--- /dev/null
+#include <stdlib.h>
+#include <stdio.h>
+#include <jh.h>
+#include <unistd.h>
+#include <time.h>
+#include <assert.h>
+
+time_t real_seconds(void) {
+ struct timespec t;
+ int s = clock_gettime(CLOCK_REALTIME, &t);
+ assert(s==0);
+ return t.tv_sec;
+}
+
+/* Subtract the `struct timeval' values X and Y,
+ storing the result in RESULT.
+ Return 1 if the difference is negative, otherwise 0. */
+int timeval_subtract (struct timeval *result, struct timeval *x, struct timeval *y) {
+ /* Perform the carry for the later subtraction by updating y. */
+ if (x->tv_usec < y->tv_usec) {
+ int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
+ y->tv_usec -= 1000000 * nsec;
+ y->tv_sec += nsec;
+ }
+ if (x->tv_usec - y->tv_usec > 1000000) {
+ int nsec = (x->tv_usec - y->tv_usec) / 1000000;
+ y->tv_usec += 1000000 * nsec;
+ y->tv_sec -= nsec;
+ }
+
+ /* Compute the time remaining to wait.
+ tv_usec is certainly positive. */
+ result->tv_sec = x->tv_sec - y->tv_sec;
+ result->tv_usec = x->tv_usec - y->tv_usec;
+
+ /* Return 1 if result is negative. */
+ return x->tv_sec < y->tv_sec;
+}
+
+void sleep_until(time_t dst_sec) {
+ struct timespec dst;
+ dst.tv_sec = dst_sec;
+ dst.tv_nsec = 0;
+ while (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &dst, NULL)) /* nothing */;
+}
+
+time_t round_up(time_t t, int align) {
+ t = t - 1; /* counter bad +t for aligned things in last step */
+ t = t - t%align; /* round down to align */
+ t = t + align; /* add alignment to make it a round up */
+ return t;
+}
+
+void handle_connection(int s) {
+ dup2(s, 1);
+ dup2(s, 0);
+
+ char line_in[100];
+ if (!fgets(line_in, 100, stdin)) return;
+ char *p = line_in + strlen("GET /");
+
+ setbuf(stdout, NULL);
+ printf("HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\n\r\n<!--");
+
+ char *spaaaace = malloc(1024*64);
+ memset(spaaaace, ' ', 1024*64);
+ spaaaace[0] = 'A';
+
+ time_t t = round_up(real_seconds(), 4);
+ while (1) {
+ if (*p != '0' && *p != '1') return;
+ if (*p == '1') t+=2;
+ sleep_until(t);
+ if (fwrite(spaaaace, 1024, 64, stdout) <= 0) return;
+ t += (*p == '1') ? 2 : 4;
+ p++;
+ }
+}
+
+int main(void) {
+ int s = netopen_server(NULL, "4422", JH_TCP_HINTS);
+ while (1) {
+ int s_ = accept(s, NULL, NULL);
+ pid_t p = fork();
+ if (p == 0) {
+ handle_connection(s_);
+ return 0;
+ }
+ close(s_);
+ }
+}