네트워크 프로그래밍 중 파일 디스크립터 관련 질문입니다.

#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
 
#define MAX_BUF 1024
 
//TCP/IP Server
int main(int argc, char *argv[]) {
	int serv_sock, clnt_sock, pid, i;
	int arr[10] = {0,};
	int clnt_count = 0;
	char message[MAX_BUF];
	struct sockaddr_in serv_addr;
	struct sockaddr_in clnt_addr;
	socklen_t clnt_addr_size;
 
	if(argc != 2) {
		printf("input : %s <prot number>\n",argv[0]);
 
		serv_sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
		if(serv_sock == -1) printf("socket() error\n");
 
		memset(&serv_addr, 0, sizeof(serv_addr));
		serv_addr.sin_family = AF_INET;
		serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
		serv_addr.sin_port = htons(atoi(argv[1]));
 
		if(bind(serv_sock, (struct sockaddr*) &serv_addr, sizeof(serv_addr))== -1)
			printf("bind() error\n");
 
		if(listen(serv_sock, 5) == -1 )
			printf("listen() error\n");
 
		clnt_addr_size = sizeof(clnt_addr);
		printf("%d\n",serv_sock);
 
		while(1) {
			clnt_sock = accept(serv_sock, (struct sockaddr*) &clnt_addr, &clnt_addr_size);
			if(clnt_sock == -1) {
				continue;
			} else {
				arr[clnt_count] = clnt_sock;
				clnt_count+=1;
			}
 
			memset(message, 0, sizeof(message));
 
			pid = fork();
			get_pid = getpid();
			if(pid < 0) {
				printf("fork Error\n");
			} else if(pid == 0) { //자식
				printf("fd : %d, pid : %d\n",clnt_sock,get_pid);
				close(serv_sock);
				while(1) {
					if(read(clnt_sock, message, sizeof(message))==-1) continue;
					if(strcmp(message,"q\n") == 0) {
						printf("%d(%d) END\n",get_pid, clnt_sock);
						close(clnt_sock);
						exit(0);
					} else {
						for(i=0; i<clnt_count; i++) {
							if(arr[i] != 0)
								write(arr[i], message, sizeof(message));
				  }
						memset(message, 0, sizeof(message));
					}
				}
			} else { //부모
			}
		}
		close(serv_sock);
		return 0;
	}