tcp_serv.c

Unix/Linux下服务端/客户通过TCP/IP通讯的程序

#include "tcp.h"

int my_sock;

main(argc, argv)
int argc;
char * argv[];
{
	int sockfd,newsockfd ;
	int clilen, childpid;
	char s[512];
	struct sockaddr_in serv_addr, cli_addr;
	extern void sig_finish();

	signal ( SIGINT, sig_finish );
	/**** 	Internet Address Family: AF_INET 
		scoket type : SOCK_STREAME 		***/
	if( (sockfd = socket( AF_INET, SOCK_STREAM,0)) < 0 ) 
		err_sys( "Server: can't open socket " ) ;
	my_sock = sockfd;
	printf( "TCP SOCKET IS SUCCESS LOAD IN! Sockfd = %d\n", sockfd );

	bzero( (char *)&serv_addr, sizeof(serv_addr ) );
	serv_addr.sin_family = AF_INET;	
	serv_addr.sin_addr.s_addr = htonl( INADDR_ANY );	
	serv_addr.sin_port = htons( TCP_PORT );	
	if ( bind( sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr))<0)
		err_sys( "Server: can't bind local address " ) ;
	printf( "TCP BIND IS SUCCESS LOAD IN! The Internet Address is %d\n",htonl(INADDR_ANY) );
	
	listen( sockfd, 5 );
	printf( "TCP LISTEN IS SUCCESS LOAD IN!\n" );

	while(1) {
		clilen = sizeof( cli_addr );	
		newsockfd=accept(sockfd, (struct sockaddr *)&cli_addr,&clilen );
		printf( "Accept a requess! newsocket is %d\n", newsockfd );
		if ( newsockfd < 0 ) 
			err_sys( "Server: sccept error " );

		if ( ( childpid = fork() ) < 0 ) 
			err_sys( "Server: fork error " );
		else if ( childpid == 0 ) {
			close( sockfd );
			serv_con( newsockfd );
			exit(0);
		}
		close( newsockfd );
	}
	close( sockfd );

}
serv_con( fd )
int fd; 
{
	int n;
	char line[MAXLINE];
	while(1) {
		n = readline( fd, line, MAXLINE );		
		if ( n==0 ) return (0);
		else if( n<0 ) err_sys( "serv_con: readline error!" );
		printf( "line is %s", line );
/*
		if ( write( 1, line, n ) != n ) 
			err_sys( "serv_con:write stdsrc error !" );
		if ( writen( fd, line, n )!=0 ) 
			err_sys( "serv_con:write to newsockfd error! " );
*/
	}
}
err_sys(s)
char *s;
{
	printf( s );
	exit(0);
}
void sig_finish ()
{
	printf( "this is end!\n" );
	close( my_sock );	
	exit(0);
}