
1743 	pstate = 0;
1744     }
1745     otty.sg_flags |= ECHO;
1746     otty.sg_flags &= ~MBIT;
1747     stty(fileno(stderr), &savetty);
1748 }
1749 
1750 rdline (f)
1751 register FILE *f;
1752 {
1753     register char c;
1754     register char *p;
1755 
1756     p = Line;
1757     while ((c = Getc (f)) != '\n' && c != EOF && p - Line < LINSIZ - 1)
1758 	*p++ = c;
1759     if (c == '\n')
1760 	Currline++;
1761     *p = '\0';
1762 }
1763 
1764 /* Come here when we get a suspend signal from the terminal */
1765 
1766 onsusp ()
1767 {
1768     /* ignore SIGTTOU so we don't get stopped if csh grabs the tty */
1769     signal(SIGTTOU, SIG_IGN);
1770     reset_tty ();
1771     fflush (stdout);
1772     signal(SIGTTOU, SIG_DFL);
1773     /* Send the TSTP signal to suspend our process group */
1774     signal(SIGTSTP, SIG_DFL);
1775     sigsetmask(0);
1776     kill (0, SIGTSTP);
1777     /* Pause for station break */
1778 
1779     /* We're back */
1780     signal (SIGTSTP, onsusp);
1781     set_tty ();
1782     if (inwait)
1783 	    longjmp (restore);
1784 }
1785