#include <sys/socket.h>
#include <sys/types.h>
#include <signal.h>
#include <string.h>
#include <netinet/in.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <arpa/inet.h>#define PORT_NUM     5555
#define    MAX_CLIENT    100typedef struct {int    index;int    using;        //using or not
            pthread_t tid;int client_com_fd;struct sockaddr_in client_addr;int     client_addr_len;
}mythread_arg_t;mythread_arg_t    pthread_arg_array[MAX_CLIENT];print_thread(int index)
{int    i = index;printf("=======================thread data=======================\n");printf("pthread_arg_array[i].index = %d\n", pthread_arg_array[i].index);printf("pthread_arg_array[i].using = %d\n", pthread_arg_array[i].using);printf("pthread_arg_array[i].tid = 0x%lx\n", pthread_arg_array[i].tid);printf("pthread_arg_array[i].client_com_fd = %d\n", pthread_arg_array[i].client_com_fd);printf("pthread_arg_array[i].client_addr = %s\n", inet_ntoa(pthread_arg_array[i].client_addr.sin_addr));printf("=======================thread end========================\n");
}void *do_client( void *arg)
{char buf[1400];int i = (int)(long)arg;while(1) {int ret = recv(pthread_arg_array[i].client_com_fd, buf, sizeof(buf), 0);if(ret == -1 || ret == 0) {perror("recv");break;}if(!strncmp(buf, "exit", 4)){break;}printf("recv from client address: %s data: %s\n", inet_ntoa(pthread_arg_array[i].client_addr.sin_addr), buf);}print_thread(i);close(pthread_arg_array[i].client_com_fd);pthread_arg_array[i].using = 0;
}void client_exit(int signo)
{pid_t pid;pid = wait( NULL );            //close( listen_fd );printf("pid = %d exit.\n", pid );
}int main( int argc, char ** argv )
{int listen_fd = socket( AF_INET, SOCK_STREAM, 0 );    struct sockaddr_in myaddr;myaddr.sin_family = AF_INET;myaddr.sin_port = htons(PORT_NUM);myaddr.sin_addr.s_addr = htonl(INADDR_ANY);int ret;int    i;signal(SIGCHLD, client_exit);ret = bind(listen_fd, (struct sockaddr *)&myaddr, sizeof(struct sockaddr));if(-1 == ret) {perror("bind");exit(1);}listen(listen_fd, 20);struct sockaddr_in client_addr;int client_addr_len = sizeof(struct sockaddr);int client_com_fd;while(1) {//find an no using entryfor(i = 0; (i < MAX_CLIENT)&&(1 == pthread_arg_array[i].using); i++);if(i >= MAX_CLIENT){printf("overload!\n");close(client_com_fd);continue;}printf("i = %d\n", i );client_com_fd = accept(listen_fd,(struct sockaddr *)&client_addr, &client_addr_len);pthread_arg_array[i].using = 1;printf("ip address %s have send connect request.\n", inet_ntoa(client_addr.sin_addr));pthread_arg_array[i].index = i;pthread_arg_array[i].client_com_fd = client_com_fd;pthread_arg_array[i].client_addr = client_addr;pthread_arg_array[i].client_addr_len = client_addr_len;pthread_t *ptid = &(pthread_arg_array[i].tid);if(-1 == pthread_create(ptid, NULL, do_client, (void *)(long)i)){printf("pthread_creat()\n");continue;}/*pid_t pid;pid = fork();if( pid < 0 ) {perror("fork");exit( 3 );} else if( pid == 0 ) {close( listen_fd );            do_client( client_com_fd, client_addr );close( client_com_fd );exit( 0 );}
*/}//close( client_com_fd );//close( listen_fd );
}

#include <sys/socket.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <stdio.h>#define PORT_NUM     5555
#define LENGTH  1460int main(int argc, char *argv[])
{if(2 != argc) {exit(1);}int sock_fd = socket(AF_INET, SOCK_STREAM, 0);struct sockaddr_in server_addr;server_addr.sin_family = AF_INET;server_addr.sin_port = htons(PORT_NUM);server_addr.sin_addr.s_addr = inet_addr(argv[1]);int ret = connect(sock_fd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));if(-1 == ret) {perror("connect");exit(2);}char buf[LENGTH];while(1) {printf("Input str: ");//gets(buf);
        fgets(buf, LENGTH, stdin);send(sock_fd, buf, strlen(buf)+1, 0);if(!strncmp(buf, "exit", 4)) {break;}}close(sock_fd);
}