Member Avatar for shre86

I am trying to develop a basic communicating link using windows sockets in visual studio.net2003... but it is showing an lnk2001 error.. is it necessary that have to get the platform SDK and install it before i can use winsock2.h????

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As pointed out, the LNK2001 errors mean the Winsock import library is not being linked. The Platform (Windows) SDK is not required just to use the standard Winsock2 API — Visual Studio normally provides the headers and the import library — but the SDK can be installed if those files are missing or if newer socket APIs are needed.

To add the library in Visual Studio .NET 2003: open the Project Properties for the active configuration, find the Linker settings and the Input (or Additional Dependencies) field, and add Ws2_32.lib. Apply the change to the correct configuration (Debug/Release) or to All Configurations so both builds see the library. If the linker reports it cannot find the file, add the VC/lib or SDK \Lib folder to the Linker -> General -> Additional Library Directories. For older project formats, the same library can be added via Project -> Settings -> Linker -> Object/library modules.

As a convenient in-code alternative (avoids touching project pages), place the following once in a source file:

#pragma comment(lib, "Ws2_32.lib")

Also note two common pitfalls that cause follow-up problems: include <winsock2.h> before <windows.h> (or #define WIN32_LEAN_AND_MEAN before including windows.h) to prevent conflicts with winsock.h, and initialize the Winsock subsystem with WSAStartup(MAKEWORD(2,2), &wsaData) before any socket calls and call WSACleanup() when finished. Once the correct import library is linked for the active configuration, the unresolved externals in the build log should be resolved.

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Member Avatar for winbatch

You probably just need to incude the appropriate .lib in your studio project. Without the link error, I don't know which .lib...)

Member Avatar for shre86

You probably just need to incude the appropriate .lib in your studio project. Without the link error, I don't know which .lib...)

this is the link error it is showing:

Linking...
a.obj : error LNK2001: unresolved external symbol "int __stdcall connect(unsigned int,struct sockaddr const *,int)" (?connect@@$$J212YGHIPBUsockaddr@@H@Z)
a.obj : error LNK2001: unresolved external symbol "unsigned short __stdcall htons(unsigned short)" (?htons@@$$J14YGGG@Z)
a.obj : error LNK2001: unresolved external symbol "unsigned long __stdcall inet_addr(char const *)" (?inet_addr@@$$J14YGKPBD@Z)
a.obj : error LNK2001: unresolved external symbol "int __stdcall WSACleanup(void)" (?WSACleanup@@$$J10YGHXZ)
a.obj : error LNK2001: unresolved external symbol "int __stdcall WSAGetLastError(void)" (?WSAGetLastError@@$$J10YGHXZ)
a.obj : error LNK2001: unresolved external symbol "unsigned int __stdcall socket(int,int,int)" (?socket@@$$J212YGIHHH@Z)
a.obj : error LNK2001: unresolved external symbol "int __stdcall WSAStartup(unsigned short,struct WSAData *)" (?WSAStartup@@$$J18YGHGPAUWSAData@@@Z)
H:\Project\work\aa\Debug\aa.exe : fatal error LNK1120: 7 unresolved externals

Build log was saved at "file://h:\Project\work\aa\aa\Debug\BuildLog.htm"
aa - 8 error(s), 0 warning(s)


pls help....

Member Avatar for winbatch

You have to link with:

Ws2_32.lib.

Member Avatar for shre86

You have to link with:

Ws2_32.lib.

could u pls tell me how i do that.. i am a beginner so have lots to learn

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