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#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <assert.h>
#if EMSCRIPTEN
#include <emscripten.h>
#endif
int sockfd = -1;
int sum = 0;
void finish(int result) {
close(sockfd);
#if EMSCRIPTEN
REPORT_RESULT();
#endif
exit(result);
}
void iter(void *arg) {
char buffer[1024];
char packetLength;
fd_set fdr;
int i;
int res;
// make sure that sockfd is ready to read
FD_ZERO(&fdr);
FD_SET(sockfd, &fdr);
res = select(64, &fdr, NULL, NULL, NULL);
if (res == -1) {
perror("select failed");
finish(EXIT_FAILURE);
} else if (!FD_ISSET(sockfd, &fdr)) {
return;
}
res = recv(sockfd, buffer, 1, 0);
if (res == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
return; //try again
}
perror("unexcepted end of data");
finish(EXIT_FAILURE);
}
if (res != 1) {
perror("should read 1 byte");
finish(EXIT_FAILURE);
}
packetLength = buffer[0];
res = recv(sockfd, buffer, packetLength, 0);
printf("got %d,%d\n", res, packetLength);
if (res != packetLength) {
fprintf(stderr, "lost packet data, expected: %d readed: %d", packetLength, res);
finish(EXIT_FAILURE);
}
for (i = 0; i < packetLength; ++i) {
if (buffer[i] != i+1) {
fprintf(stderr, "packet corrupted, expected: %d, actual: %d", i+1, buffer[i]);
finish(EXIT_FAILURE);
}
sum += buffer[i];
}
if (packetLength == buffer[0]) { // \x01\x01 - end marker
printf("sum: %d\n", sum);
finish(sum);
}
}
int main() {
struct sockaddr_in addr;
int res;
sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sockfd == -1) {
perror("cannot create socket");
exit(EXIT_FAILURE);
}
fcntl(sockfd, F_SETFL, O_NONBLOCK);
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");
finish(EXIT_FAILURE);
}
res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
if (res == -1 && errno != EINPROGRESS) {
perror("connect failed");
finish(EXIT_FAILURE);
}
#if EMSCRIPTEN
emscripten_set_main_loop(iter, 0, 0);
#else
while (1) iter(NULL);
#endif
return EXIT_SUCCESS;
}
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