error using sendto

c++.prog.newbie · 03-16-2006, 01:41 PM

when i use sento (UDP) in my program trying to send a mesg from one computer to the same one i get this error

sendto: Can't assign requested address

i tried 127.0.0.1 and the actual IP address but both give the same error

here is the code were i set the addr and use sendto

Code:

        tempaddr.sin_family = AF_INET;
        tempaddr.sin_port = htons(0);
        tempaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
        memset(&(tempaddr.sin_zero), '\0', 8);

        if((sent = sendto(localsock, argv[2], MAXMSGSIZE-1, 0, (struct sockaddr *)&tempaddr, sin_size)) == -1)
        {
            perror("sendto");
            return -1;
        }

anyone know how to solve this problem? or what im doing wrong

c++.prog.newbie · 03-16-2006, 04:46 PM

actually i got a different problem,

how do i get the address from a hostent* (h->h_addr) into a myaddr.sin_addr.s_addr ?

c++.prog.newbie · 03-20-2006, 02:16 AM

ok i got that problem figured out, im still getting the error
sendto: Invalid argument
which is printed out using perror("sendto")...
i tried entering the following code for debugging purposes

Code:

cout<<"h_addr_list[0] is: "<<h->h_addr_list[0]<<endl; // same as h_addr
cout<<"h_name is: "<<h->h_name<<endl;
cout<<"h_aliases[0] is: "<<h->h_aliases[0]<<endl;
cout<<"h_addrtype is: "<<h->h_addrtype<<endl;
cout<<"h_length is: "<<h->h_length<<endl;

and if i leave the line with h_aliases uncommented it seems that the program will skip everything until it gets to sendto... which it then prints out the error that i stated above...
if i comment out the aliases line i get the following output

Code:

[adam@d198-53-226-104 ~]$ ./cs d198-53-226-104.abhsia.telus.net help
h_addr_list[0] is: \uffff5
h_name is: d198-53-226-104.abhsia.telus.net
h_addrtype is: 2
h_length is: 4
addr is: 198.53.226.104
sendto: Invalid argument

any idea how to solve this?? i would appreciate any help

03-16-2006, 01:41 PM	#1
c++.prog.newbie Registered User Join Date: Oct 2001 Posts: 224	error using sendto when i use sento (UDP) in my program trying to send a mesg from one computer to the same one i get this error sendto: Can't assign requested address i tried 127.0.0.1 and the actual IP address but both give the same error here is the code were i set the addr and use sendto Code: tempaddr.sin_family = AF_INET; tempaddr.sin_port = htons(0); tempaddr.sin_addr.s_addr = inet_addr("127.0.0.1"); memset(&(tempaddr.sin_zero), '\0', 8); if((sent = sendto(localsock, argv[2], MAXMSGSIZE-1, 0, (struct sockaddr )&tempaddr, sin_size)) == -1) { perror("sendto"); return -1; } anyone know how to solve this problem? or what im doing wrong Last edited by c++.prog.newbie; 03-16-2006 at 03:59 PM.*
c++.prog.newbie is offline

03-16-2006, 04:46 PM	#2
c++.prog.newbie Registered User Join Date: Oct 2001 Posts: 224	actually i got a different problem, how do i get the address from a hostent* (h->h_addr) into a myaddr.sin_addr.s_addr ?
c++.prog.newbie is offline

03-20-2006, 02:16 AM	#3
c++.prog.newbie Registered User Join Date: Oct 2001 Posts: 224	ok i got that problem figured out, im still getting the error sendto: Invalid argument which is printed out using perror("sendto")... i tried entering the following code for debugging purposes Code: cout<<"h_addr_list[0] is: "<<h->h_addr_list[0]<<endl; // same as h_addr cout<<"h_name is: "<<h->h_name<<endl; cout<<"h_aliases[0] is: "<<h->h_aliases[0]<<endl; cout<<"h_addrtype is: "<<h->h_addrtype<<endl; cout<<"h_length is: "<<h->h_length<<endl; and if i leave the line with h_aliases uncommented it seems that the program will skip everything until it gets to sendto... which it then prints out the error that i stated above... if i comment out the aliases line i get the following output Code: [adam@d198-53-226-104 ~]$ ./cs d198-53-226-104.abhsia.telus.net help h_addr_list[0] is: \uffff5 h_name is: d198-53-226-104.abhsia.telus.net h_addrtype is: 2 h_length is: 4 addr is: 198.53.226.104 sendto: Invalid argument any idea how to solve this?? i would appreciate any help Last edited by c++.prog.newbie; 03-20-2006 at 02:19 AM.
c++.prog.newbie is offline

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