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#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#if EMSCRIPTEN
#include <emscripten.h>
#endif
int serverfd = 0;
int clientfd = 0;
void cleanup() {
if (serverfd) close(serverfd);
if (clientfd) close(clientfd);
}
void do_send(int sockfd) {
static char* buffers[] = {
"\x09\x01\x02\x03\x04\x05\x06\x07\x08\x09\0",
"\x08\x01\x02\x03\x04\x05\x06\x07\x08\0",
"\x07\x01\x02\x03\x04\x05\x06\x07\0",
"\x06\x01\x02\x03\x04\x05\x06\0",
"\x05\x01\x02\x03\x04\x05\0",
"\x04\x01\x02\x03\x04\0",
"\x03\x01\x02\x03\0",
"\x02\x01\x02\0",
"\x01\x01\0"
};
int i;
int res;
char *buffer;
struct sockaddr_in addr;
socklen_t addrlen;
for (i = 0; i < sizeof(buffers) / sizeof(char*); i++) {
buffer = buffers[i];
res = sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&addr, sizeof(addr));
if (res == -1) {
perror("send failed");
exit(EXIT_FAILURE);
}
printf("sent \"%s\" (%d bytes)\n", buffer, res);
}
exit(EXIT_SUCCESS);
}
void iter(void *arg) {
int res;
fd_set fdr;
fd_set fdw;
// see if there are any connections to accept / write to
FD_ZERO(&fdr);
FD_ZERO(&fdw);
FD_SET(serverfd, &fdr);
if (clientfd) FD_SET(clientfd, &fdw);
res = select(64, &fdr, &fdw, NULL, NULL);
if (res == -1) {
perror("select failed");
exit(EXIT_SUCCESS);
}
if (FD_ISSET(serverfd, &fdr)) {
printf("accepted someone\n");
clientfd = accept(serverfd, NULL, NULL);
assert(clientfd != -1);
}
if (FD_ISSET(clientfd, &fdw)) {
do_send(clientfd);
}
}
int main() {
struct sockaddr_in addr;
int res;
atexit(cleanup);
signal(SIGTERM, cleanup);
// create the socket
serverfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (serverfd == -1) {
perror("cannot create socket");
exit(EXIT_FAILURE);
}
fcntl(serverfd, F_SETFL, O_NONBLOCK);
// bind and listen to the supplied port
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(SOCKK);
if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
perror("inet_pton failed");
exit(EXIT_FAILURE);
}
res = bind(serverfd, (struct sockaddr *)&addr, sizeof(addr));
if (res == -1) {
perror("bind failed");
exit(EXIT_FAILURE);
}
res = listen(serverfd, 50);
if (res == -1) {
perror("listen failed");
exit(EXIT_FAILURE);
}
#if EMSCRIPTEN
emscripten_set_main_loop(iter, 60, 0);
#else
while (1) iter(NULL);
#endif
return EXIT_SUCCESS;
}
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