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| #include <arpa/inet.h> #include <assert.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <errno.h> #include <string.h>
int main(int argc, char* argv[]) { if (argc <= 2) { printf("usage: %s ip_address port_number\n", basename(argv[0])); return 1; } const char* ip = argv[1]; int port = atoi(argv[2]);
struct sockaddr_in address = {0}; address.sin_family = AF_INET; inet_pton(AF_INET, ip, &address.sin_addr); address.sin_port = htons(port); int sock = socket(PF_INET, SOCK_STREAM, 0); assert(sock >= 0);
int ret = bind(sock, (struct sockaddr*)&address, sizeof(address)); assert(ret != -1);
ret = listen(sock, 5); assert(ret != -1);
struct sockaddr_in client; socklen_t client_addrlength = sizeof(client); int connfd = accept(sock, (struct sockaddr*)&client, &client_addrlength); if (connfd < 0) { printf("errno is: %d\n", errno); } else { char remote[INET_ADDRSTRLEN]; printf("connected with ip: %s and port: %d\n", inet_ntop(AF_INET, &client.sin_addr, remote, INET_ADDRSTRLEN), ntohs(client.sin_port)); close(connfd); }
close(sock); return 0; }
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