more.c

早期freebsd实现

		putchar ('\r');
		erase (0);
		skipf (nlines);
		return (0);
	case 'p':
		if (no_intty) {
			write (2, &bell, 1);
			return (-1);
		}
		putchar ('\r');
		erase (0);
		if (nlines == 0)
			nlines++;
		skipf (-nlines);
		return (0);
	case '!':
		do_shell (filename);
		return (-1);
	case 'q':
	case 'Q':
		end_it ();
	default:
		write (2, &bell, 1);
		return (-1);
	}
}

/*
** Read a decimal number from the terminal. Set cmd to the non-digit which
** terminates the number.
*/

number(cmd)
char *cmd;
{
	register int i;

	i = 0; ch = otty.sg_kill;
	for (;;) {
		ch = readch ();
		if (ch >= '0' && ch <= '9')
			i = i*10 + ch - '0';
		else if (ch == otty.sg_kill)
			i = 0;
		else {
			*cmd = ch;
			break;
		}
	}
	return (i);
}

do_shell (filename)
char *filename;
{
	char cmdbuf[80];

	kill_line ();
	pr ("!");
	fflush (stdout);
	promptlen = 1;
	if (lastp)
		pr (shell_line);
	else {
		ttyin (cmdbuf, 78, '!');
		if (expand (shell_line, cmdbuf)) {
			kill_line ();
			promptlen = prtf ("!%s", shell_line);
		}
	}
	fflush (stdout);
	write (2, "\n", 1);
	promptlen = 0;
	shellp = 1;
	execute (filename, shell, shell, "-c", shell_line, 0);
}

/*
** Search for nth ocurrence of regular expression contained in buf in the file
*/

search (buf, file, n)
char buf[];
FILE *file;
register int n;
{
    long startline = Ftell (file);
    register long line1 = startline;
    register long line2 = startline;
    register long line3 = startline;
    register int lncount;
    int saveln, rv, re_exec();
    char *s, *re_comp();

    context.line = saveln = Currline;
    context.chrctr = startline;
    lncount = 0;
    if ((s = re_comp (buf)) != 0)
	error (s);
    while (!feof (file)) {
	line3 = line2;
	line2 = line1;
	line1 = Ftell (file);
	rdline (file);
	lncount++;
	if ((rv = re_exec (Line)) == 1)
		if (--n == 0) {
		    if (lncount > 3 || (lncount > 1 && no_intty))
		    {
			pr ("\n");
			if (clreol)
			    cleareol ();
			pr("...skipping\n");
		    }
		    if (!no_intty) {
			Currline -= (lncount >= 3 ? 3 : lncount);
			Fseek (file, line3);
			if (noscroll)
			    if (clreol) {
				home ();
				cleareol ();
			    }
			    else
				doclear ();
		    }
		    else {
			kill_line ();
			if (noscroll)
			    if (clreol) {
			        home ();
			        cleareol ();
			    }
			    else
				doclear ();
			pr (Line);
			putchar ('\n');
		    }
		    break;
		}
	else if (rv == -1)
	    error ("Regular expression botch");
    }
    if (feof (file)) {
	if (!no_intty) {
	/*    file->_flag &= ~_IOEOF; /* why doesn't fseek do this ??!!??! */
	    Currline = saveln;
	    Fseek (file, startline);
	}
	else {
	    pr ("\nPattern not found\n");
	    end_it ();
	}
	error ("Pattern not found");
    }
}

/*VARARGS2*/
execute (filename, cmd, va_alist)
char *filename;
char *cmd;
va_dcl
{
	int id;
	int n;
	va_list argp;

	fflush (stdout);
	reset_tty ();
	for (n = 10; (id = fork ()) < 0 && n > 0; n--)
	    sleep (5);
	if (id == 0) {
	    if (!isatty(0)) {
		close(0);
		open("/dev/tty", 0);
	    }
	    va_start(argp);
	    execv (cmd, argp);
	    write (2, "exec failed\n", 12);
	    exit (1);
	    va_end(argp);	/* balance {}'s for some UNIX's */
	}
	if (id > 0) {
	    signal (SIGINT, SIG_IGN);
	    signal (SIGQUIT, SIG_IGN);
	    if (catch_susp)
		signal(SIGTSTP, SIG_DFL);
	    while (wait(0) > 0);
	    signal (SIGINT, end_it);
	    signal (SIGQUIT, onquit);
	    if (catch_susp)
		signal(SIGTSTP, onsusp);
	} else
	    write(2, "can't fork\n", 11);
	set_tty ();
	pr ("------------------------\n");
	prompt (filename);
}
/*
** Skip n lines in the file f
*/

skiplns (n, f)
register int n;
register FILE *f;
{
    register char c;

    while (n > 0) {
	while ((c = Getc (f)) != '\n')
	    if (c == EOF)
		return;
	    n--;
	    Currline++;
    }
}

/*
** Skip nskip files in the file list (from the command line). Nskip may be
** negative.
*/

skipf (nskip)
register int nskip;
{
    if (nskip == 0) return;
    if (nskip > 0) {
	if (fnum + nskip > nfiles - 1)
	    nskip = nfiles - fnum - 1;
    }
    else if (within)
	++fnum;
    fnum += nskip;
    if (fnum < 0)
	fnum = 0;
    pr ("\n...Skipping ");
    pr ("\n");
    if (clreol)
	cleareol ();
    pr ("...Skipping ");
    pr (nskip > 0 ? "to file " : "back to file ");
    pr (fnames[fnum]);
    pr ("\n");
    if (clreol)
	cleareol ();
    pr ("\n");
    --fnum;
}

/*----------------------------- Terminal I/O -------------------------------*/

initterm ()
{
    char	buf[TBUFSIZ];
    static char	clearbuf[TBUFSIZ];
    char	*clearptr, *padstr;
    int		ldisc;
    int		lmode;
    char	*term;
    int		tgrp;
    struct winsize win;
    char	*tgoto();

retry:
    if (!(no_tty = ioctl(fileno(stdout), TIOCGETP, &otty))) {
	if (ioctl(fileno(stdout), TIOCLGET, &lmode) < 0) {
	    perror("TIOCLGET");
	    exit(1);
	}
	docrterase = ((lmode & LCRTERA) != 0);
	docrtkill = ((lmode & LCRTKIL) != 0);
	/*
	 * Wait until we're in the foreground before we save the
	 * the terminal modes.
	 */
	if (ioctl(fileno(stdout), TIOCGPGRP, &tgrp) < 0) {
	    perror("TIOCGPGRP");
	    exit(1);
	}
	if (tgrp != getpgrp(0)) {
	    kill(0, SIGTTOU);
	    goto retry;
	}
	if ((term = getenv("TERM")) == 0 || tgetent(buf, term) <= 0) {
	    dumb++; ul_opt = 0;
	}
	else {
	    if (ioctl(fileno(stdout), TIOCGWINSZ, &win) < 0) {
		Lpp = tgetnum("li");
		Mcol = tgetnum("co");
	    } else {
		if ((Lpp = win.ws_row) == 0)
		    Lpp = tgetnum("li");
		if ((Mcol = win.ws_col) == 0)
		    Mcol = tgetnum("co");
	    }
	    if ((Lpp <= 0) || tgetflag("hc")) {
		hard++;	/* Hard copy terminal */
		Lpp = 24;
	    }
	    if (tgetflag("xn"))
		eatnl++; /* Eat newline at last column + 1; dec, concept */
	    if (Mcol <= 0)
		Mcol = 80;

	    if (tailequ (fnames[0], "page") || !hard && tgetflag("ns"))
		noscroll++;
	    Wrap = tgetflag("am");
	    bad_so = tgetflag ("xs");
	    clearptr = clearbuf;
	    eraseln = tgetstr("ce",&clearptr);
	    Clear = tgetstr("cl", &clearptr);
	    Senter = tgetstr("so", &clearptr);
	    Sexit = tgetstr("se", &clearptr);
	    if ((soglitch = tgetnum("sg")) < 0)
		soglitch = 0;

	    /*
	     *  Set up for underlining:  some terminals don't need it;
	     *  others have start/stop sequences, still others have an
	     *  underline char sequence which is assumed to move the
	     *  cursor forward one character.  If underline sequence
	     *  isn't available, settle for standout sequence.
	     */

	    if (tgetflag("ul") || tgetflag("os"))
		ul_opt = 0;
	    if ((chUL = tgetstr("uc", &clearptr)) == NULL )
		chUL = "";
	    if (((ULenter = tgetstr("us", &clearptr)) == NULL ||
	         (ULexit = tgetstr("ue", &clearptr)) == NULL) && !*chUL) {
	        if ((ULenter = Senter) == NULL || (ULexit = Sexit) == NULL) {
			ULenter = "";
			ULexit = "";
		} else
			ulglitch = soglitch;
	    } else {
		if ((ulglitch = tgetnum("ug")) < 0)
		    ulglitch = 0;
	    }

	    if (padstr = tgetstr("pc", &clearptr))
		PC = *padstr;
	    Home = tgetstr("ho",&clearptr);
	    if (Home == 0 || *Home == '\0')
	    {
		if ((cursorm = tgetstr("cm", &clearptr)) != NULL) {
		    strcpy(cursorhome, tgoto(cursorm, 0, 0));
		    Home = cursorhome;
	       }
	    }
	    EodClr = tgetstr("cd", &clearptr);
	    if ((chBS = tgetstr("bc", &clearptr)) == NULL)
		chBS = "\b";

	}
	if ((shell = getenv("SHELL")) == NULL)
	    shell = "/bin/sh";
    }
    no_intty = ioctl(fileno(stdin), TIOCGETP, &otty);
    (void)ioctl(fileno(stderr), TIOCGETP, &otty);
    savetty = otty;
    ospeed = otty.sg_ospeed;
    slow_tty = ospeed < B1200;
    hardtabs = (otty.sg_flags & TBDELAY) != XTABS;
    if (!no_tty) {
	otty.sg_flags &= ~ECHO;
	if (MBIT == CBREAK || !slow_tty)
	    otty.sg_flags |= MBIT;
    }
}

readch ()
{
	char ch;
	extern int errno;

	errno = 0;
	if (read (2, &ch, 1) <= 0)
		if (errno != EINTR)
			end_it();
		else
			ch = otty.sg_kill;
	return (ch);
}

static char BS = '\b';
static char *BSB = "\b \b";
static char CARAT = '^';
#define ERASEONECHAR \
    if (docrterase) \
	write (2, BSB, sizeof(BSB)); \
    else \
	write (2, &BS, sizeof(BS));

ttyin (buf, nmax, pchar)
char buf[];
register int nmax;
char pchar;
{
    register char *sptr;
    register char ch;
    register int slash = 0;
    int	maxlen;
    char cbuf;

    sptr = buf;
    maxlen = 0;
    while (sptr - buf < nmax) {
	if (promptlen > maxlen) maxlen = promptlen;
	ch = readch ();
	if (ch == '\\') {
	    slash++;
	}
	else if ((ch == otty.sg_erase) && !slash) {
	    if (sptr > buf) {
		--promptlen;
		ERASEONECHAR
		--sptr;
		if ((*sptr < ' ' && *sptr != '\n') || *sptr == RUBOUT) {
		    --promptlen;
		    ERASEONECHAR
		}
		continue;
	    }
	    else {
		if (!eraseln) promptlen = maxlen;
		longjmp (restore, 1);
	    }
	}
	else if ((ch == otty.sg_kill) && !slash) {
	    if (hard) {
		show (ch);
		putchar ('\n');
		putchar (pchar);
	    }
	    else {
		putchar ('\r');
		putchar (pchar);
		if (eraseln)
		    erase (1);
		else if (docrtkill)
		    while (promptlen-- > 1)
			write (2, BSB, sizeof(BSB));
		promptlen = 1;
	    }
	    sptr = buf;
	    fflush (stdout);
	    continue;
	}
	if (slash && (ch == otty.sg_kill || ch == otty.sg_erase)) {
	    ERASEONECHAR
	    --sptr;
	}
	if (ch != '\\')
	    slash = 0;
	*sptr++ = ch;
	if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
	    ch += ch == RUBOUT ? -0100 : 0100;
	    write (2, &CARAT, 1);
	    promptlen++;
	}
	cbuf = ch;
	if (ch != '\n' && ch != ESC) {
	    write (2, &cbuf, 1);
	    promptlen++;
	}
	else
	    break;
    }
    *--sptr = '\0';
    if (!eraseln) promptlen = maxlen;
    if (sptr - buf >= nmax - 1)
	error ("Line too long");
}

expand (outbuf, inbuf)
char *outbuf;
char *inbuf;
{
    register char *instr;
    register char *outstr;
    register char ch;
    char temp[200];
    int changed = 0;

    instr = inbuf;
    outstr = temp;
    while ((ch = *instr++) != '\0')
	switch (ch) {
	case '%':
	    if (!no_intty) {
		strcpy (outstr, fnames[fnum]);
		outstr += strlen (fnames[fnum]);
		changed++;
	    }
	    else
		*outstr++ = ch;
	    break;
	case '!':
	    if (!shellp)
		error ("No previous command to substitute for");
	    strcpy (outstr, shell_line);
	    outstr += strlen (shell_line);
	    changed++;
	    break;
	case '\\':
	    if (*instr == '%' || *instr == '!') {
		*outstr++ = *instr++;
		break;
	    }
	default:
	    *outstr++ = ch;
	}
    *outstr++ = '\0';
    strcpy (outbuf, temp);
    return (changed);
}

show (ch)
register char ch;
{
    char cbuf;

    if ((ch < ' ' && ch != '\n' && ch != ESC) || ch == RUBOUT) {
	ch += ch == RUBOUT ? -0100 : 0100;
	write (2, &CARAT, 1);
	promptlen++;
    }
    cbuf = ch;
    write (2, &cbuf, 1);
    promptlen++;
}

error (mess)
char *mess;
{
    if (clreol)
	cleareol ();
    else
	kill_line ();
    promptlen += strlen (mess);
    if (Senter && Sexit) {
	tputs (Senter, 1, putch);
	pr(mess);
	tputs (Sexit, 1, putch);
    }
    else
	pr (mess);
    fflush(stdout);
    errors++;
    longjmp (restore, 1);
}


set_tty ()
{
	otty.sg_flags |= MBIT;
	otty.sg_flags &= ~ECHO;
	stty(fileno(stderr), &otty);
}

reset_tty ()
{
    if (no_tty)
	return;
    if (pstate) {
	tputs(ULexit, 1, putch);
	fflush(stdout);
	pstate = 0;
    }
    otty.sg_flags |= ECHO;
    otty.sg_flags &= ~MBIT;
    stty(fileno(stderr), &savetty);
}

rdline (f)
register FILE *f;
{
    register char c;
    register char *p;

    p = Line;
    while ((c = Getc (f)) != '\n' && c != EOF && p - Line < LINSIZ - 1)
	*p++ = c;
    if (c == '\n')
	Currline++;
    *p = '\0';
}

/* Come here when we get a suspend signal from the terminal */

void
onsusp ()
{
    /* ignore SIGTTOU so we don't get stopped if csh grabs the tty */
    signal(SIGTTOU, SIG_IGN);
    reset_tty ();
    fflush (stdout);
    signal(SIGTTOU, SIG_DFL);
    /* Send the TSTP signal to suspend our process group */
    signal(SIGTSTP, SIG_DFL);
    sigsetmask(0);
    kill (0, SIGTSTP);
    /* Pause for station break */

    /* We're back */
    signal (SIGTSTP, onsusp);
    set_tty ();
    if (inwait)
	    longjmp (restore, 1);
}