Add original unix v6

source/s1/cron.c

@@ -0,0 +1,234 @@
+#define	ANY	-1
+#define	LIST	-2
+#define	RANGE	-3
+#define	EOF	-4
+char	*crontab	"/usr/lib/crontab";
+char	*crontmp	"/tmp/crontmp";
+char	*aend;
+char	*itime[2];
+int	*loct;
+int	*localtime();
+int	reset();
+int	flag;
+
+main()
+{
+	register i, t;
+	register char *cp;
+	extern char end[];
+
+	setuid(1);
+	itime[0] = fork();
+	if(itime[0])
+		exit();
+	setexit();
+	signal(1, reset);
+	time(itime);
+	while(*localtime(itime))
+		if(itime[1]-- == 0)
+			itime[0]--;
+
+loop:
+	init();
+	for(i=60; i; i--) {
+		loct = localtime(itime);
+		for(cp = end; *cp != EOF;) {
+			flag = 0;
+			cp = cmp(cp, loct[1]); /* minute */
+			cp = cmp(cp, loct[2]); /* hour */
+			cp = cmp(cp, loct[3]); /* day */
+			cp = cmp(cp, loct[4]); /* month */
+			cp = cmp(cp, loct[6]); /* day of week */
+			if(flag == 0) {
+				slp();
+				ex(cp);
+			}
+			while(*cp++ != 0)
+				;
+		}
+		t = itime[1] + 60;
+		if(t < itime[1])
+			itime[0]++;
+		itime[1] = t;
+	}
+	slp();
+	goto loop;
+}
+
+cmp(p, v)
+char *p;
+{
+	register char *cp;
+
+	cp = p;
+	switch(*cp++) {
+
+	case ANY:
+		return(cp);
+
+	case LIST:
+		while(*cp != LIST)
+			if(*cp++ == v) {
+				while(*cp++ != LIST)
+					;
+				return(cp);
+			}
+		flag++;
+		return(cp+1);
+
+	case RANGE:
+		if(*cp > v || cp[1] < v)
+			flag++;
+		return(cp+2);
+	}
+	if(cp[-1] != v)
+		flag++;
+	return(cp);
+}
+
+slp()
+{
+	register i;
+	int	t[2];
+
+	time(t);
+	i = itime[1] - t[1];
+	if(i > 0)
+		sleep(i);
+}
+
+ex(s)
+char *s;
+{
+	register i;
+
+	if(fork()) {
+		wait();
+		return;
+	}
+	for(i=0; s[i]; i++);
+	close(0);
+	creat(crontmp, 0600);
+	write(0, s, i);
+	close(0);
+	open(crontmp, 0);
+	unlink(crontmp);
+	if(fork())
+		exit();
+	execl("/bin/sh", "sh", "-t", 0);
+	exit();
+}
+
+init()
+{
+	int ib[259], t[10];
+	register i, c;
+	register char *cp;
+	char *ocp;
+	int n;
+	extern char end[];
+
+	if(fopen(crontab, ib) < 0) {
+		write(1, "cannot open table\n", 18);
+		exit();
+	}
+	cp = end;
+	if(aend == 0)
+		aend = cp;
+
+loop:
+	ocp = cp;
+	if(cp+100 > aend) {
+		aend =+ 512;
+		brk(aend);
+	}
+	for(i=0;; i++) {
+		do
+			c = getc(ib);
+		while(c == ' ' || c == '\t');
+		if(c <= 0 || c == '\n')
+			goto ignore;
+		if(i == 5)
+			break;
+		if(c == '*') {
+			*cp++ = ANY;
+			continue;
+		}
+		n = 0;
+		while(c >= '0' && c <= '9') {
+			n = n*10 + c-'0';
+			c = getc(ib);
+		}
+		if(n < 0 || n > 100)
+			goto ignore;
+		if(c == ',')
+			goto list;
+		if(c == '-')
+			goto range;
+		if(c != '\t' && c != ' ')
+			goto ignore;
+		*cp++ = n;
+		continue;
+
+	list:
+		*cp++ = LIST;
+		*cp++ = n;
+	list1:
+		n = 0;
+		c = getc(ib);
+		while(c >= '0' && c <= '9') {
+			n = n*10 + c-'0';
+			c = getc(ib);
+		}
+		if(n < 0 || n > 100)
+			goto ignore;
+		*cp++ = n;
+		if(c == ',')
+			goto list1;
+		if(c != '\t' && c != ' ')
+			goto ignore;
+		*cp++ = LIST;
+		continue;
+
+	range:
+		*cp++ = RANGE;
+		*cp++ = n;
+		n = 0;
+		c = getc(ib);
+		while(c >= '0' && c <= '9') {
+			n = n*10 + c-'0';
+			c = getc(ib);
+		}
+		if(n < 0 || n > 100)
+			goto ignore;
+		if(c != '\t' && c != ' ')
+			goto ignore;
+		*cp++ = n;
+	}
+	while(c != '\n') {
+		if(c <= 0)
+			goto ignore;
+		if(c == '%')
+			c = '\n';
+		*cp++ = c;
+		c = getc(ib);
+	}
+	*cp++ = '\n';
+	*cp++ = 0;
+	goto loop;
+
+ignore:
+	cp = ocp;
+	while(c != '\n') {
+		if(c <= 0) {
+			close(ib[0]);
+			*cp++ = EOF;
+			*cp++ = EOF;
+			aend = cp;
+			brk(aend);
+			return;
+		}
+		c = getc(ib);
+	}
+	goto loop;
+}