Files
tcp-ip-sockets-in-c/ch1/TCPEchoClient4.c
2026-09-06 17:43:06 +03:00

71 lines
2.1 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "Practical.h"
int main(int argc, char **argv) {
if (argc < 3 || argc > 4) {
DieWithUserMessage("Parameter(s)", "<Server Address> <Echo Word> [<Server Port>]");
}
const char *server_ip = argv[1];
const char *echo_str = argv[2];
const in_port_t server_port = (argc == 4) ? atoi(argv[3]) : 7; // 7: common echo port
const int sock = socket(AF_INET, SOCK_STREAM, proto_get_num("tcp"));
if (sock < 0) {
DieWithSystemMessage("socket() failed");
}
struct sockaddr_in server_addr = {0};
server_addr.sin_family = AF_INET;
int ret_val = inet_pton(AF_INET, server_ip, &server_addr.sin_addr.s_addr);
if (ret_val == 0) {
DieWithUserMessage("inet_pton() failed", "invalid address string");
} else if (ret_val < 0) {
DieWithSystemMessage("inet_pton() failed");
}
server_addr.sin_port = htons(server_port);
if (connect(sock, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0) {
DieWithSystemMessage("connect() failed");
}
const size_t echo_str_len = strlen(echo_str);
ssize_t num_bytes = send(sock, echo_str, echo_str_len, 0);
if (num_bytes < 0) {
DieWithSystemMessage("send() failed");
} else if ((size_t) num_bytes != echo_str_len) {
DieWithUserMessage("send()", "sent unexpected number of bytes");
}
unsigned int total_bytes_rcvd = 0;
fputs("Received: ", stdout);
while (total_bytes_rcvd < echo_str_len) {
char buffer[BUFSIZE];
num_bytes = recv(sock, buffer, BUFSIZE - 1, 0);
if (num_bytes < 0) {
DieWithSystemMessage("recv() failed");
} else if (num_bytes == 0) {
DieWithUserMessage("recv()", "connection closed prematurely");
}
total_bytes_rcvd += num_bytes;
buffer[num_bytes] = '\0';
fputs(buffer, stdout);
}
fputc('\n', stdout);
close(sock);
return 0;
}