xref: /csrg-svn/old/more/more.c (revision 1500)
1 static char *SCCS_ID = "@(#)more.c	4.1 (Berkeley) 10/17/80";
2 /*
3 ** more.c - General purpose tty output filter and file perusal program
4 **
5 **	by Eric Shienbrood, UC Berkeley
6 */
7 
8 #include <whoami.h>
9 #ifdef V6
10 #include <retrofit.h>
11 #endif
12 #include <stdio.h>
13 #include <ctype.h>
14 #include <signal.h>
15 #include <errno.h>
16 #include <sgtty.h>
17 #include <setjmp.h>
18 #include <sys/types.h>
19 #include <sys/dir.h>
20 #include <sys/stat.h>
21 #include <local/uparm.h>
22 
23 /* Help file will eventually go in libpath(more.help) on all systems */
24 
25 #ifdef INGRES
26 #define VI		"/usr/bin/vi"
27 #define HELPFILE	"/mntp/doucette/more/more.help"
28 #endif
29 
30 #ifndef INGRES
31 #ifndef HELPFILE
32 #define HELPFILE	libpath(more.help)
33 #endif
34 #define VI		binpath(vi)
35 #endif
36 
37 #define Fopen(s,m)	(Currline = 0,file_pos=0,fopen(s,m))
38 #define Ftell(f)	file_pos
39 #define Fseek(f,off)	(file_pos=off,fseek(f,off,0))
40 #define Getc(f)		(++file_pos, getc(f))
41 #define Ungetc(c,f)	(--file_pos, ungetc(c,f))
42 
43 #ifdef V6
44 #define MBIT	RAW
45 #define CBREAK	~RAW
46 #else
47 #define MBIT	CBREAK
48 #define stty(fd,argp)	ioctl(fd,TIOCSETN,argp)
49 #endif
50 
51 #define TBUFSIZ	1024
52 #define LINSIZ	256
53 #define ctrl(letter)	('letter' & 077)
54 #define RUBOUT	'\177'
55 #define ESC	'\033'
56 #define QUIT	'\034'
57 
58 struct sgttyb 	otty;
59 long		file_pos, file_size;
60 int		fnum, no_intty, no_tty, slow_tty;
61 int		dum_opt, dlines, onquit(), end_it();
62 #ifdef SIGTSTP
63 int		onsusp();
64 #endif
65 int		nscroll = 11;	/* Number of lines scrolled by 'd' */
66 int		fold_opt = 1;	/* Fold long lines */
67 int		stop_opt = 1;	/* Stop after form feeds */
68 int		promptlen;
69 int		Currline;	/* Line we are currently at */
70 int		startup = 1;
71 int		firstf = 1;
72 int		notell = 1;
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;
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		obuf[BUFSIZ];	/* stdout buffer */
86 char		Line[LINSIZ];	/* Line buffer */
87 int		Lpp = 24;	/* lines per page */
88 char		*Clear;		/* clear screen */
89 char		*eraseln;	/* erase line */
90 char		*Senter, *Sexit;/* enter and exit standout mode */
91 char		*tgetstr();
92 int		Mcol = 80;	/* number of columns */
93 int		Wrap = 1;	/* set if automargins */
94 long		fseek();
95 struct {
96     long chrctr, line;
97 } context, screen_start;
98 extern char	PC;		/* pad character */
99 extern short	ospeed;
100 
101 
102 main(argc, argv)
103 int argc;
104 char *argv[];
105 {
106     register FILE	*f;
107     register char	*s;
108     register char	*p;
109     register char	ch;
110     register int	left;
111     int			prnames = 0;
112     int			initopt = 0;
113     int			srchopt = 0;
114     int			clearit = 0;
115     int			initline;
116     char		initbuf[80];
117     FILE		*checkf();
118 
119     nfiles = argc;
120     fnames = argv;
121     initterm ();
122     while (--nfiles > 0) {
123 	if ((ch = (*++fnames)[0]) == '-') {
124 	    for (s = fnames[0] + 1, dlines = 0; *s != '\0'; s++)
125 		if (isdigit(*s))
126 		    dlines = dlines*10 + *s - '0';
127 		else if (*s == 'd')
128 		    dum_opt = 1;
129 		else if (*s == 'l')
130 		    stop_opt = 0;
131 		else if (*s == 'f')
132 		    fold_opt = 0;
133 	}
134 	else if (ch == '+') {
135 	    s = *fnames;
136 	    if (*++s == '/') {
137 		srchopt++;
138 		for (++s, p = initbuf; p < initbuf + 79 && *s != '\0';)
139 		    *p++ = *s++;
140 		*p = '\0';
141 	    }
142 	    else {
143 		initopt++;
144 		for (initline = 0; *s != '\0'; s++)
145 		    if (isdigit (*s))
146 			initline = initline*10 + *s -'0';
147 		--initline;
148 	    }
149 	}
150 	else break;
151     }
152     if (dlines == 0)
153 	dlines = Lpp - (noscroll ? 1 : 2);
154     left = dlines;
155     if (nfiles > 1)
156 	prnames++;
157     if (!no_intty && nfiles == 0) {
158 	fputs("Usage: ",stderr);
159 	fputs(argv[0],stderr);
160 	fputs(" [-dfln] [+linenum | +/pattern] name1 name2 ...\n",stderr);
161 	exit(1);
162     }
163     else
164 	f = stdin;
165     if (!no_tty) {
166 	signal(SIGQUIT, onquit);
167 	signal(SIGINT, end_it);
168 #ifdef SIGTSTP
169 	if (signal (SIGTSTP, SIG_IGN) == SIG_DFL) {
170 	    signal(SIGTSTP, onsusp);
171 	    catch_susp++;
172 	}
173 #endif
174 	stty (2, &otty);
175     }
176     if (no_intty) {
177 	if (no_tty)
178 	    copy_file (stdin);
179 	else {
180 	    if ((ch = Getc (f)) == '\f')
181 		doclear ();
182 	    else {
183 		Ungetc (ch, f);
184 		if (noscroll)
185 		    doclear ();
186 	    }
187 	    if (srchopt)
188 		search (initbuf, stdin, 1);
189 	    else if (initopt)
190 		skiplns (initline, stdin);
191 	    screen (stdin, left);
192 	}
193 	no_intty = 0;
194 	prnames++;
195 	firstf = 0;
196     }
197 
198     while (fnum < nfiles) {
199 	if ((f = checkf (fnames[fnum], &clearit)) != NULL) {
200 	    context.line = context.chrctr = 0;
201 	    Currline = 0;
202 	    if (firstf) setjmp (restore);
203 	    if (firstf) {
204 		firstf = 0;
205 		if (srchopt)
206 		    search (initbuf, f, 1);
207 		else if (initopt)
208 		    skiplns (initline, f);
209 	    }
210 	    else if (fnum < nfiles && !no_tty) {
211 		setjmp (restore);
212 		left = command (fnames[fnum], f);
213 	    }
214 	    if (left != 0) {
215 		if (noscroll || clearit)
216 		    doclear ();
217 		if (prnames) {
218 		    if (bad_so)
219 			erase (0);
220 		    pr("::::::::::::::");
221 		    if (promptlen > 14)
222 			erase (14);
223 		    printf ("\n%s\n::::::::::::::\n", fnames[fnum]);
224 		    if (left > Lpp - 4)
225 			left = Lpp - 4;
226 		}
227 		if (no_tty)
228 		    copy_file (f);
229 		else {
230 		    within++;
231 		    screen(f, left);
232 		    within = 0;
233 		}
234 	    }
235 	    setjmp (restore);
236 	    fflush(stdout);
237 	    fclose(f);
238 	    screen_start.line = screen_start.chrctr = 0L;
239 	    context.line = context.chrctr = 0L;
240 	}
241 	fnum++;
242 	firstf = 0;
243     }
244     reset_tty ();
245     exit(0);
246 }
247 
248 /*
249 ** Check whether the file named by fs is an ASCII file which the user may
250 ** access.  If it is, return the opened file. Otherwise return NULL.
251 */
252 
253 FILE *
254 checkf (fs, clearfirst)
255 register char *fs;
256 int *clearfirst;
257 {
258     struct stat stbuf;
259     register FILE *f;
260     char c;
261 
262     if (stat (fs, &stbuf) == -1) {
263 	fflush(stdout);
264 	perror(fs);
265 	return (NULL);
266     }
267     if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
268 	printf("\n*** %s: directory ***\n\n", fs);
269 	return (NULL);
270     }
271     if ((f=Fopen(fs, "r")) == NULL) {
272 	fflush(stdout);
273 	perror(fs);
274 	return (NULL);
275     }
276     c = Getc(f);
277 
278     /* Try to see whether it is an ASCII file */
279 
280     switch ((c | *f->_ptr << 8) & 0177777) {
281     case 0405:
282     case 0407:
283     case 0410:
284     case 0411:
285     case 0413:
286     case 0177545:
287 	printf("\n******** %s: Not a text file ********\n\n", fs);
288 	fclose (f);
289 	return (NULL);
290     default:
291 	break;
292     }
293     if (c == '\f')
294 	*clearfirst = 1;
295     else {
296 	*clearfirst = 0;
297 	Ungetc (c, f);
298     }
299     if ((file_size = stbuf.st_size) == 0)
300 	file_size = 0x7fffffffffffffffL;
301     return (f);
302 }
303 
304 /*
305 ** A real function, for the tputs routine in termlib
306 */
307 
308 putch (ch)
309 char ch;
310 {
311     putchar (ch);
312 }
313 
314 /*
315 ** Print out the contents of the file f, one screenful at a time.
316 */
317 
318 #define STOP -10
319 
320 screen (f, num_lines)
321 register FILE *f;
322 register int num_lines;
323 {
324     register int c;
325     register int nchars;
326     int length;
327 
328     for (;;) {
329 	while (num_lines > 0 && !Pause) {
330 	    if ((nchars = getline (f, &length)) == EOF)
331 		return;
332 	    if (bad_so || (Senter && *Senter == ' ') && promptlen > 0)
333 		erase (0);
334 	    prbuf (Line, length);
335 	    if (nchars < promptlen)
336 		erase (nchars);	/* erase () sets promptlen to 0 */
337 	    else promptlen = 0;
338 	    if (nchars < Mcol || !fold_opt)
339 		putchar('\n');
340 	    if (nchars == STOP)
341 		break;
342 	    num_lines--;
343 	}
344 	fflush(stdout);
345 	if ((c = Getc(f)) == EOF)
346 	    return;
347 	Ungetc (c, f);
348 	setjmp (restore);
349 	Pause = 0; startup = 0;
350 	if ((num_lines = command (NULL, f)) == 0)
351 	    return;
352 	if (hard && promptlen > 0)
353 		erase (0);
354 	if (noscroll && num_lines == dlines)
355 		doclear ();
356 	screen_start.line = Currline;
357 	screen_start.chrctr = Ftell (f);
358     }
359 }
360 
361 /*
362 ** Come here if a quit signal is received
363 */
364 
365 onquit()
366 {
367     signal(SIGQUIT, SIG_IGN);
368     if (!inwait) {
369 	putchar ('\n');
370 	if (!startup) {
371 	    signal(SIGQUIT, onquit);
372 	    longjmp (restore, 1);
373 	}
374 	else
375 	    Pause++;
376     }
377     else if (!dum_opt && notell) {
378 	write (2, "[Use q or Q to quit]", 20);
379 	promptlen += 20;
380 	notell = 0;
381     }
382     signal(SIGQUIT, onquit);
383 }
384 
385 /*
386 ** Clean up terminal state and exit. Also come here if interrupt signal received
387 */
388 
389 end_it ()
390 {
391 
392     reset_tty ();
393     if (promptlen > 0) {
394 	kill_line ();
395 	fflush (stdout);
396     }
397     else
398 	write (2, "\n", 1);
399     _exit(0);
400 }
401 
402 copy_file(f)
403 register FILE *f;
404 {
405     register int c;
406 
407     while ((c = getc(f)) != EOF)
408 	putchar(c);
409 }
410 
411 /* Simplified printf function */
412 
413 printf (fmt, args)
414 register char *fmt;
415 int args;
416 {
417 	register int *argp;
418 	register char ch;
419 	register int ccount;
420 
421 	ccount = 0;
422 	argp = &args;
423 	while (*fmt) {
424 		while ((ch = *fmt++) != '%') {
425 			if (ch == '\0')
426 				return (ccount);
427 			ccount++;
428 			putchar (ch);
429 		}
430 		switch (*fmt++) {
431 		case 'd':
432 			ccount += printd (*argp);
433 			break;
434 		case 's':
435 			ccount += pr ((char *)*argp);
436 			break;
437 		case '%':
438 			ccount++;
439 			argp--;
440 			putchar ('%');
441 			break;
442 		case '0':
443 			return (ccount);
444 		default:
445 			break;
446 		}
447 		++argp;
448 	}
449 	return (ccount);
450 
451 }
452 
453 /*
454 ** Print an integer as a string of decimal digits,
455 ** returning the length of the print representation.
456 */
457 
458 printd (n)
459 int n;
460 {
461     int a, nchars;
462 
463     if (a = n/10)
464 	nchars = 1 + printd(a);
465     else
466 	nchars = 1;
467     putchar (n % 10 + '0');
468     return (nchars);
469 }
470 
471 /* Put the print representation of an integer into a string */
472 static char *sptr;
473 
474 scanstr (n, str)
475 int n;
476 char *str;
477 {
478     sptr = str;
479     sprintf (n);
480     *sptr = '\0';
481 }
482 
483 sprintf (n)
484 {
485     int a;
486 
487     if (a = n/10)
488 	sprintf (a);
489     *sptr++ = n % 10 + '0';
490 }
491 
492 static char bell = ctrl(G);
493 
494 strlen (s)
495 char *s;
496 {
497     register char *p;
498 
499     p = s;
500     while (*p++)
501 	;
502     return (p - s - 1);
503 }
504 
505 /* See whether the last component of the path name "path" is equal to the
506 ** string "string"
507 */
508 
509 tailequ (path, string)
510 char *path;
511 register char *string;
512 {
513 	register char *tail;
514 
515 	tail = path + strlen(path);
516 	while (tail >= path)
517 		if (*(--tail) == '/')
518 			break;
519 	++tail;
520 	while (*tail++ == *string++)
521 		if (*tail == '\0')
522 			return(1);
523 	return(0);
524 }
525 
526 prompt (filename)
527 char *filename;
528 {
529     if (promptlen > 0)
530 	kill_line ();
531     if (!hard) {
532 	promptlen = 8;
533 	if (Senter && Sexit)
534 	    tputs (Senter, 1, putch);
535 	pr("--More--");
536 	if (filename != NULL) {
537 	    promptlen += printf ("(Next file: %s)", filename);
538 	}
539 	else if (!no_intty) {
540 	    promptlen += printf ("(%d%%)", (int)((file_pos * 100) / file_size));
541 	}
542 	if (dum_opt) {
543 	    promptlen += pr("[Hit space to continue, Rubout to abort]");
544 	}
545 	if (Senter && Sexit)
546 	    tputs (Sexit, 1, putch);
547 	fflush(stdout);
548     }
549     else
550 	write (2, &bell, 1);
551     inwait++;
552 }
553 
554 /*
555 ** Get a logical line
556 */
557 
558 getline(f, length)
559 register FILE *f;
560 int *length;
561 {
562     register int	c;
563     register char	*p;
564     register int	column;
565     static int		colflg;
566 
567     p = Line;
568     column = 0;
569     c = Getc (f);
570     if (colflg && c == '\n') {
571 	Currline++;
572 	c = Getc (f);
573     }
574     while (p < &Line[LINSIZ - 1]) {
575 	if (c == EOF) {
576 	    if (p > Line) {
577 		*p = '\0';
578 		*length = p - Line;
579 		return (column);
580 	    }
581 	    *length = p - Line;
582 	    return (EOF);
583 	}
584 	if (c == '\n') {
585 	    Currline++;
586 	    break;
587 	}
588 	*p++ = c;
589 	if (c == '\t')
590 	    if (hardtabs && column < promptlen && !hard) {
591 		if (eraseln && !dumb) {
592 		    column = 1 + (column | 7);
593 		    tputs (eraseln, 1, putch);
594 		    promptlen = 0;
595 		}
596 		else {
597 		    for (--p; column & 7 && p < &Line[LINSIZ - 1]; column++) {
598 			*p++ = ' ';
599 		    }
600 		    if (column >= promptlen) promptlen = 0;
601 		}
602 	    }
603 	    else
604 		column = 1 + (column | 7);
605 	else if (c == '\b')
606 	    column--;
607 	else if (c == '\r')
608 	    column = 0;
609 	else if (c == '\f' && stop_opt) {
610 		p[-1] = '^';
611 		*p++ = 'L';
612 		column += 2;
613 		Pause++;
614 	}
615 	else if (c == EOF) {
616 	    *length = p - Line;
617 	    return (column);
618 	}
619 	else if (c >= ' ' && c != RUBOUT)
620 	    column++;
621 	if (column >= Mcol && fold_opt) break;
622 	c = Getc (f);
623     }
624     if (column >= Mcol && Mcol > 0) {
625 	if (!Wrap) {
626 	    *p++ = '\n';
627 	}
628     }
629     colflg = column == Mcol && fold_opt;
630     *length = p - Line;
631     *p = 0;
632     return (column);
633 }
634 
635 /*
636 ** Erase the rest of the prompt, assuming we are starting at column col.
637 */
638 
639 erase (col)
640 register int col;
641 {
642 
643     if (promptlen == 0)
644 	return;
645     if (hard) {
646 	putchar ('\n');
647     }
648     else {
649 	if (col == 0)
650 	    putchar ('\r');
651 	if (!dumb && eraseln)
652 	    tputs (eraseln, 1, putch);
653 	else
654 	    for (col = promptlen - col; col > 0; col--)
655 		putchar (' ');
656     }
657     promptlen = 0;
658 }
659 
660 /*
661 ** Erase the current line entirely
662 */
663 
664 kill_line ()
665 {
666     erase (0);
667     if (!eraseln || dumb) putchar ('\r');
668 }
669 
670 /*
671 **  Print string and return number of characters
672 */
673 
674 pr(s1)
675 char	*s1;
676 {
677     register char	*s;
678     register char	c;
679 
680     for (s = s1; c = *s++; )
681 	putchar(c);
682     return (s - s1 - 1);
683 }
684 
685 
686 /* Print a buffer of n characters */
687 
688 prbuf (s, n)
689 register char *s;
690 register int n;
691 {
692     while (n-- > 0)
693 	putchar (*s++);
694 }
695 
696 /*
697 **  Clear the screen
698 */
699 
700 doclear()
701 {
702     if (Clear && !hard) {
703 	tputs(Clear, 1, putch);
704 
705 	/* Put out carriage return so that system doesn't
706 	** get confused by escape sequences when expanding tabs
707 	*/
708 	putchar ('\r');
709 	promptlen = 0;
710     }
711 }
712 
713 static int lastcmd, lastarg, lastp;
714 static int lastcolon;
715 char shell_line[132];
716 
717 /*
718 ** Read a command and do it. A command consists of an optional integer
719 ** argument followed by the command character.  Return the number of lines
720 ** to display in the next screenful.  If there is nothing more to display
721 ** in the current file, zero is returned.
722 */
723 
724 command (filename, f)
725 char *filename;
726 register FILE *f;
727 {
728     register int nlines;
729     register int retval;
730     register char c;
731     char colonch;
732     FILE *helpf;
733     int done;
734     char comchar, cmdbuf[80], *p;
735 
736 #define ret(val) retval=val;done++;break
737 
738     done = 0;
739     if (!errors)
740 	prompt (filename);
741     else
742 	errors = 0;
743     if (MBIT == RAW && slow_tty) {
744 	otty.sg_flags |= MBIT;
745 	stty(2, &otty);
746     }
747     for (;;) {
748 	nlines = number (&comchar);
749 	lastp = colonch = 0;
750 	if (comchar == '.') {	/* Repeat last command */
751 		lastp++;
752 		comchar = lastcmd;
753 		nlines = lastarg;
754 		if (lastcmd == ':')
755 			colonch = lastcolon;
756 	}
757 	lastcmd = comchar;
758 	lastarg = nlines;
759 	if (comchar == otty.sg_erase) {
760 	    kill_line ();
761 	    prompt (filename);
762 	    continue;
763 	}
764 	switch (comchar) {
765 	case ':':
766 	    retval = colon (filename, colonch, nlines);
767 	    if (retval >= 0)
768 		done++;
769 	    break;
770 	case ' ':
771 	case 'z':
772 	    if (nlines == 0) nlines = dlines;
773 	    else if (comchar == 'z') dlines = nlines;
774 	    ret (nlines);
775 	case 'd':
776 	case ctrl(D):
777 	    if (nlines != 0) nscroll = nlines;
778 	    ret (nscroll);
779 	case RUBOUT:
780 	case 'q':
781 	case 'Q':
782 	    end_it ();
783 	case 's':
784 	case 'f':
785 	    if (nlines == 0) nlines++;
786 	    if (comchar == 'f')
787 		nlines *= dlines;
788 	    putchar ('\r');
789 	    erase (0);
790 	    printf("\n...skipping %d line", nlines);
791 	    if (nlines > 1)
792 		pr("s\n\n");
793 	    else
794 		pr("\n\n");
795 	    while (nlines > 0) {
796 		while ((c = Getc (f)) != '\n')
797 		    if (c == EOF) {
798 			retval = 0;
799 			done++;
800 			goto endsw;
801 		    }
802 		    Currline++;
803 		    nlines--;
804 	    }
805 	    ret (dlines);
806 	case '\n':
807 	    if (nlines != 0)
808 		dlines = nlines;
809 	    else
810 		nlines = 1;
811 	    ret (nlines);
812 	case '\f':
813 	    if (!no_intty) {
814 		doclear ();
815 		Fseek (f, screen_start.chrctr);
816 		Currline = screen_start.line;
817 		ret (dlines);
818 	    }
819 	    else {
820 		write (2, &bell, 1);
821 		break;
822 	    }
823 	case '\'':
824 	    if (!no_intty) {
825 		kill_line ();
826 		pr ("\n***Back***\n\n");
827 		Fseek (f, context.chrctr);
828 		Currline = context.line;
829 		ret (dlines);
830 	    }
831 	    else {
832 		write (2, &bell, 1);
833 		break;
834 	    }
835 	case '=':
836 	    kill_line ();
837 	    promptlen = printd (Currline);
838 	    fflush (stdout);
839 	    break;
840 	case 'n':
841 	    lastp++;
842 	case '/':
843 	    if (nlines == 0) nlines++;
844 	    kill_line ();
845 	    pr ("/");
846 	    promptlen = 1;
847 	    fflush (stdout);
848 	    if (lastp) {
849 		write (2,"\r", 1);
850 		search (NULL, f, nlines);	/* Use previous r.e. */
851 	    }
852 	    else {
853 		ttyin (cmdbuf, 78, '/');
854 		write (2, "\r", 1);
855 		search (cmdbuf, f, nlines);
856 	    }
857 	    ret (dlines);
858 	case '!':
859 	    do_shell (filename);
860 	    break;
861 	case 'h':
862 	    if ((helpf = fopen (HELPFILE, "r")) == NULL)
863 		error ("Can't open help file");
864 	    if (noscroll) doclear ();
865 	    copy_file (helpf);
866 	    close (helpf);
867 	    prompt (filename);
868 	    break;
869 	case 'v':	/* This case should go right before default */
870 	    if (!no_intty) {
871 		kill_line ();
872 		cmdbuf[0] = '+';
873 		scanstr (Currline, &cmdbuf[1]);
874 		pr ("vi "); pr (cmdbuf); putchar (' '); pr (fnames[fnum]);
875 		execute (filename, VI, "vi", cmdbuf, fnames[fnum], 0);
876 		break;
877 	    }
878 	default:
879 	    write (2, &bell, 1);
880 	    break;
881 	}
882 	if (done) break;
883     }
884     putchar ('\r');
885 endsw:
886     inwait = 0;
887     notell++;
888     if (MBIT == RAW && slow_tty) {
889 	otty.sg_flags &= ~MBIT;
890 	stty(2, &otty);
891     }
892     return (retval);
893 }
894 
895 char ch;
896 
897 /*
898  * Execute a colon-prefixed command.
899  * Returns <0 if not a command that should cause
900  * more of the file to be printed.
901  */
902 
903 colon (filename, cmd, nlines)
904 char *filename;
905 int cmd;
906 int nlines;
907 {
908 	if (cmd == 0)
909 		ch = readch ();
910 	else
911 		ch = cmd;
912 	lastcolon = ch;
913 	switch (ch) {
914 	case 'f':
915 		kill_line ();
916 		if (!no_intty)
917 			promptlen = printf ("\"%s\" line %d", fnames[fnum], Currline);
918 		else
919 			promptlen = printf ("[Not a file] line %d", Currline);
920 		fflush (stdout);
921 		return (-1);
922 	case 'n':
923 		if (nlines == 0) {
924 			if (fnum >= nfiles - 1)
925 				end_it ();
926 			nlines++;
927 		}
928 		putchar ('\r');
929 		erase (0);
930 		skipf (nlines);
931 		return (0);
932 	case 'p':
933 		if (no_intty) {
934 			write (2, &bell, 1);
935 			return (-1);
936 		}
937 		putchar ('\r');
938 		erase (0);
939 		if (nlines == 0)
940 			nlines++;
941 		skipf (-nlines);
942 		return (0);
943 	case '!':
944 		do_shell (filename);
945 		return (-1);
946 	case 'q':
947 	case 'Q':
948 		end_it ();
949 	default:
950 		write (2, &bell, 1);
951 		return (-1);
952 	}
953 }
954 
955 /*
956 ** Read a decimal number from the terminal. Set cmd to the non-digit which
957 ** terminates the number.
958 */
959 
960 number(cmd)
961 char *cmd;
962 {
963 	register int i;
964 
965 	i = 0; ch = otty.sg_kill;
966 	for (;;) {
967 		ch = readch ();
968 		if (ch >= '0' && ch <= '9')
969 			i = i*10 + ch - '0';
970 		else if (ch == otty.sg_kill)
971 			i = 0;
972 		else {
973 			*cmd = ch;
974 			break;
975 		}
976 	}
977 	return (i);
978 }
979 
980 do_shell (filename)
981 char *filename;
982 {
983 	char cmdbuf[80];
984 
985 	kill_line ();
986 	pr ("!");
987 	fflush (stdout);
988 	promptlen = 1;
989 	if (lastp)
990 		pr (shell_line);
991 	else {
992 		ttyin (cmdbuf, 78, '!');
993 		if (expand (shell_line, cmdbuf)) {
994 			kill_line ();
995 			promptlen = printf ("!%s", shell_line);
996 		}
997 	}
998 	fflush (stdout);
999 	write (2, "\n", 1);
1000 	promptlen = 0;
1001 	shellp = 1;
1002 	execute (filename, shell, shell, "-c", shell_line, 0);
1003 }
1004 
1005 /*
1006 ** Search for nth ocurrence of regular expression contained in buf in the file
1007 */
1008 
1009 search (buf, file, n)
1010 char buf[];
1011 FILE *file;
1012 register int n;
1013 {
1014     long startline = Ftell (file);
1015     register long line1 = startline;
1016     register long line2 = startline;
1017     register long line3 = startline;
1018     register int lncount;
1019     int saveln, rv, re_exec();
1020     char *s, *re_comp();
1021 
1022     context.line = saveln = Currline;
1023     context.chrctr = startline;
1024     lncount = 0;
1025     if ((s = re_comp (buf)) != 0)
1026 	error (s);
1027     while (!feof (file)) {
1028 	line3 = line2;
1029 	line2 = line1;
1030 	line1 = Ftell (file);
1031 	rdline (file);
1032 	lncount++;
1033 	if ((rv = re_exec (Line)) == 1)
1034 		if (--n == 0) {
1035 		    if (lncount > 3 || (lncount > 1 && no_intty))
1036 			pr ("\n...skipping\n");
1037 		    if (!no_intty) {
1038 			Currline -= (lncount >= 3 ? 3 : lncount);
1039 			Fseek (file, line3);
1040 		    }
1041 		    else {
1042 			kill_line ();
1043 			pr (Line);
1044 			putchar ('\n');
1045 		    }
1046 		    break;
1047 		}
1048 	else if (rv == -1)
1049 	    error ("Regular expression botch");
1050     }
1051     if (feof (file)) {
1052 	if (!no_intty) {
1053 #ifdef V6
1054 	    file->_flag &= ~_IOEOF; /* why doesn't fseek do this ??!!??! */
1055 #endif
1056 	    Currline = saveln;
1057 	    Fseek (file, startline);
1058 	}
1059 	else {
1060 	    pr ("\nPattern not found\n");
1061 	    end_it ();
1062 	}
1063 	error ("Pattern not found");
1064     }
1065 }
1066 
1067 execute (filename, cmd, args)
1068 char *filename;
1069 char *cmd, *args;
1070 {
1071 	int id;
1072 
1073 	fflush (stdout);
1074 	reset_tty ();
1075 	while ((id = fork ()) < 0)
1076 	    sleep (5);
1077 	if (id == 0) {
1078 	    execv (cmd, &args);
1079 	    write (2, "exec failed\n", 12);
1080 	    exit (1);
1081 	}
1082 	signal (SIGINT, SIG_IGN);
1083 	signal (SIGQUIT, SIG_IGN);
1084 #ifdef SIGTSTP
1085 	if (catch_susp)
1086 	    signal(SIGTSTP, SIG_DFL);
1087 #endif
1088 	wait (0);
1089 	signal (SIGINT, end_it);
1090 	signal (SIGQUIT, onquit);
1091 #ifdef SIGTSTP
1092 	if (catch_susp)
1093 	    signal(SIGTSTP, onsusp);
1094 #endif
1095 	set_tty ();
1096 	pr ("------------------------\n");
1097 	prompt (filename);
1098 }
1099 /*
1100 ** Skip n lines in the file f
1101 */
1102 
1103 skiplns (n, f)
1104 register int n;
1105 register FILE *f;
1106 {
1107     register char c;
1108 
1109     while (n > 0) {
1110 	while ((c = Getc (f)) != '\n')
1111 	    if (c == EOF)
1112 		return;
1113 	    n--;
1114 	    Currline++;
1115     }
1116 }
1117 
1118 /*
1119 ** Skip nskip files in the file list (from the command line). Nskip may be
1120 ** negative.
1121 */
1122 
1123 skipf (nskip)
1124 register int nskip;
1125 {
1126     if (nskip == 0) return;
1127     if (nskip > 0) {
1128 	if (fnum + nskip > nfiles - 1)
1129 	    nskip = nfiles - fnum - 1;
1130     }
1131     else if (within)
1132 	++fnum;
1133     fnum += nskip;
1134     if (fnum < 0)
1135 	fnum = 0;
1136     pr ("\n...Skipping ");
1137     pr (nskip > 0 ? "to file " : "back to file ");
1138     pr (fnames[fnum]);
1139     pr ("\n\n");
1140     --fnum;
1141 }
1142 
1143 /*----------------------------- Terminal I/O -------------------------------*/
1144 
1145 initterm ()
1146 {
1147     char	buf[TBUFSIZ];
1148     char	clearbuf[100];
1149     char	*clearptr, *padstr;
1150     char	*getenv();
1151     int		ldisc;
1152 
1153     setbuf(stdout, obuf);
1154     if (!(no_tty = gtty(1, &otty))) {
1155 	if (tgetent(buf, getenv("TERM")) <= 0) {
1156 	    dumb++;
1157 	}
1158 	else {
1159 	    if (((Lpp = tgetnum("li")) < 0) || tgetflag("hc")) {
1160 		hard++;	/* Hard copy terminal */
1161 		Lpp = 24;
1162 	    }
1163 	    if (tailequ (fnames[0], "page") || !hard && tgetflag("ns"))
1164 		noscroll++;
1165 	    if ((Mcol = tgetnum("co")) < 0)
1166 		Mcol = 80;
1167 	    Wrap = tgetflag("am");
1168 	    bad_so = tgetflag ("xs");
1169 	    clearptr = clearbuf;
1170 	    eraseln = tgetstr("ce",&clearptr);
1171 	    Clear = tgetstr("cl", &clearptr);
1172 	    Senter = tgetstr("so", &clearptr);
1173 	    Sexit = tgetstr("se", &clearptr);
1174 	    if (padstr = tgetstr("pc", &clearptr))
1175 		PC = *padstr;
1176 	}
1177 	if ((shell = getenv("SHELL")) == NULL)
1178 	    shell = "/bin/sh";
1179     }
1180     no_intty = gtty(0, &otty);
1181     gtty(2, &otty);
1182     ospeed = otty.sg_ospeed;
1183     slow_tty = ospeed < B1200;
1184     hardtabs =  !(otty.sg_flags & XTABS);
1185     if (!no_tty) {
1186 	otty.sg_flags &= ~ECHO;
1187 	if (MBIT == CBREAK || !slow_tty)
1188 	    otty.sg_flags |= MBIT;
1189     }
1190 }
1191 
1192 readch ()
1193 {
1194 	char ch;
1195 	extern int errno;
1196 
1197 	if (read (2, &ch, 1) <= 0)
1198 		if (errno != EINTR)
1199 			exit(0);
1200 		else
1201 			ch = otty.sg_kill;
1202 	return (ch);
1203 }
1204 
1205 static char BS = '\b';
1206 static char CARAT = '^';
1207 
1208 ttyin (buf, nmax, pchar)
1209 char buf[];
1210 register int nmax;
1211 char pchar;
1212 {
1213     register char *sptr;
1214     register char ch;
1215     register int slash = 0;
1216     int	maxlen;
1217     char cbuf;
1218 
1219     sptr = buf;
1220     maxlen = 0;
1221     while (sptr - buf < nmax) {
1222 	if (promptlen > maxlen) maxlen = promptlen;
1223 	ch = readch ();
1224 	if (ch == '\\') {
1225 	    slash++;
1226 	}
1227 	else if ((ch == otty.sg_erase) && !slash) {
1228 	    if (sptr > buf) {
1229 		--promptlen;
1230 		write (2, &BS, 1);
1231 		--sptr;
1232 		if ((*sptr < ' ' && *sptr != '\n') || *sptr == RUBOUT) {
1233 		    --promptlen;
1234 		    write (2, &BS, 1);
1235 		}
1236 		continue;
1237 	    }
1238 	    else {
1239 		if (!eraseln) promptlen = maxlen;
1240 		longjmp (restore, 1);
1241 	    }
1242 	}
1243 	else if ((ch == otty.sg_kill) && !slash) {
1244 	    if (hard) {
1245 		show (ch);
1246 		putchar ('\n');
1247 		putchar (pchar);
1248 	    }
1249 	    else {
1250 		putchar ('\r');
1251 		putchar (pchar);
1252 		if (eraseln)
1253 		    erase (1);
1254 		promptlen = 1;
1255 	    }
1256 	    sptr = buf;
1257 	    fflush (stdout);
1258 	    continue;
1259 	}
1260 	if (slash && (ch == otty.sg_kill || ch == otty.sg_erase)) {
1261 	    write (2, &BS, 1);
1262 	    --sptr;
1263 	}
1264 	if (ch != '\\')
1265 	    slash = 0;
1266 	*sptr++ = ch;
1267 	if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1268 	    ch += ch == RUBOUT ? -0100 : 0100;
1269 	    write (2, &CARAT, 1);
1270 	    promptlen++;
1271 	}
1272 	cbuf = ch;
1273 	if (ch != '\n' && ch != ESC) {
1274 	    write (2, &cbuf, 1);
1275 	    promptlen++;
1276 	}
1277 	else
1278 	    break;
1279     }
1280     *--sptr = '\0';
1281     if (!eraseln) promptlen = maxlen;
1282     if (sptr - buf >= nmax - 1)
1283 	error ("Line too long");
1284 }
1285 
1286 expand (outbuf, inbuf)
1287 char *outbuf;
1288 char *inbuf;
1289 {
1290     register char *instr;
1291     register char *outstr;
1292     register char ch;
1293     char temp[200];
1294     int changed = 0;
1295 
1296     instr = inbuf;
1297     outstr = temp;
1298     while ((ch = *instr++) != '\0')
1299 	switch (ch) {
1300 	case '%':
1301 	    if (!no_intty) {
1302 		strcpy (outstr, fnames[fnum]);
1303 		outstr += strlen (fnames[fnum]);
1304 		changed++;
1305 	    }
1306 	    else
1307 		*outstr++ = ch;
1308 	    break;
1309 	case '!':
1310 	    if (!shellp)
1311 		error ("No previous command to substitute for");
1312 	    strcpy (outstr, shell_line);
1313 	    outstr += strlen (shell_line);
1314 	    changed++;
1315 	    break;
1316 	case '\\':
1317 	    if (*instr == '%' || *instr == '!') {
1318 		*outstr++ = *instr++;
1319 		break;
1320 	    }
1321 	default:
1322 	    *outstr++ = ch;
1323 	}
1324     *outstr++ = '\0';
1325     strcpy (outbuf, temp);
1326     return (changed);
1327 }
1328 
1329 show (ch)
1330 register char ch;
1331 {
1332     char cbuf;
1333 
1334     if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
1335 	ch += ch == RUBOUT ? -0100 : 0100;
1336 	write (2, &CARAT, 1);
1337 	promptlen++;
1338     }
1339     cbuf = ch;
1340     write (2, &cbuf, 1);
1341     promptlen++;
1342 }
1343 
1344 error (mess)
1345 char *mess;
1346 {
1347     kill_line ();
1348     promptlen += strlen (mess);
1349     if (Senter && Sexit) {
1350 	tputs (Senter, 1, putch);
1351 	pr(mess);
1352 	tputs (Sexit, 1, putch);
1353     }
1354     else
1355 	pr (mess);
1356     fflush(stdout);
1357     errors++;
1358     longjmp (restore, 1);
1359 }
1360 
1361 
1362 set_tty ()
1363 {
1364 	otty.sg_flags |= MBIT;
1365 	otty.sg_flags &= ~ECHO;
1366 	stty(2, &otty);
1367 }
1368 
1369 reset_tty ()
1370 {
1371     otty.sg_flags |= ECHO;
1372     otty.sg_flags &= ~MBIT;
1373     stty(2, &otty);
1374 }
1375 
1376 rdline (f)
1377 register FILE *f;
1378 {
1379     register char c;
1380     register char *p;
1381 
1382     p = Line;
1383     while ((c = Getc (f)) != '\n' && c != EOF && p - Line < LINSIZ - 1)
1384 	*p++ = c;
1385     if (c == '\n')
1386 	Currline++;
1387     *p = '\0';
1388 }
1389 
1390 /* Come here when we get a suspend signal from the terminal */
1391 
1392 #ifdef SIGTSTP
1393 onsusp ()
1394 {
1395     reset_tty ();
1396     fflush (stdout);
1397     /* Send the TSTP signal to suspend our process group */
1398     kill (0, SIGTSTP);
1399     /* Pause for station break */
1400 
1401     /* We're back */
1402     signal (SIGTSTP, onsusp);
1403     set_tty ();
1404     if (inwait)
1405 	    longjmp (restore);
1406 }
1407 #endif
1408