lex.c

早期freebsd实现

	if (*ar < *al) {
	    *ar = 0;
	    *al = 1;
	    return (1);
	}
	break;

    default:
	if (Isdigit(c)) {
	    i = 0;
	    while (Isdigit(c)) {
		i = i * 10 + c - '0';
		c = getC(0);
	    }
	    if (i < 0)
		i = dol + 1;
	    if (*al < 0)
		*al = i;
	    *ar = i;
	}
	else if (*al < 0)
	    *al = 0, *ar = dol;
	else
	    *ar = dol - 1;
	unreadc(c);
	break;
    }
    if (first) {
	c = getC(0);
	unreadc(c);
	if (any("-$*", c))
	    return (1);
    }
    if (*al > *ar || *ar > dol) {
	seterror(ERR_BADBANGARG);
	return (0);
    }
    return (1);

}

static struct wordent *
gethent(sc)
    int     sc;
{
    register struct Hist *hp;
    register Char *np;
    register int c;
    int     event;
    bool    back = 0;

    c = sc == HISTSUB ? HIST : getC(0);
    if (c == HIST) {
	if (alhistp)
	    return (alhistp);
	event = eventno;
    }
    else
	switch (c) {

	case ':':
	case '^':
	case '$':
	case '*':
	case '%':
	    ungetC(c);
	    if (lastev == eventno && alhistp)
		return (alhistp);
	    event = lastev;
	    break;

	case '#':		/* !# is command being typed in (mrh) */
	    if (--hleft == 0) {
		seterror(ERR_HISTLOOP);
		return (0);
	    }
	    else
		return (&paraml);
	    /* NOTREACHED */

	case '-':
	    back = 1;
	    c = getC(0);
	    /* FALLSTHROUGH */

	default:
	    if (any("(=~", c)) {
		unreadc(c);
		ungetC(HIST);
		return (0);
	    }
	    np = lhsb;
	    event = 0;
	    while (!cmap(c, _ESC | _META | _QF | _QB) && !any("${}:", c)) {
		if (event != -1 && Isdigit(c))
		    event = event * 10 + c - '0';
		else
		    event = -1;
		if (np < &lhsb[sizeof(lhsb) / sizeof(Char) - 2])
		    *np++ = c;
		c = getC(0);
	    }
	    unreadc(c);
	    if (np == lhsb) {
		ungetC(HIST);
		return (0);
	    }
	    *np++ = 0;
	    if (event != -1) {
		/*
		 * History had only digits
		 */
		if (back)
		    event = eventno + (alhistp == 0) - (event ? event : 0);
		break;
	    }
	    hp = findev(lhsb, 0);
	    if (hp)
		lastev = hp->Hnum;
	    return (&hp->Hlex);

	case '?':
	    np = lhsb;
	    for (;;) {
		c = getC(0);
		if (c == '\n') {
		    unreadc(c);
		    break;
		}
		if (c == '?')
		    break;
		if (np < &lhsb[sizeof(lhsb) / sizeof(Char) - 2])
		    *np++ = c;
	    }
	    if (np == lhsb) {
		if (lhsb[0] == 0) {
		    seterror(ERR_NOSEARCH);
		    return (0);
		}
	    }
	    else
		*np++ = 0;
	    hp = findev(lhsb, 1);
	    if (hp)
		lastev = hp->Hnum;
	    return (&hp->Hlex);
	}

    for (hp = Histlist.Hnext; hp; hp = hp->Hnext)
	if (hp->Hnum == event) {
	    hp->Href = eventno;
	    lastev = hp->Hnum;
	    return (&hp->Hlex);
	}
    np = putn(event);
    seterror(ERR_NOEVENT, vis_str(np));
    return (0);
}

static struct Hist *
findev(cp, anyarg)
    Char   *cp;
    bool    anyarg;
{
    register struct Hist *hp;

    for (hp = Histlist.Hnext; hp; hp = hp->Hnext) {
	Char   *dp;
	register Char *p, *q;
	register struct wordent *lp = hp->Hlex.next;
	int     argno = 0;

	/*
	 * The entries added by alias substitution don't have a newline but do
	 * have a negative event number. Savehist() trims off these entries,
	 * but it happens before alias expansion, too early to delete those
	 * from the previous command.
	 */
	if (hp->Hnum < 0)
	    continue;
	if (lp->word[0] == '\n')
	    continue;
	if (!anyarg) {
	    p = cp;
	    q = lp->word;
	    do
		if (!*p)
		    return (hp);
	    while (*p++ == *q++);
	    continue;
	}
	do {
	    for (dp = lp->word; *dp; dp++) {
		p = cp;
		q = dp;
		do
		    if (!*p) {
			quesarg = argno;
			return (hp);
		    }
		while (*p++ == *q++);
	    }
	    lp = lp->next;
	    argno++;
	} while (lp->word[0] != '\n');
    }
    seterror(ERR_NOEVENT, vis_str(cp));
    return (0);
}


static void
setexclp(cp)
    register Char *cp;
{
    if (cp && cp[0] == '\n')
	return;
    exclp = cp;
}

void
unreadc(c)
    int    c;
{
    peekread = c;
}

int
readc(wanteof)
    bool    wanteof;
{
    register int c;
    static  sincereal;

    aret = F_SEEK;
    if ((c = peekread) != '\0') {
	peekread = 0;
	return (c);
    }
top:
    aret = F_SEEK;
    if (alvecp) {
	aret = A_SEEK;
	if ((c = *alvecp++) != '\0')
	    return (c);
	if (alvec && *alvec) {
		alvecp = *alvec++;
		return (' ');
	}
	else {
	    aret = F_SEEK;
	    alvecp = NULL;
	    return('\n');
	}
    }
    if (alvec) {
	if ((alvecp = *alvec) != '\0') {
	    alvec++;
	    goto top;
	}
	/* Infinite source! */
	return ('\n');
    }
    if (evalp) {
	aret = E_SEEK;
	if ((c = *evalp++) != '\0')
	    return (c);
	if (evalvec && *evalvec) {
	    evalp = *evalvec++;
	    return (' ');
	}
	aret = F_SEEK;
	evalp = 0;
    }
    if (evalvec) {
	if (evalvec == (Char **) 1) {
	    doneinp = 1;
	    reset();
	}
	if ((evalp = *evalvec) != '\0') {
	    evalvec++;
	    goto top;
	}
	evalvec = (Char **) 1;
	return ('\n');
    }
    do {
	if (arginp == (Char *) 1 || onelflg == 1) {
	    if (wanteof)
		return (-1);
	    exitstat();
	}
	if (arginp) {
	    if ((c = *arginp++) == 0) {
		arginp = (Char *) 1;
		return ('\n');
	    }
	    return (c);
	}
reread:
	c = bgetc();
	if (c < 0) {
	    struct termios tty;
	    if (wanteof)
		return (-1);
	    /* was isatty but raw with ignoreeof yields problems */
	    if (tcgetattr(SHIN, &tty) == 0 && (tty.c_lflag & ICANON))
	    {
		/* was 'short' for FILEC */
		int     ctpgrp;

		if (++sincereal > 25)
		    goto oops;
		if (tpgrp != -1 &&
		    (ctpgrp = tcgetpgrp(FSHTTY)) != -1 &&
		    tpgrp != ctpgrp) {
		    (void) tcsetpgrp(FSHTTY, tpgrp);
		    (void) killpg((pid_t) ctpgrp, SIGHUP);
		    (void) fprintf(csherr, "Reset tty pgrp from %d to %d\n",
				   ctpgrp, tpgrp);
		    goto reread;
		}
		if (adrof(STRignoreeof)) {
		    if (loginsh)
			(void) fprintf(csherr,"\nUse \"logout\" to logout.\n");
		    else
			(void) fprintf(csherr,"\nUse \"exit\" to leave csh.\n");
		    reset();
		}
		if (chkstop == 0)
		    panystop(1);
	    }
    oops:
	    doneinp = 1;
	    reset();
	}
	sincereal = 0;
	if (c == '\n' && onelflg)
	    onelflg--;
    } while (c == 0);
    return (c);
}

static int
bgetc()
{
    register int buf, off, c;

#ifdef FILEC
    register int numleft = 0, roomleft;
    Char    ttyline[BUFSIZ];
#endif
    char    tbuf[BUFSIZ + 1];

    if (cantell) {
	if (fseekp < fbobp || fseekp > feobp) {
	    fbobp = feobp = fseekp;
	    (void) lseek(SHIN, fseekp, L_SET);
	}
	if (fseekp == feobp) {
	    int     i;

	    fbobp = feobp;
	    do
		c = read(SHIN, tbuf, BUFSIZ);
	    while (c < 0 && errno == EINTR);
	    if (c <= 0)
		return (-1);
	    for (i = 0; i < c; i++)
		fbuf[0][i] = (unsigned char) tbuf[i];
	    feobp += c;
	}
	c = fbuf[0][fseekp - fbobp];
	fseekp++;
	return (c);
    }

again:
    buf = (int) fseekp / BUFSIZ;
    if (buf >= fblocks) {
	register Char **nfbuf =
	(Char **) xcalloc((size_t) (fblocks + 2),
			  sizeof(Char **));

	if (fbuf) {
	    (void) blkcpy(nfbuf, fbuf);
	    xfree((ptr_t) fbuf);
	}
	fbuf = nfbuf;
	fbuf[fblocks] = (Char *) xcalloc(BUFSIZ, sizeof(Char));
	fblocks++;
	if (!intty)
	    goto again;
    }
    if (fseekp >= feobp) {
	buf = (int) feobp / BUFSIZ;
	off = (int) feobp % BUFSIZ;
	roomleft = BUFSIZ - off;

#ifdef FILEC
	roomleft = BUFSIZ - off;
	for (;;) {
	    if (filec && intty) {
		c = numleft ? numleft : tenex(ttyline, BUFSIZ);
		if (c > roomleft) {
		    /* start with fresh buffer */
		    feobp = fseekp = fblocks * BUFSIZ;
		    numleft = c;
		    goto again;
		}
		if (c > 0)
		    bcopy(ttyline, fbuf[buf] + off, c * sizeof(Char));
		numleft = 0;
	    }
	    else {
#endif
		c = read(SHIN, tbuf, roomleft);
		if (c > 0) {
		    int     i;
		    Char   *ptr = fbuf[buf] + off;

		    for (i = 0; i < c; i++)
			ptr[i] = (unsigned char) tbuf[i];
		}
#ifdef FILEC
	    }
#endif
	    if (c >= 0)
		break;
	    if (errno == EWOULDBLOCK) {
		int     off = 0;

		(void) ioctl(SHIN, FIONBIO, (ioctl_t) & off);
	    }
	    else if (errno != EINTR)
		break;
	}
	if (c <= 0)
	    return (-1);
	feobp += c;
#ifndef FILEC
	goto again;
#else
	if (filec && !intty)
	    goto again;
#endif
    }
    c = fbuf[buf][(int) fseekp % BUFSIZ];
    fseekp++;
    return (c);
}

static void
bfree()
{
    register int sb, i;

    if (cantell)
	return;
    if (whyles)
	return;
    sb = (int) (fseekp - 1) / BUFSIZ;
    if (sb > 0) {
	for (i = 0; i < sb; i++)
	    xfree((ptr_t) fbuf[i]);
	(void) blkcpy(fbuf, &fbuf[sb]);
	fseekp -= BUFSIZ * sb;
	feobp -= BUFSIZ * sb;
	fblocks -= sb;
    }
}

void
bseek(l)
    struct Ain   *l;
{
    switch (aret = l->type) {
    case E_SEEK:
	evalvec = l->a_seek;
	evalp = l->c_seek;
	return;
    case A_SEEK:
	alvec = l->a_seek;
	alvecp = l->c_seek;
	return;
    case F_SEEK:
	fseekp = l->f_seek;
	return;
    default:
	(void) fprintf(csherr, "Bad seek type %d\n", aret);
	abort();
    }
}

void
btell(l)
    struct Ain *l;
{
    switch (l->type = aret) {
    case E_SEEK:
	l->a_seek = evalvec;
	l->c_seek = evalp;
	return;
    case A_SEEK:
	l->a_seek = alvec;
	l->c_seek = alvecp;
	return;
    case F_SEEK:
	l->f_seek = fseekp;
	l->a_seek = NULL;
	return;
    default:
	(void) fprintf(csherr, "Bad seek type %d\n", aret);
	abort();
    }
}

void
btoeof()
{
    (void) lseek(SHIN, (off_t) 0, L_XTND);
    aret = F_SEEK;
    fseekp = feobp;
    alvec = NULL;
    alvecp = NULL;
    evalvec = NULL;
    evalp = NULL;
    wfree();
    bfree();
}

void
settell()
{
    cantell = 0;
    if (arginp || onelflg || intty)
	return;
    if (lseek(SHIN, (off_t) 0, L_INCR) < 0 || errno == ESPIPE)
	return;
    fbuf = (Char **) xcalloc(2, sizeof(Char **));
    fblocks = 1;
    fbuf[0] = (Char *) xcalloc(BUFSIZ, sizeof(Char));
    fseekp = fbobp = feobp = lseek(SHIN, (off_t) 0, L_INCR);
    cantell = 1;
}