TCP 소켓 통신 문제

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
 
int main() {
	int serd, clid;
	char buffer[BUFSIZ];
	struct sockaddr_in socketaddr;
	struct sockaddr socbuf;
	socklen_t soclen = sizeof(struct sockaddr_in);
	ssize_t sockrwlen;
 
	memset((char*)&socketaddr, 0, sizeof(struct sockaddr_in));
	memset(&socketaddr.sin_zero, 0, 8);
	socketaddr.sin_family = AF_INET;
	socketaddr.sin_port = htons(19780);
	socketaddr.sin_addr.s_addr = inet_addr("192.168.219.102");
	serd = socket(AF_INET, SOCK_STREAM, 0);
	if (serd < 0) {
		perror("socket");
		return -1;
	}
	bind(serd, (struct sockaddr *)&socketaddr, sizeof(struct sockaddr));
 
	listen(serd, 1);
	clid = accept(serd, &socbuf, &soclen);
	if (clid < 0) {
		perror("accept");
		return -1;
	}
	printf("Connected.\n");
 
	while ((sockrwlen = recv(clid, buffer, BUFSIZ, 0)) >= 0) {
		printf("Received : '%s'\nSize : %ld\n", buffer, sockrwlen);
		sockrwlen = send(clid, buffer, sockrwlen, 0);
		printf("Sent. Size : %ld\n", sockrwlen);
		if (strcmp(buffer, "/q") == 0) break;
	}
	close(clid);
	close(serd);
	printf("Disconnected.\n");
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
 
int main() {
	int clid;
	char buffer[BUFSIZ];
	struct sockaddr_in socketaddr;
	struct sockaddr socbuf;
	ssize_t sockrwlen;
 
	memset((char*)&socketaddr, 0, sizeof(struct sockaddr_in));
	socketaddr.sin_family = AF_INET;
	socketaddr.sin_port = htons(19781);
	socketaddr.sin_addr.s_addr = inet_addr(some_thing);
	clid = socket(AF_INET, SOCK_STREAM, 0);
	if (clid < 0) {
		perror("socket");
		return -1;
	}
	printf("Connecting...\n");
	if (connect(clid, (struct sockaddr *)&socketaddr, sizeof(struct sockaddr_in))) {
		perror("connect");
		return -1;
	}
	printf("Connected.\n");
 
	while (1) {
		printf("Input a message send to server : ");
		fgets(buffer, BUFSIZ, stdin);
		buffer[strlen(buffer)-1] = '\0';
		sockrwlen = send(clid, buffer, strlen(buffer)+1, 0);
		sockrwlen = recv(clid, buffer, BUFSIZ, 0);
		printf("from server : %s\n", buffer);
		if (strcmp(buffer, "/q") == 0) break;
	}
 
	if (sockrwlen < 0) {
		perror("recv");
		return -1;
	}
 
	close(clid);
	printf("Disconnected.\n");
	return 0;
}