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Hi
I am wondering if anyone can point me in the right direction
I am getting strange results
When I try to move a DWORD to a char[4] I am running in 64 bit mode and it my understanding that both are 32 bits long
The DWORD has 4 bytes of a ebcdic character string
I want to move the DWORD to char 4 so that I can access every character and convert it to ascii when I try to move 1 of the chars to a unsigned int e.g. Unsigned int c = str[1] the result in c is a negative number maybe the high order bit in str[1] byte is on but by moving it to a unsigned int shouldn't that do away with making the result negative for example moving a D0 results in FFF2
Any help appreciated
Thanks
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I think the problem comes from the way bytes are ordered in memory.
When you treat a 4-byte block as a DWORD, the bytes are not in order from MSB to LSB. It depends upon your hardware.
You can verify this in the debugger. Place a breakpoint anywhere you are using the DWORD variable, and then when it breaks, switch to Disassembly view. (Make sure "Show code bytes" is on.) You'll see the way the bytes are ordered, and it's not what you expect!
The difficult we do right away...
...the impossible takes slightly longer.
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That must be it I am doing coding on Hercules MainFrame Emulator when using C Windows function that data doesn't comes back in inverse order
Thanks
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In this case we have to implement an algorithm for packing 4 bytes to a single dword programmatically.
Also, there's no default conversion. DWORD data type is 32 bits = 4 bytes long regardless of it's x64 or x86 mode. 
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Hercules has a function FETCH_FW which will take a MainFrame fullword 4 bytes and put in the right sequence for Windows/Linux However it is still coming in EBCDIC and I need to convert it to ASCII thus I need to access every byte and convert it the function FETCH_FW takes as 1st param a DWORD I thought using unsigned char[4] would produce the same result apparently not
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Hi,
How to call C# callback function from VC++ dll?
In my project dll was developed in VC++ and it was
accessed by c# application.
Now I want to call callback function in C# application when particular event was occur in VC++ dll.
Thanks in advance.
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I am developping USB Driver using UMDF1.9 for XP now
I need to reset USB devide from my driver. So I am going to use IOCTL_USB_Hub_Recycle_port to simulate plug off/on.
Does somebody have smaple code hpw to call IOCTL_USB_Hub_Recycle_port
Thanks
Henry
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Does this point you in the right direction?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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Hello everyone..
I'm currently doing my Masters in Computer Network Engg and I have decided to do my Final semester project in optimisation of firewalls.
I'm thinking of implementing firewall optimisation using rule re-ordering and rule conflict detection, but I don't have a clue on how to get started.
I got to know that I can make use of Windows Firewall API (NetFwTypeLib) and work on top of Windows Firewall but I'm not quite sure if this would help me or not.
If you have done anything similar or have some pointers for me please guide me.
Thanks..
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SujithKG wrote: I don't have a clue on how to get started.
Try doing some research into the subject, or choose something you do have a clue about.
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//print function
CString fmt(double db)
{
CString cs;
cs.Format("%f", db);
return cs;
}
//problem
void TheDlg::Test00()
{
const double dbInf = 1.0/::sin(0);
const double dbZero = (::fabs(::cos(3.14159/2))<0.9)?0:1;
CString cs;
cs += fmt(dbZero)+"\r\n";
cs += fmt(dbZero * dbInf)+"\r\n";
cs += fmt(0 * dbInf)+"\r\n";
MessageBox(cs);
}
above dbZero only has 2 possible values : 0 or 1 - see line 1;
output:
0.000000
-1.#IND00
0.000000
output of line 2 shows that dbZero is zero.
output of line 3 shows that dbZero is not zero, since it is different from output of line 4.
funny thing is that if change line 1 to:
const double dbZero = (0.1<0.9)?0:1;
Then all outputs are zeros.
Why?
How to make dbZero as a true zero in problem code?
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Floating point numbers are not exact. See: Comparing Floats[^]
The difficult we do right away...
...the impossible takes slightly longer.
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Just got a more consistent behaviour on Linux:
#include <cstdio>
#include <cmath>
void out_double( double db )
{
printf("%f\n", db);
}
int main()
{
const double dbInf = 1.0/::sin(0); const double dbZero = (::fabs(::cos(3.14159/2))<0.9)?0:1;
out_double( dbZero );
out_double( dbZero * dbInf );
out_double( 0 * dbInf );
}
outputs
0.000000
-nan
-nan
[update]
The same program, on Windows 8, compiled with Visual Studio 2012, produces
0.000000
-1.#IND00
-1.#IND00
[/update]
modified 28-Dec-15 16:54pm.
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Hey there !!
LOOK OUT - LOOK OUT - LOOK OUT - LOOK OUT -
The problem is NOT on the dbZero - but on the dbInf. 
That explains everything you see.
dbInf is 1 divided by zero, which is undefined.
Anytime you try to use this value, you´ll have problems.
That´s why you CAN print dbZero, but not dbInf or (dbZero * dbInf).
Ok ?
modified 21-Jan-16 14:44pm.
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Greetings,
I have a database creation script. I've run the script after changed the path within the 'FILENAME' option to create the database on an external hard disk and I was able to see and select data from tables as the script run with no errors. However, when I tried to connect to the database from an application and read data from database tables, an exception thrown for SQL Server error 823 "The operating system returned error 21(The device is not ready.) to SQL Server during a read at offset 0x00000000132000 in file 'Database name'. Additional messages in the SQL Server error log and system event log may provide more detail. This is a severe system-level error condition that threatens database integrity and must be corrected immediately. Complete a full database consistency check (DBCC CHECKDB). This error can be caused by many factors; for more information, see SQL Server Books Online.". I've tried to run database consistency commands against it but they did not carried out and I got an error message. Also when I tried to drop or recover the database, dropping and recovering process failed. Finally, I had to make the database offline then I dropped it. I need to create such database on my external hard disk not on my primary one. Can anyone help?!!!
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This has nothing to do with C/C++. Please use the Database forum.
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Yeah sure I know. It is my fault I forgot to check in which forum I am posting my question. Sorry, I need now to remove the post from the C/C++ forum.
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Amr.Mohammad87 wrote: Sorry, I need now to remove the post from the C/C++ forum.
Can't be done now that your OP has been responded to. At best, it's content will be replaced with "message removed" and all replies will remain intact.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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My English is very pool,pardon me.This is my first time here.Today I come here to introduce a C++ program library which written by myself.This library called Covariant Graphics Library.This library can run on Linux,based on C++14 standard.If you have some questions about me and my library,just tell me.
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I don't know how to introduce my program because of my pool English.I'm just a normal senior high school student.
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The only way your library to become popular is to write an article that
describes the basic ideas as well as demonstrates the library usage.
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CSDNbuxingma?By the way,poor instead pool
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