add new guys
diff --git a/src/cmd/primes.c b/src/cmd/primes.c
new file mode 100644
index 0000000..0e92654
--- /dev/null
+++ b/src/cmd/primes.c
@@ -0,0 +1,131 @@
+#include <u.h>
+#include <libc.h>
+
+#define ptsiz (sizeof(pt)/sizeof(pt[0]))
+#define whsiz (sizeof(wheel)/sizeof(wheel[0]))
+#define tabsiz (sizeof(table)/sizeof(table[0]))
+#define tsiz8 (tabsiz*8)
+
+double big = 9.007199254740992e15;
+
+int pt[] =
+{
+ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29,
+ 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,
+ 73, 79, 83, 89, 97,101,103,107,109,113,
+ 127,131,137,139,149,151,157,163,167,173,
+ 179,181,191,193,197,199,211,223,227,229,
+};
+double wheel[] =
+{
+ 10, 2, 4, 2, 4, 6, 2, 6, 4, 2,
+ 4, 6, 6, 2, 6, 4, 2, 6, 4, 6,
+ 8, 4, 2, 4, 2, 4, 8, 6, 4, 6,
+ 2, 4, 6, 2, 6, 6, 4, 2, 4, 6,
+ 2, 6, 4, 2, 4, 2,10, 2,
+};
+uchar table[1000];
+uchar bittab[] =
+{
+ 1, 2, 4, 8, 16, 32, 64, 128,
+};
+
+void mark(double nn, long k);
+void ouch(void);
+
+void
+main(int argc, char *argp[])
+{
+ int i;
+ double k, temp, v, limit, nn;
+
+ if(argc <= 1) {
+ fprint(2, "usage: primes starting [ending]\n");
+ exits("usage");
+ }
+ nn = atof(argp[1]);
+ limit = big;
+ if(argc > 2) {
+ limit = atof(argp[2]);
+ if(limit < nn)
+ exits(0);
+ if(limit > big)
+ ouch();
+ }
+ if(nn < 0 || nn > big)
+ ouch();
+ if(nn == 0)
+ nn = 1;
+
+ if(nn < 230) {
+ for(i=0; i<ptsiz; i++) {
+ if(pt[i] < nn)
+ continue;
+ if(pt[i] > limit)
+ exits(0);
+ print("%d\n", pt[i]);
+ if(limit >= big)
+ exits(0);
+ }
+ nn = 230;
+ }
+
+ modf(nn/2, &temp);
+ nn = 2.*temp + 1;
+/*
+ * clear the sieve table.
+ */
+ for(;;) {
+ for(i=0; i<tabsiz; i++)
+ table[i] = 0;
+/*
+ * run the sieve.
+ */
+ v = sqrt(nn+tsiz8);
+ mark(nn, 3);
+ mark(nn, 5);
+ mark(nn, 7);
+ for(i=0,k=11; k<=v; k+=wheel[i]) {
+ mark(nn, k);
+ i++;
+ if(i >= whsiz)
+ i = 0;
+ }
+/*
+ * now get the primes from the table
+ * and print them.
+ */
+ for(i=0; i<tsiz8; i+=2) {
+ if(table[i>>3] & bittab[i&07])
+ continue;
+ temp = nn + i;
+ if(temp > limit)
+ exits(0);
+ print("%.0f\n", temp);
+ if(limit >= big)
+ exits(0);
+ }
+ nn += tsiz8;
+ }
+}
+
+void
+mark(double nn, long k)
+{
+ double t1;
+ long j;
+
+ modf(nn/k, &t1);
+ j = k*t1 - nn;
+ if(j < 0)
+ j += k;
+ for(; j<tsiz8; j+=k)
+ table[j>>3] |= bittab[j&07];
+}
+
+void
+ouch(void)
+{
+ fprint(2, "limits exceeded\n");
+ exits("limits");
+}
