Socket Programming Error In C - c

Question

i have an infinite loop problem while im trying to send some messages from client to the server. Client has some commands like login, getusers, alias etc. and i want to check them into server. Here its my code.
CLIENT
#include<stdio.h>
#include<sys/socket.h>
#include<arpa/inet.h> // for inet_addr
#include <string.h>
#include <zconf.h>
int main(int argc, char *argv[]) {
int sock;
struct sockaddr_in server;
char message[2000], server_reply[2000];
//Create socket
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == -1) {
printf("Could not create socket");
}
server.sin_addr.s_addr = inet_addr("127.0.0.1");
server.sin_family = AF_INET;
server.sin_port = htons(8888);
//Connect to remote server
if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0) {
perror("Connect failed. Error");
return 1;
}
puts("Connected to server\n");
//keep communicating with server
while (1) {
printf("> ");
scanf("%[^\n]s", message);
fflush(stdin);
//Send some data
if (send(sock, message, strlen(message), 0) < 0) {
puts("Send failed");
return 1;
}
//Receive a reply from the server
if (recv(sock, server_reply, 2000, 0) < 0) {
puts("recv failed");
break;
}
printf("Server's reply : %s ", server_reply);
}
close(sock);
return 0;
}
SERVER
#include<stdio.h>
#include<string.h> // for strlen
#include<stdlib.h>
#include<sys/socket.h>
#include<arpa/inet.h> // for inet_addr
#include<unistd.h> // for write
#include<pthread.h> // for threading, link with lpthread
#include "server.h"
#include "split.h"
#define MAX_CLIENT_NUMBER 100
void *connection_handler(void *);
struct User {
char userName[10];
int clientSocketNo;
};
struct User users[MAX_CLIENT_NUMBER];
void getUsers() {
printf("Number %d",userArrayIndex);
for (int i = 0; i < userArrayIndex; ++i) {
printf("%s\n", users[i].userName);
}
}
void addUserToArray(char userName[10], int socketNumber) {
printf("Client logged in as %s\n", userName);
strcpy(users[userArrayIndex].userName, userName);
users[userArrayIndex].clientSocketNo = socketNumber;
userArrayIndex++;
}
void loginUser(char userName[10], int socketNumber) {
char *message = "login successful";
write(socketNumber, message, strlen(message));
addUserToArray(userName, socketNumber);
}
void *connection_handler(void *socket_desc) {
//Get the socket descriptor
char receivedMessage[2000]; //client's message
int readControl;
int sock = *((int *) socket_desc);
while ((readControl = recv(sock, receivedMessage, 2000, 0)) > 0) {
char **parsedCommand = malloc(100); //parsedClientMessage
parsing(parsedCommand, receivedMessage, " ");
printf("MESSAGE %s\n",parsedCommand[0]);
if (strcmp(parsedCommand[0], "login") == 0) {
loginUser(parsedCommand[1], sock);
}
if (strcmp(parsedCommand[0], "getusers") == 0) {
getUsers();
}
if (strcmp(parsedCommand[0], "exit") == 0) {
close(sock);
return 0;
}
}
if (readControl == 0) {
puts("Client disconnected");
clientNumber--;
fflush(stdout);
} else if (readControl == -1) {
perror("recv failed");
}
//Free the socket pointer
free(socket_desc);
return 0;
}
int main(int argc, char *argv[]) {
int socket_desc, new_socket, c, *new_sock;
struct sockaddr_in server, client;
//Create Socket
socket_desc = socket(AF_INET, SOCK_STREAM, 0);
if (socket_desc == -1) {
puts("Could not create socket");
return 1;
}
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons(8888);
if (bind(socket_desc, (struct sockaddr *) &server, sizeof(server)) < 0) {
puts("Binding failed");
return 1;
}
listen(socket_desc, 3);
puts("Server started");
c = sizeof(struct sockaddr_in);
while ((new_socket = accept(socket_desc, (struct sockaddr *) &client, (socklen_t *) &c)) &&
clientNumber < MAX_CLIENT_NUMBER) {
pthread_t sniffer_thread/*[MAX_CLIENT_NUMBER]*/;
new_sock = malloc(1);
*new_sock = new_socket;
if (pthread_create(&sniffer_thread/*[clientNumber]*/, NULL, connection_handler,
(void *) new_sock) < 0) {
perror("Could not create thread");
return 1;
} else {
clientNumber++;
}
puts("Client connected");
}
if (new_socket < 0) {
perror("accept failed");
return 1;
}
return 0;
}
Its not full of my code but i think our problem in these parts. I dont understand why it happens. When i insert a break command into connection_handler's while loop, i cant send commands to the server anymore. Thanks...

Answer 1

I solved it. when i malloc the messages or replies, i give +1 to strlen(messsage).
So its strlen(message)+1 solved my problem

Answer 2

Because the '\n' is not removed from the input, the scanf() function is able to reuse that last character for a next entry.
The easiest solution to solve that problem is to clear the input
buffer fflush(stdin);.
while (1) {
printf("> ");
scanf("%[^\n]s", message);
fflush(stdin); // to clear \n from the buffer
//Send some data
if (send(sock, message, strlen(message), 0) < 0) {