C / C++ / MFC Discussion Boards

Re: What is the size of an integer?

sunit527-Dec-05 22:57

sunit5

27-Dec-05 22:57

size of int is OS dependent

never say die

Re: What is the size of an integer?

Zdeslav Vojkovic27-Dec-05 23:37

Zdeslav Vojkovic

27-Dec-05 23:37

actually, it is not OS dependent, but implementation dependent. standard states that sizeof(int) >= sizeof(short), and short is at least 16 bits. so, for different compilers, sizeof(int) can be different even on the same OS.

Re: What is the size of an integer?

Prakash Nadar27-Dec-05 23:59

Prakash Nadar

27-Dec-05 23:59

and they are also processor dependent but not too much though.

<hr<span style="color:gray;size:15px;">-Prakash
-Prakash

Re: What is the size of an integer?

vikas amin28-Dec-05 0:03

vikas amin

28-Dec-05 0:03

Processor dependent ?????
Confused | :confused:

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: What is the size of an integer?

Prakash Nadar28-Dec-05 0:09

Prakash Nadar

28-Dec-05 0:09

Well to understand this u need to know how softwares are dependent on hardware (processor)

generally the integer size is the size of word size of the processor, for 80386 onwards the word size is 32 bit and hence the integer size in most of the OS on Intel machine is 32bit.

Why the size of integer varies from compiler to compiler/OS 2 OS, because integer is the most used datatype and transfering a 32bit of data from the memory to processor is more efficient than other sized data.

<hr<span style="color:gray;size:15px;">-Prakash
-Prakash

Re: What is the size of an integer?

ThatsAlok28-Dec-05 0:51

ThatsAlok

28-Dec-05 0:51

vikas amin wrote:
Processor dependent ?????

In continuation with Mr. Prakash.. if you see := sizeof(long)==sizeof(int) in windows enviornment

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

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Re: What is the size of an integer?

David Crow28-Dec-05 5:48

David Crow

28-Dec-05 5:48

Zdeslav Vojkovic wrote:
...sizeof(int) can be different even on the same OS.

Do you have a valid example of such? I've never seen an int that varied in size on the same machine.

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: What is the size of an integer?

Gary R. Wheeler28-Dec-05 6:09

Gary R. Wheeler

28-Dec-05 6:09

This goes back a bit in time, but...

In Microsoft C 6.0 (MS-DOS era), an int was 16 bits. Watcom C 9.0, on the same machine, made an int to be 32 bits. The Microsoft target in this case was 16-bit real-mode MS-DOS while the Watcom target was 32-bit protected mode MS-DOS.

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Re: What is the size of an integer?

David Crow28-Dec-05 6:12

David Crow

28-Dec-05 6:12

But was it a true 32-bit int? That's like saying we have a 64-bit int today, but only because Microsoft's compiler mashes two 32-bit ints together, simulating a bigger one.

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: What is the size of an integer?

Gary R. Wheeler28-Dec-05 6:51

Gary R. Wheeler

28-Dec-05 6:51

Actually it was. The 80386 processors and their descendents included direct 32-bit arithmetic and pointer support. The Watcom compiler supported protected mode execution with a flat memory model for a variety of DOS extenders. A "DOS extender" basically provided an execution environment for a protected mode application in the MS-DOS environment.

DavidCrow wrote:
Microsoft's compiler mashes two 32-bit ints together

Hmm. Is that still the case? I was under the impression that __int64 support since VS.NET 2002 was provided directly by native instructions.

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Re: What is the size of an integer?

David Crow28-Dec-05 7:49

David Crow

28-Dec-05 7:49

Gary R. Wheeler wrote:
Is that still the case?

I'm not sure since I only use VC++ v6.

Gary R. Wheeler wrote:
I was under the impression that __int64 support since VS.NET 2002 was provided directly by native instructions.

Even on processors that do not a have 64-bit bus?

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: What is the size of an integer?

vikas amin28-Dec-05 0:50

vikas amin

28-Dec-05 0:50

Probably i would preffer to say
implementation dependent then
processor dependent .
Cool | :cool:

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: What is the size of an integer?

Prakash Nadar28-Dec-05 5:33

Prakash Nadar

28-Dec-05 5:33

vikas amin wrote:
Probably i would preffer to say
implementation dependent then
processor dependent .

yes but the implementation is dependent on the processor. Smile | :)

-Prakash

Re: What is the size of an integer?

segment_fault3-Jan-06 17:51

segment_fault

3-Jan-06 17:51

The most important thing to do is to always use the "sizeof" operation in any code you're referring to. Never, ever hardcode the size into your code. When reading/writing to a file - there are exceptions -- in general, avoid using "int" as a type when it comes to storage of data structures. Instead, define types such as DWORD, WORD, BYTE, etc. This will save you a lot of trouble down the road.

Read more of what I have to say at http://directx9.blogspot.com/

Re: What is the size of an integer?

Prakash Nadar3-Jan-06 19:12

Prakash Nadar

3-Jan-06 19:12

segment_fault wrote:
The most important thing to do is to always use the "sizeof" operation in any code you're referring to. Never, ever hardcode the size into your code. When reading/writing to a file - there are exceptions -- in general, avoid using "int" as a type when it comes to storage of data structures. Instead, define types such as DWORD, WORD, BYTE, etc. This will save you a lot of trouble down the road.

yes i know that.

-Prakash

How to receive a very large data via Serial COM Port ?

QuangDien27-Dec-05 20:44

QuangDien

27-Dec-05 20:44

Hi everybody,

I have a sensor to capture the fingerprint image and then send to PC via Serial COM Port. And I use MSCOMM Control 6.0 for transfering & receiving data in Serial COM Port. Here below is the structure of the data which the sensor send to me :

HEADER : 6 bytes
DATA : Fingerprint Image 280 x 240 = 67200 bytes !!!
FOOTER : 4 bytes

But the buffer of MSCOMM Control is only 32768 ( = 2^15 ). Therefore, now my problem is the size of that image is too large to receive in buffer. The buffer is overflow !!! In this situation, I think there are 3 ways to solve it :

+ Incearse the size of the MSCOMM's buffer.
+ Use other class for transfering & receiving data in Serial COM Port with the buffer enough large.
+ Parallel processing : doing both receiving data from sensor and saving data from buffer to other place ... simultaneously.

But I don't know how to implement above methods !!! Please kindly help me or you can show me other solutions ... THIS IS MY FINAL PROJECT FOR GRADUATING MY UNIVERSITY and the deadline is coming nearly, so, again, please help me !!!
Thank you very much !!!
Best regards,

Quang Dien
Email to me : quangdien12jan@yahoo.com

Re: How to receive a very large data via Serial COM Port ?

Gary R. Wheeler28-Dec-05 6:40

Gary R. Wheeler

28-Dec-05 6:40

Did you try searching Code Project[^]?

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Problem in using TCHAR

G Haranadh27-Dec-05 20:23

G Haranadh

27-Dec-05 20:23

I could not get what is the wrong in this?
Please let me know.
I am getting the error as follows.
error C3861: 'sprintf': identifier not found, even with argument-dependent lookup

TCHAR str1[50]=_T("");//(Or)//CHAR *str1=_T("");
_stprintf(str1,_T("The Sum is %d"),Add(10,20));
MessageBox(NULL,str1,_T("Add"),NULL);

Here I Like to use _stprintf. How to use it?

Nice talking to you. Blush | :O

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Re: Problem in using TCHAR

Owner drawn27-Dec-05 20:44

Owner drawn

27-Dec-05 20:44

G Haranadh wrote:
_stprintf(str1,_T("The Sum is %d"),Add(10,20));

Try this...

_stprintf(str1,L"The Sum is %d",Add(10,20));

Hope this works Unsure | :~

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Re: Problem in using TCHAR

G Haranadh27-Dec-05 20:53

G Haranadh

27-Dec-05 20:53

: error C3861: 'sprintf': identifier not found, even with argument-dependent lookup
: error C3861: 'L': identifier not found, even with argument-dependent lookup

Sorry. it gave two errors. Unsure | :~

Nice talking to you. Blush | :O

If you judge people, you have no time to love them. -- Mother Teresa

Re: Problem in using TCHAR

Owner drawn27-Dec-05 21:01

Owner drawn

27-Dec-05 21:01

lol

It is working fine here. Not the one I suggested but the one you gave

TCHAR str1[50]=_T("");//(Or)//CHAR *str1=_T("");
_stprintf(str1,_T("The Sum is %d"),Add(10,20));
MessageBox(NULL,str1,_T("Add"),NULL);

Jesus Loves You and Me Smile | :)

Re: Problem in using TCHAR

sunit527-Dec-05 22:50

sunit5

27-Dec-05 22:50

_stprintf(str1,L"The Sum is %d",Add(10,20));

use swprintf instead of _stprintf if u r using L"The Sum is%d"

Re: Problem in using TCHAR

Prakash Nadar27-Dec-05 21:24

Prakash Nadar

27-Dec-05 21:24

Hope you included stdio.h header file.

and plus try using stprintf instead of _stprintf

<hr<span style="color:gray;size:15px;">-Prakash
-Prakash

-- modified at 11:39 Wednesday 28th December, 2005

Re: Problem in using TCHAR

vikas amin27-Dec-05 22:48

vikas amin

27-Dec-05 22:48

did u include <stdio.h>

have u tried this

char *str1="";
sprintf(str1,"The Sum is %d",Add(10,20));

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: Problem in using TCHAR

sunit527-Dec-05 22:52

sunit5

27-Dec-05 22:52

I feel it wont work

char *str1="" is equivalent to const char *str

that means we cannot change the content of the address stored in str

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