client.c

Linux网络编程教程适合初学者入门学习

#include <stdio.h>
#include <errno.h>
#include <netinet/in.h>
#include <signal.h>
#include <ctype.h>
#include <fcntl.h>

#define MAX_LINE   500
#define MAX_NAME   100

int init_cli();

#ifndef __SELECT__
int     main( void)
{
	int		sockfd;
	int		status;
	char	str[MAX_LINE];
    char    name[MAX_NAME];

	sockfd = init_cli();
	if ( sockfd == 0) {
		printf( "Init client socket error.\n");
		fflush( stdout);
		exit( 1);
	}
    fcntl( sockfd, F_SETFL, O_NONBLOCK);

    fprintf( stdout, "Please input your name:");
    fscanf( stdin, "%s", name);
    strcpy( str, "/");
    strcat( str, name);
    write( sockfd, str, strlen( str));
    fcntl( 0, F_SETFL, O_NONBLOCK);

    while ( 1) {
        if ( (status = read( sockfd, str, MAX_LINE))>=0 ) {
            if ( status == 0) exit(0); 
            str[status] = '\0';
            printf( "%s", str);
            fflush( stdout);
        }
        if ( (status = read( 0, str, MAX_LINE))>0) { 
            str[status] = '\0';
            if ( str[0] == 'q') {
                sprintf( str, "%s leave the room.\n", name);
                write( sockfd, str, strlen( str));
                close( sockfd);
                exit( 0);
            }
            write( sockfd, str, strlen(str));
        } 
   }
   return 1;
}
#endif // __SELECT__

int	init_cli( void) 
// Return sockfd if successful, else 0
{

	int 	sockfd;
	int		SERV_TCP_PORT;
	char	SERV_HOST_ADDR[MAX_LINE];
	FILE    *fd;
	struct	sockaddr_in	serv_addr;

	fd = fopen( "config", "r");
	fgets( SERV_HOST_ADDR, MAX_LINE, fd);
	fscanf( fd, "%d", &SERV_TCP_PORT);
	fclose( fd);

	bzero( (char*)&serv_addr, sizeof( serv_addr));
	serv_addr.sin_family 	  =AF_INET;
	serv_addr.sin_addr.s_addr =inet_addr( SERV_HOST_ADDR);
	serv_addr.sin_port	  =htons( SERV_TCP_PORT);

	if ( ( sockfd = socket( AF_INET,SOCK_STREAM,0))<0) {
		printf( "client:can`t open stream socker.\n");
		fflush( stdout);
		return( 0);
	}
	
	if ( connect( sockfd, ( struct sockaddr *)&serv_addr, 
		sizeof( serv_addr))<0) {
		printf( "client:can`t connect to server\n");
		fflush( stdout);
		return( 0);
	}
	return( sockfd);
}