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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
enum {
COORPERATION = 'c',
DEFECTION = 'd'
};
int pay(int a, int b)
{
assert(a == COORPERATION || a == DEFECTION);
assert(b == COORPERATION || b == DEFECTION);
if (a == COORPERATION && b == DEFECTION) return 1;
if (a == DEFECTION && b == DEFECTION) return 2;
if (a == COORPERATION && b == COORPERATION) return 3;
if (a == DEFECTION && b == COORPERATION) return 4;
exit(EXIT_FAILURE);
}
int
main(int argc, char *argv[])
{
int sock, player[2];
struct sockaddr_in serv_addr;
int port = 8068;
int a_payment = 0, b_payment = 0, rounds, i;
int optval = 1;
char *endptr;
errno = 0;
if (argc < 2 || (rounds = strtol(argv[1], NULL, 10)) <= 0 || errno!=0) {
fprintf(stderr, "usage: %s number-of-rounds\n", argv[0]);
exit(EXIT_FAILURE);
}
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0)
return EXIT_FAILURE;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
&optval, sizeof optval);
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(port);
if (bind(sock, (struct sockaddr *) &serv_addr,
sizeof(serv_addr)) < 0) {
fprintf(stderr, "Failed to bind: %s\n",
strerror(errno));
return EXIT_FAILURE;
}
listen(sock, 2);
for (;;) {
a_payment = 0;
b_payment = 0;
for (i = 0; i < 2; ++i) {
player[i] = accept(sock, NULL, NULL);
}
for (i = 0; i < rounds; ++i) {
char a, b;
read(player[0], &a, 1);
read(player[1], &b, 1);
if (a != 'c' && a != 'd') {
printf("a sent incorrect char: %c\n", a);
continue;
}
if (b != 'c' && b != 'd') {
printf("b sent incorrect char: %c\n", b);
continue;
}
a_payment += pay(a, b);
b_payment += pay(b, a);
printf("A [%c]: %d Euro\tB [%c]: %d Euro\t\t\t"
"A: %d\tB: %d\n",
a, pay(a,b), b, pay(b,a), a_payment, b_payment);
write(player[0], &b, 1);
write(player[1], &a, 1);
}
close(player[0]);
close(player[1]);
}
close(sock);
}
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