Add original unix v6

source/s1/grep.c

@@ -0,0 +1,342 @@
+#
+/*
+ * grep -- print lines matching (or not matching) a pattern
+ *
+ */
+
+#define	CCHR	2
+#define	CDOT	4
+#define	CCL	6
+#define	NCCL	8
+#define	CDOL	10
+#define	CEOF	11
+
+#define	STAR	01
+
+#define	LBSIZE	256
+#define	ESIZE	256
+
+char	ibuf[512];
+char	expbuf[ESIZE];
+int	lnum[2];
+char	linebuf[LBSIZE+1];
+int	bflag;
+int	nflag;
+int	cflag;
+int	vflag;
+int	nfile;
+int	circf;
+int	blkno;
+int	tln[2];
+
+main(argc, argv)
+char **argv;
+{
+	extern fout;
+
+	fout = dup(1);
+	flush();
+	while (--argc > 0 && (++argv)[0][0]=='-')
+		switch (argv[0][1]) {
+
+		case 'v':
+			vflag++;
+			continue;
+
+		case 'b':
+			bflag++;
+			continue;
+
+		case 'c':
+			cflag++;
+			continue;
+
+		case 'n':
+			nflag++;
+			continue;
+
+		default:
+			printf2("Unknown flag\n");
+			continue;
+		}
+	if (argc<=0)
+		exit(2);
+	compile(*argv);
+	nfile = --argc;
+	if (argc<=0)
+		execute(0);
+	else while (--argc >= 0) {
+		argv++;
+		execute(*argv);
+	}
+	flush();
+	exit(0);
+}
+
+compile(astr)
+char *astr;
+{
+	register c;
+	register char *ep, *sp;
+	char *lastep;
+	int cclcnt;
+
+	ep = expbuf;
+	sp = astr;
+	if (*sp == '^') {
+		circf++;
+		sp++;
+	}
+	for (;;) {
+		if (ep >= &expbuf[ESIZE])
+			goto cerror;
+		if ((c = *sp++) != '*')
+			lastep = ep;
+		switch (c) {
+
+		case '\0':
+			*ep++ = CEOF;
+			return;
+
+		case '.':
+			*ep++ = CDOT;
+			continue;
+
+		case '*':
+			if (lastep==0)
+				goto defchar;
+			*lastep =| STAR;
+			continue;
+
+		case '$':
+			if (*sp != '\0')
+				goto defchar;
+			*ep++ = CDOL;
+			continue;
+
+		case '[':
+			*ep++ = CCL;
+			*ep++ = 0;
+			cclcnt = 1;
+			if ((c = *sp++) == '^') {
+				c = *sp++;
+				ep[-2] = NCCL;
+			}
+			do {
+				*ep++ = c;
+				cclcnt++;
+				if (c=='\0' || ep >= &expbuf[ESIZE])
+					goto cerror;
+			} while ((c = *sp++) != ']');
+			lastep[1] = cclcnt;
+			continue;
+
+		case '\\':
+			if ((c = *sp++) == '\0')
+				goto cerror;
+		defchar:
+		default:
+			*ep++ = CCHR;
+			*ep++ = c;
+		}
+	}
+    cerror:
+	printf2("RE error\n");
+}
+
+execute(file)
+{
+	register char *p1, *p2;
+	register c;
+	int f;
+	char *ebp, *cbp;
+
+	if (file) {
+		if ((f = open(file, 0)) < 0) {
+			printf2("Can't open %s\n", file);
+		}
+	} else
+		f = 0;
+	ebp = ibuf;
+	cbp = ibuf;
+	lnum[0] = 0;
+	lnum[1] = 0;
+	tln[0] = 0;
+	tln[1] = 0;
+	blkno = -1;
+	for (;;) {
+		if ((++lnum[1])==0)
+			lnum[1]++;
+		if((lnum[1]&0377) == 0)
+			flush();
+		p1 = linebuf;
+		p2 = cbp;
+		for (;;) {
+			if (p2 >= ebp) {
+				if ((c = read(f, ibuf, 512)) <= 0) {
+					close(f);
+					if (cflag) {
+						if (nfile > 1)
+							printf("%s:", file);
+						p1 = locv(tln[0],tln[1]);
+						printf("%s\n", p1);
+					}
+					return;
+				}
+				blkno++;
+				p2 = ibuf;
+				ebp = ibuf+c;
+			}
+			if ((c = *p2++) == '\n')
+				break;
+			if(c)
+			if (p1 < &linebuf[LBSIZE-1])
+				*p1++ = c;
+		}
+		*p1++ = 0;
+		cbp = p2;
+		p1 = linebuf;
+		p2 = expbuf;
+		if (circf) {
+			if (advance(p1, p2))
+				goto found;
+			goto nfound;
+		}
+		/* fast check for first character */
+		if (*p2==CCHR) {
+			c = p2[1];
+			do {
+				if (*p1!=c)
+					continue;
+				if (advance(p1, p2))
+					goto found;
+			} while (*p1++);
+			goto nfound;
+		}
+		/* regular algorithm */
+		do {
+			if (advance(p1, p2))
+				goto found;
+		} while (*p1++);
+	nfound:
+		if (vflag)
+			succeed(file);
+		continue;
+	found:
+		if (vflag==0)
+			succeed(file);
+	}
+}
+
+advance(alp, aep)
+{
+	register char *lp, *ep, *curlp;
+	char *nextep;
+
+	lp = alp;
+	ep = aep;
+	for (;;) switch (*ep++) {
+
+	case CCHR:
+		if (*ep++ == *lp++)
+			continue;
+		return(0);
+
+	case CDOT:
+		if (*lp++)
+			continue;
+		return(0);
+
+	case CDOL:
+		if (*lp==0)
+			continue;
+		return(0);
+
+	case CEOF:
+		return(1);
+
+	case CCL:
+		if (cclass(ep, *lp++, 1)) {
+			ep =+ *ep;
+			continue;
+		}
+		return(0);
+
+	case NCCL:
+		if (cclass(ep, *lp++, 0)) {
+			ep =+ *ep;
+			continue;
+		}
+		return(0);
+
+	case CDOT|STAR:
+		curlp = lp;
+		while (*lp++);
+		goto star;
+
+	case CCHR|STAR:
+		curlp = lp;
+		while (*lp++ == *ep);
+		ep++;
+		goto star;
+
+	case CCL|STAR:
+	case NCCL|STAR:
+		curlp = lp;
+		while (cclass(ep, *lp++, ep[-1]==(CCL|STAR)));
+		ep =+ *ep;
+		goto star;
+
+	star:
+		do {
+			lp--;
+			if (advance(lp, ep))
+				return(1);
+		} while (lp > curlp);
+		return(0);
+
+	default:
+		printf2("RE botch\n");
+	}
+}
+
+cclass(aset, ac, af)
+{
+	register char *set, c;
+	register n;
+
+	set = aset;
+	if ((c = ac) == 0)
+		return(0);
+	n = *set++;
+	while (--n)
+		if (*set++ == c)
+			return(af);
+	return(!af);
+}
+
+printf2(s, a)
+{
+	extern fout;
+	flush();
+	fout = 2;
+	printf(s, a);
+	flush();
+	exit(2);
+}
+
+succeed(f)
+{
+	if (cflag) {
+		if (++tln[1]==0)
+			tln[0]++;
+		return;
+	}
+	if (nfile > 1)
+		printf("%s:", f);
+	if (bflag)
+		printf("%l:", blkno);
+	if (nflag)
+		printf("%s:", locv(lnum[0], lnum[1]));
+	printf("%s\n", linebuf);
+}