S8 CSE NETWORK LAB PROGRAMS

*****ECHO SERVER (CLIENT)*****

#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser;
int s,n;
char a[50],b[50],c[]="exit";
s=socket(AF_INET,SOCK_DGRAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
while(1)
{
printf("enter the message");
gets(a);
if(strcmp(a,c)==0)
break;
sendto(s,a,strlen(a)+1,0,(struct sockaddr*)&ser,sizeof(ser));
n=sizeof(ser);
recvfrom(s,b,49,0,(struct sockaddr*)&ser,&n);
printf("%s",b);
}
close(s);
}




*****ECHO SERVER (SERVER)*****

#include
#include
#include
#include
#include
#include
main()
{
int s,n;
char a[50];
struct sockaddr_in ser,cli;
s=socket(AF_INET,SOCK_DGRAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
bind(s,(struct sockaddr*)&ser,sizeof(ser));
n=sizeof(cli);
while(1)
{
recvfrom(s,a,50,0,(struct sockaddr*)&cli,&n);
sendto(s,a,strlen(a)+1,0,(struct sockaddr*)&cli,sizeof(cli));
}
close(s);
}




FILE.............................................




#include
#include
#include
#include
#include
int fp;
int status=0;
char fname[15];
struct student
{
int rno;
char name[15];
}s1,s2;

void insert();
void search();
void update();
void show();

void main()
{
int choice;
clrscr();
printf("Enter File Name:");
gets(fname);
fp=open(fname,O_CREAT | O_RDWR);
if(fp==-1)
printf("Cannot Open...\n");
else
status=1;
choice=1;
while(choice!=5)
{
close(fp);
printf("1.INSERT\n2.SEARCH\n3.UPDATE\n4.SHOW\n5.EXIT\nEnter your choice:");
scanf("%d",&choice);
switch(choice)
{
case 1:insert();
break;
case 2:search();
break;
case 3:update();
break;
case 4:show();
break;
case 5:exit(0);
break;
default:printf("Wrong choice\n");
}
}
}

void insert()
{
if(status==0)
{
printf("File not Exist\n");
}
else
{
status=1;
fp=open(fname,O_CREAT | O_WRONLY);
if(fp==-1)
printf("error....\n");
lseek(fp,0,SEEK_END);
printf("Enter student details\n");
printf("Roll NO:");
scanf("%d",&s1.rno);
printf("Name:");
scanf("%s",s1.name);
write(fp,&s1,sizeof(s1));
}
}

void search()
{
if(status==0)
{
printf("File does not exist\n");
}
else
{
int r,flag=0;
printf("Enter the roll no to search:");
scanf("%d",&r);
fp=open(fname,O_RDONLY);
if(fp==-1)
printf("error....\n");
while(read(fp,&s2,sizeof(s2))!=0)
{
if(s2.rno==r)
{
flag=1;
printf("Element found\n");
printf("Roll NO:%d\nName:%s\n",s2.rno,s2.name);
}
}
if(flag==0)
printf("Not Found\n");
}
}

void update()
{
if(status==0)
{
printf("File does not exist\n");
}
else
{
int r,n=0,flag=0;
printf("Enter the Roll NO to Update:");
scanf("%d",&r);
fp=open(fname,O_RDWR);
if(fp==-1)
printf("error....\n");
while(read(fp,&s2,sizeof(s2))!=0)
{
n++;
if(s2.rno==r)
{
n--;
printf("Enter new Roll NO:");
scanf("%d",&s1.rno);
printf("Enter new Name:");
scanf("%s",s1.name);
lseek(fp,n*sizeof(s1),SEEK_SET);
write(fp,&s1,sizeof(s1));
flag=1;
break;
}
}
if(flag==0)
printf("Student not found\n");
}
}

void show()
{
if(status==0)
{
printf("File does not exist\n");
}
else
{
printf("File contains\nRoll NO\tName\n");
fp=open(fname,O_RDONLY);
if(fp==-1)
printf("error....\n");
while(read(fp,&s2,sizeof(s2))!=0)
{
printf("%d\t%s\n",s2.rno,s2.name);
}
}
}


*****FTP (CLIENT)*****

#include
#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser;
int r=1,fd,s;
char fname[50],c[50],buf[500];
s=socket(AF_INET,SOCK_STREAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
connect(s,(struct sockaddr*)&ser,sizeof(ser));
printf("enter the file name");
scanf("%s",fname);
send(s,fname,strlen(fname)+1,0);
recv(s,c,7,0);
if(strcmp(c,"exists")!=0)
printf("requested file is in save.c");
else
{
fd=open("save.c", O_CREAT|O_WRONLY,S_IWUSR|S_IRUSR);
if(fd==-1)
printf("cannot open theis file");
else
{
while(r!=0)
{
bzero(buf,500);
r=recv(s,buf,499,0);
write(fd,buf,499);
fflush(stdin);
}
close(fd);
printf("the required file is in save.c");
}
}
close(s);
}


*****FTP (SERVER)*****

#include
#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser,cli;
int fd,s,n,sock;
char b[10],a[10],c[]="failed",e[]="exist",buf[500];
s=socket(AF_INET,SOCK_STREAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
bind(s,(struct sockaddr*)&ser,sizeof(ser));
listen(s,5);
n=sizeof(cli);
sock=accept(s,(struct sockaddr*)&cli,&n);
bzero(b,10);
recv(sock,b,9,0);
fd=open(b,O_RDONLY);
if(fd==-1)
send(sock,c,strlen(c)+1,0);
else
{
send(sock,e,strlen(e)+1,0);
while(read(fd,buf,sizeof(buf))!=0)
{
send(sock,buf,499,0);
bzero(buf,500);
}
close(fd);
}
close(sock);
close(s);
}


*****TCP (CLIENT)*****

#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser;
int s;
char d[500],a[500],b[]="exit";
s=socket(AF_INET,SOCK_STREAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
connect(s,(struct sockaddr*)&ser,sizeof(ser));
while(1)
{
printf("/n enter the message:");
scanf("%s",a);
send(s,a,sizeof(a),0);
if(strcmp(a,b)==0)
break;
recv(s,d,sizeof(d),0);
if(strcmp(d,b)==0)
break;
printf("message form server:");
printf("%s",d);
}
close(s);
}



*****TCP (SERVER)*****

#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser,cli;
int s,cn,sock,n;
char d[500],a[500],b[]="exit";
s=socket(AF_INET,SOCK_STREAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
bind(s,(struct sockaddr*)&ser,sizeof(ser));
listen(s,5);
n=sizeof(cli);
sock=accept(s,(struct sockaddr*)&cli,&n);
while(1)
{
recv(sock,d,sizeof(d),0);
if(strcmp(d,b)==0)
break;
printf("/n/n message from clients");
printf("%s",d);
printf("enter the message:");
scanf("%s",a);
send(sock,a,sizeof(a),0);
if(strcmp(a,b)==0)
break;
}
close(sock);
close(s);
}



*****TELENT (CLIENT)*****

#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser;
struct timeval t;
int s,fd,n;
char a[50],b[100];
s=socket(AF_INET,SOCK_STREAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
t.tv_sec=0;
t.tv_usec=100000;
setsockopt(s,SOL_SOCKET,SO_RCVTIMEO,&t,sizeof(t));
connect(s,(struct sockaddr*)&ser,sizeof(ser));
setbuf(stdout,NULL);
while(1)
{
printf("telnet>\n");
bzero(a,50);
gets(a);
send(s,a,strlen(a)+1,0);
if((strcmp(a,"exit")==0)||(strcmp(a,"quit")==0))
break;
while(1)
{
bzero(b,100);
n=recv(s,b,95,0);
if(n>=0)
{
printf("%s",b);
if(n<=1)
break;
}
else
break;
}
}
close(s);
}


*****TELNET (SERVER)*****

#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser,cli;
int s,sock,c,n;
char command[20];
s=socket(AF_INET,SOCK_STREAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
bind(s,(struct sockaddr*)&ser,sizeof(ser));
listen(s,5);
n=sizeof(cli);
while(1)
{
c=accept(s,(struct sockaddr*)&cli,&n);
dup2(c,1);
dup2(c,2);
while(1)
{
bzero(command,20);
recv(c,command,19,0);
if(!(strcmp(command,"quit"))||!(strcmp(command,"exit")))
break;
system(command);
}
close(c);
}
close(s);
}


*****UDP (CLIENT)*****

#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser;
int s,n,len;
char b[50],a[50],e[]="exit";
s=socket(AF_INET,SOCK_DGRAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
while(1)
{
printf("\n enter the message to be send:");
scanf("%s",b);
sendto(s,b,strlen(b)+1,0,(struct sockaddr*)&ser,sizeof(ser));
if(strcmp(b,e)==0)
break;
n=sizeof(ser);
recvfrom(s,a,10,0,(struct sockaddr*)&ser,&n);
if(strcmp(a,e)==0)
break;
printf("message from server:");
printf("%s",a);
}
close(s);
}




*****UDP (SERVER)*****

#include
#include
#include
#include
#include
#include
main()
{
struct sockaddr_in ser,cli;
int s,len,n;
char b[50],a[50],e[]="exit";
s=socket(AF_INET,SOCK_DGRAM,0);
ser.sin_family=AF_INET;
ser.sin_port=5000;
ser.sin_addr.s_addr=inet_addr("127.0.0.1");
bind(s,(struct sockaddr*)&ser,sizeof(ser));
while(1)
{
n=sizeof(cli);
recvfrom(s,a,10,0,(struct sockaddr*)&cli,&n);
if(strcmp(a,e)==0)
break;
printf("\n\n recieved message from client:");
printf("%s",a);
printf("enter the message:");
scanf("%s",b);
len=strlen(b);
sendto(s,b,len+1,0,(struct sockaddr*)&cli,sizeof(cli));
if(strcmp(b,e)==0)
break;
}
close(s);
}