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LValue ?

 
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LValue ?, I keep getting this error
UG Cyber
4 Aug, 2008 - 08:49 PM
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Well i am trying to make the same Chat program user friendly for one of my buddys (this sucks, I'm not even getting paid for all of this trouble mad.gif ) However i think it would be in my best interest to find out what 'LValue' is.... Here is the lines that its having problems with
CODE

char IP[30];
IP = gethostbyname(Host);
error=WSAStartup(0x0202, &wsadata);


It brings me just after the '=' when i try to get host by its name and says

[C++ Error] Unit1.cpp(26): E2277 Lvalue required

I'm using Borland Builder 6
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Martyr2
RE: LValue ?
4 Aug, 2008 - 09:25 PM
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I believe gethostbyname actually returns a pointer to a hostent structure. Not a char array. Check out the function again and change it accordingly.LValue is the value on the left hand side of the equals sign.

smile.gif
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UG Cyber
RE: LValue ?
5 Aug, 2008 - 07:58 AM
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QUOTE(Martyr2 @ 4 Aug, 2008 - 10:25 PM) *

I believe gethostbyname actually returns a pointer to a hostent structure. Not a char array. Check out the function again and change it accordingly.LValue is the value on the left hand side of the equals sign.

smile.gif


Ok that got pass the LValue error but how do i convert that to a char* so i can use the hostent to connect to the client??
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Hyper_Eye
RE: LValue ?
5 Aug, 2008 - 12:46 PM
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QUOTE(UG Cyber @ 5 Aug, 2008 - 10:58 AM) *

QUOTE(Martyr2 @ 4 Aug, 2008 - 10:25 PM) *

I believe gethostbyname actually returns a pointer to a hostent structure. Not a char array. Check out the function again and change it accordingly.LValue is the value on the left hand side of the equals sign.

smile.gif


Ok that got pass the LValue error but how do i convert that to a char* so i can use the hostent to connect to the client??


The gethostbyname() man page has the definition of the hostent structure in it. h_addr_list is what your looking for.
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UG Cyber
RE: LValue ?
5 Aug, 2008 - 01:22 PM
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Ok so i would have to type this in??
CODE

struct hostent* host;
host = gethostbyname("192.168.0.1");
sock.sin_family = AF_FAMILY;
sock.sin_port = htons(portNo);
sock.sin_addr.s_addr = host(h_addr);


??
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Hyper_Eye
RE: LValue ?
5 Aug, 2008 - 02:32 PM
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QUOTE(UG Cyber @ 5 Aug, 2008 - 04:22 PM) *

Ok so i would have to type this in??
CODE

struct hostent* host;
host = gethostbyname("192.168.0.1");
sock.sin_family = AF_FAMILY;
sock.sin_port = htons(portNo);
sock.sin_addr.s_addr = host(h_addr);


??


Try

CODE
sock.sin_addr.s_addr = *((struct in_addr *)host->h_addr);


You may find this site helpful when it comes to socket programming: http://www.beej.us/guide/bgnet/
It is a very popular guide.

This post has been edited by Hyper_Eye: 5 Aug, 2008 - 02:33 PM
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