gethostbyaddr problem - C / C++ / MFC Discussion Boards

Iceman16-Apr-03 2:50

16-Apr-03 2:50

Thanks for the info. The back buffer is processed by the paint routine in the main thread as well. What's the best way to handle multi-threaded graphics to a dialog window?

Re: Multi-threaded graphics

Iceman16-Apr-03 2:57

Iceman

16-Apr-03 2:57

Maybe I can explain it better. Only the main thread that created the dialog processes messages. The worker thread only updates only the back buffer which is then processed by the main thread and updated to the screen.

Weird run-time error

will138315-Apr-03 10:25

will1383

15-Apr-03 10:25

Hi all,

I've created a release version of an application which uses MFC and when deployed on my test machine I get the error:

"The dynamic link library MSVC60.dll could not be found in the specified path ...."

I know what the error means, but why in the heck is it looking for this file? I thought the release build was independent of the Visual Studio dlls. What do I need to do in order to correct this problem?

Re: Weird run-time error

C^hris L^osinger15-Apr-03 10:35

C^hris L^osinger

15-Apr-03 10:35

will1383 wrote:
I thought the release build was independent of the Visual Studio dll

only if you build with static linking. (Project / Settings / General - in VC6)

-c

Image tools: ThumbNailer, Bobber, TIFFAssembler

Re: Weird run-time error

will138315-Apr-03 10:38

will1383

15-Apr-03 10:38

What's really strange though is that I've been using dynamic linking all along, and have had no problems what-so-ever.

Strange. I'll try a static build for kicks.

Re: Weird run-time error

Joe Woodbury15-Apr-03 14:00

Joe Woodbury

15-Apr-03 14:00

The debug DLL (MSVC60D.DLL) may be installed but not the non-debug DLL.

Re: Weird run-time error

Beer15-Apr-03 13:21

Beer

15-Apr-03 13:21

use the visual studio installer, and include msvc60 as a merge module, that should solve your problem right there.

hey

gethostbyaddr problem

Tom Wright15-Apr-03 10:20

Tom Wright

15-Apr-03 10:20

I'm writing a program that gets a computer name from a list of IP address. The first time thru it gets the computer name without a hitch. From then on I keep getting a error.
Here is a snippet of my code that does the gethostbyaddr.

}<br />
	LPHOSTENT lphp;<br />
	struct in_addr in_addrIP;<br />
<br />
	//char szBuffName[80];<br />
<br />
	<br />
	if (!InitSocket()) <br />
	{<br />
		AfxMessageBox("Error initializing WSAStartup", MB_OK | MB_ICONSTOP);<br />
		return -1;<br />
	}<br />
	<br />
	in_addrIP.S_un.S_addr = inet_addr(szAddress);<br />
	lphp = gethostbyaddr((char FAR *)&in_addrIP, sizeof(struct in_addr), PF_INET);<br />
<br />
	if (lphp == NULL)<br />
	{<br />
		AfxMessageBox("Failed at gethostbyaddr", MB_OK | MB_ICONSTOP);<br />
		return -1;<br />
	}<br />
	<br />
	WSACleanup();<br />
<br />
	return lphp->h_name;<br />
<br />
	//return 1;<br />
<br />
}

Am I supposed to initialize something before I give it another address to try?

Thanks

Tom Wright
tawright915@yahoo.com

Re: gethostbyaddr problem

valikac15-Apr-03 11:09

valikac

15-Apr-03 11:09

Yes, you must reinitialize winsock after WSACleanup().

Kuphryn

Re: gethostbyaddr problem

Tom Wright15-Apr-03 11:12

Tom Wright

15-Apr-03 11:12

I am. Each time I drop into this fuction it runs the InitSocket().

Tom Wright
tawright915@yahoo.com

Re: gethostbyaddr problem

David Crow16-Apr-03 2:24

David Crow

16-Apr-03 2:24

Which does what? The counterpart to WSACleanup() is WSAStartup(). If your "convert" function is being called multiple times, I'd move the calls to WSACleanup() and WSAStartup() so they are only called once.

Re: gethostbyaddr problem

Tom Wright16-Apr-03 3:42

Tom Wright

16-Apr-03 3:42

Understandable. I'll try that. Although that should not make a difference since each time I come out of this function I clean up the socket. And each time I come into it with a new ip address, it's initialized.
There may be some resouce overhead with doing it this way which is why I may take up your suggestion and move it out of this function and only do it once, but this still does not fix my problem.

Any other suggestions?

Thanks

Tom Wright
tawright915@yahoo.com

Re: gethostbyaddr problem

David Crow16-Apr-03 3:53

David Crow

16-Apr-03 3:53

Tom Wright wrote:
Any other suggestions?

Not without knowing what InitSocket() does. If it calls WSAStartup(), which might be failing, what does WSAGetLastError() return?

In your original post, you state that "From then on I keep getting a error." but give no indication as to the error or the line causing it.

inet_addr() can return INADDR_NONE but there is no check for that.

gethostbyaddr() can return any number of errors, but none are being checked for. Call WSAGetLastError() to find out.

Re: gethostbyaddr problem

Tom Wright16-Apr-03 4:42

Tom Wright

16-Apr-03 4:42

David
Thanks for the quick response.

InitSocket =

<br />
	WSADATA wsaData;<br />
	int retVal = NULL;<br />
	<br />
	retVal = WSAStartup(MAKEWORD(2,2), &wsaData);<br />
	<br />
	if(retVal)<br />
	{<br />
		return -1;<br />
	}<br />
	<br />
	return 1;<br />

If initsocket comes back with a -1 then WSAStartup failed.

DavidCrow wrote:
In your original post, you state that "From then on I keep getting a error." but give no indication as to the error or the line causing it.

Yeah sorry for the confusion. Basically it's failing at the gethostbyaddr.

I guess I wasn't that clear in my subject line.

I haven't done a WSAGetLastError...brain freeze or something.

The way this app works is that I have a list of IP address. I get the first IP address and ping it. If it response then I drop down to this function and get the computer name. Then come back to my calling function and get the next IP address. Ping it and if there is a response then I drop down to this fuction. If there is no response then drop to some other function.
My problem is that the very first time it comes to this function is works fine and returns back the computer name. The second, third, fourth, etc times it comes to this function it errors out.

I'll run the WSAGetLastError and see what I get returned back. I just thought that I need to initialize somthing that I wasn't

Thanks for the help

Tom Wright
tawright915@yahoo.com

Re: gethostbyaddr problem

Tom Wright16-Apr-03 5:05

Tom Wright

16-Apr-03 5:05

David
I found my problem. Sometimes I feel really stupid.

First I put in my error checking function that calls WSAGetLastError. After it started going down my list of IP addresses it errored out after the first one with a strange error. After reading the error I realized....what if the ip addresses at the beginning of the list did not have a NETBIOS name?

So after looking at the ip addresses and trying different ones that I was sure was associates with a pc it worked fine. After further searching I found that the ones (ip addresses) that were erroring out were ones associated to ras servers and print servers. Not pc's but like the jet direct print server. DUH!!! I can't believe that I overlooked that.

Thanks for all the help. Sometimes it's worth posting on this forum just so that someone can give you that differnt look at the problem.

Thanks again

Tom Wright
tawright915@yahoo.com

File Comparisons

Colin Davidson15-Apr-03 10:06

Colin Davidson

15-Apr-03 10:06

Hi,
I asked this question a long while ago but all the suggestions were too complex for a beginner like me :P

anyway, basically, what is the easiest way to compare two files, given just their path names.

The best one i found on here seemed to have about 500 compilation warnings... vDiff i think it was called..

it's for a windows only program btw, if that makes a difference.

Thanks in advance, you could be lifesavers.

cheers

Col

Re: File Comparisons

Joe Woodbury15-Apr-03 14:02

Joe Woodbury

15-Apr-03 14:02

The simplest is from the command line type:

fc /b file1 file2

(Of course, replace file1 and file2 with the appropriate file names.)

Edit Ctrl Style(ES_CENTER)

Mr. Maan15-Apr-03 9:53

Mr. Maan

15-Apr-03 9:53

Hi Guys,
I am facing a problem while playing with different styles of the Edit Control. I want to toggle between the alignement styles ES_LEFT,ES_RIGHT and ES_CENTER at run time through selecting them through radio buttons. I have tried to do it through the following code, but it does't work in case of above stated style bit whereas the same code
works correct for ES_LOWERCASE and ES_UPPERCASE bits;

//To switch to centered alignment <br />
	DWORD	dwStyleOld;<br />
	DWORD	dwStyleNew;<br />
	CRect   rect;<br />
	dwStyleOld = m_EditCtrl.GetStyle();<br />
	dwStyleNew = dwStyleOld & ~ES_LEFT;<br />
        dwStyleNew = dwStyleNew | ES_CENTER;<br />
	m_EditCtrl.ModifyStyle(dwStyleOld, dwStyleNew);<br />
	m_EditCtrl.GetWindowRect(&rect);<br />
	InvalidateRect(&rect);

Regards,
Nasir Maan

Re: Edit Ctrl Style(ES_CENTER)

Miszou15-Apr-03 10:54

Miszou

15-Apr-03 10:54

Try something like this instead:

<br />
DWORD dwStyle = GetWindowLong( GWL_STYLE );<br />
dwStyle &= ~ES_LEFT;<br />
dwStyle |= ES_CENTER;<br />
SetWindowLong( GWL_STYLE, dwStyle );<br />

There are 10 kinds of people - those that get binary and those that don't.

Re: Edit Ctrl Style(ES_CENTER)

Mr. Maan15-Apr-03 11:14

Mr. Maan

15-Apr-03 11:14

sir,
I have tried it also...but unfortunately there is no success.

Regards,
Nasir

Re: Edit Ctrl Style(ES_CENTER)

Gary R. Wheeler18-Apr-03 5:35

Gary R. Wheeler

18-Apr-03 5:35

Try this instead:

m_EditCtrl.ModifyStyle((ES_LEFT | ES_CENTER | ES_RIGHT),ES_CENTER);

The first argument to ModifyStyle are the styles to be removed, and the second argument are the styles to set. So ModifyStyle does the 'and-not' and 'or' operations for you.

Software Zen: delete this;

string, map STL problem

Matthew Fleming15-Apr-03 8:55

Matthew Fleming

15-Apr-03 8:55

Netmeisters,

I am trying to do something which should be simple. Using Visual C++ I want to create a map containing an STL string as a key and my own type as a value.

#include <string>
#include <map>
#include <iostream>

using namespace std;
map<string,CReport>slips;

Then to add a pair to the map:

string str;
pair<map<string,CReport>::iterator, bool> ret =
slips.insert(map<string,CReport>::value_type(str,report));

But this produces a host of error messages that I've included below.
Can't figure these out at all. When I comment out the pair<map etc line the messages go away.

Any assistance much appreciated.

Matthew Fleming
mgf@mcw.edu

c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(138) : while compiling class-template member function 'bool std::less<_Ty>::operator ()(const _Ty &,const std::string &) const'
with
[
_Ty=std::string
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\map(36) : see reference to class template instantiation 'std::less<_Ty>' being compiled
with
[
_Ty=std::string
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\xtree(19) : see reference to class template instantiation 'std::_Tmap_traits<_Kty,_Ty,_Pr,_Alloc,_Mfl>' being compiled
with
[
_Kty=std::string,
_Ty=CReport,
_Pr=std::less<std::string>,
_Alloc=std::allocator<std::pair<const std::string,CReport>>,
_Mfl=false
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\xtree(61) : see reference to class template instantiation 'std::_Tree_nod<_Traits>' being compiled
with
[
_Traits=std::_Tmap_traits<std::string,CReport,std::less<std::string>,std::allocator<std::pair<const std::string,CReport>>,false>
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\xtree(83) : see reference to class template instantiation 'std::_Tree_ptr<_Traits>' being compiled
with
[
_Traits=std::_Tmap_traits<std::string,CReport,std::less<std::string>,std::allocator<std::pair<const std::string,CReport>>,false>
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\xtree(101) : see reference to class template instantiation 'std::_Tree_val<_Traits>' being compiled
with
[
_Traits=std::_Tmap_traits<std::string,CReport,std::less<std::string>,std::allocator<std::pair<const std::string,CReport>>,false>
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\map(77) : see reference to class template instantiation 'std::_Tree<_Traits>' being compiled
with
[
_Traits=std::_Tmap_traits<std::string,CReport,std::less<std::string>,std::allocator<std::pair<const std::string,CReport>>,false>
]
c:\Palm\dpCold\DpCGenCond.cpp(201) : see reference to class template instantiation 'std::map<_Kty,_Ty,_Pr,_Alloc>' being compiled
with
[
_Kty=std::string,
_Ty=CReport,
_Pr=std::less<std::string>,
_Alloc=std::allocator<std::pair<const std::string,CReport>>
]
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::list<_Ty,_Alloc> &,const std::list<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::list<_Ty,_Ax> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::list<_Ty,_Alloc> &,const std::list<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::list<_Ty,_Ax> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::list<_Ty,_Alloc> &,const std::list<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::list<_Ty,_Ax> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::_Ptrit<_Ty,_Diff,_Pointer2,_Reference2,_Pointer2,_Reference2> &,const std::_Ptrit<_Ty,_Diff,_Pointer,_Reference,_Pointer2,_Reference2> &)' : could not deduce template argument for 'const std::_Ptrit<_Ty,_Diff,_Pointer2,_Reference2,_Pointer2,_Reference2> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::_Ptrit<_Ty,_Diff,_Pointer2,_Reference2,_Pointer2,_Reference2> &,const std::_Ptrit<_Ty,_Diff,_Pointer,_Reference,_Pointer2,_Reference2> &)' : could not deduce template argument for 'const std::_Ptrit<_Ty,_Diff,_Pointer2,_Reference2,_Pointer2,_Reference2> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::_Ptrit<_Ty,_Diff,_Pointer2,_Reference2,_Pointer2,_Reference2> &,const std::_Ptrit<_Ty,_Diff,_Pointer,_Reference,_Pointer2,_Reference2> &)' : could not deduce template argument for 'const std::_Ptrit<_Ty,_Diff,_Pointer2,_Reference2,_Pointer2,_Reference2> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string'
c:\Program Files\Microsoft Visual Studio .NET\Vc7\include\functional(139) : error C2676: binary '<' : 'const std::string' does not define this operator or a conversion to a type acceptable to the predefined operator

Re: string, map STL problem

Ben Burnett15-Apr-03 9:18

Ben Burnett

15-Apr-03 9:18

It compiles fine for me, are you sure it's not some other thing that is causing the trouble? Maybe post some of the code surrounding this snippet.

cheers,
-B

Re: string, map STL problem

jhwurmbach15-Apr-03 21:38

jhwurmbach

15-Apr-03 21:38

For extracting the essence out of these weired error-messages, you can try using STLError Decryptor[^]

For me, it works fine - and it is free Smile | :)

My opinions may have changed, but not the fact that I am right.

Re: string, map STL problem

richard_k1-Jun-10 15:19

richard_k

1-Jun-10 15:19

You must make sure you have an #include <string> in your source file. Frequently you'll get things to compile with the declarations looking fine, but when usages start if the actual include isn't there then the compiler doesn't know what to do. I think this is being caused by the underlying compiler mechanics of how it instantiates templates.

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