Hi,
I need to write out bits that I receive from another process. These
are boolean values. I need there to be 8 bits in every byte. I know I
could write these bits out as char's using one bit per byte, but that
would be space-inefficient.
I'm using od (octal dump) to look at a file produced by calling
..Write(true) and .Write(false) and it looks like it writes out 4 bytes
per boolean value.
What am I missing? In what world does it take 4 bytes to represent a
boolean value? Is there some sort of alignment issue that's causing
this?
THANKS!!!!
John 9 4643
John <jo********@hot mail.com> wrote: I need to write out bits that I receive from another process. These are boolean values. I need there to be 8 bits in every byte. I know I could write these bits out as char's using one bit per byte, but that would be space-inefficient.
I'm using od (octal dump) to look at a file produced by calling .Write(true) and .Write(false) and it looks like it writes out 4 bytes per boolean value.
What am I missing? In what world does it take 4 bytes to represent a boolean value? Is there some sort of alignment issue that's causing this?
StreamWriters are for *text* data, not binary data, which is what it
sounds like you want.
StreamWriter.Wr ite(bool) writes out the *text* representation of a
boolean, as documented.
--
Jon Skeet - <sk***@pobox.co m> http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Takes 4 bytes since that is the memory layout of a bool. Based on the way
the streams work, the best they could do is 1 byte per bool if you used
Write(bool) Read(bool). However, you could do better by having a set of
methods that took an array of bools and converted that into a series of bytes
depending on how many bools you were emitting.
--
Justin Rogers
DigiTec Web Consultants, LLC.
Blog: http://weblogs.asp.net/justin_rogers
"John" <jo********@hot mail.com> wrote in message
news:d8******** *************** ***@posting.goo gle.com... Hi,
I need to write out bits that I receive from another process. These are boolean values. I need there to be 8 bits in every byte. I know I could write these bits out as char's using one bit per byte, but that would be space-inefficient.
I'm using od (octal dump) to look at a file produced by calling .Write(true) and .Write(false) and it looks like it writes out 4 bytes per boolean value.
What am I missing? In what world does it take 4 bytes to represent a boolean value? Is there some sort of alignment issue that's causing this?
THANKS!!!!
John
Justin Rogers <Ju****@games4d otnet.com> wrote: Takes 4 bytes since that is the memory layout of a bool.
Nope, it takes 4 bytes since it's writing out "True" - it would take 5
bytes if you passed in false (assuming an encoding which uses one byte
per character, of course).
--
Jon Skeet - <sk***@pobox.co m> http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Hi John.
You better use FileStream.Writ eByte to do this.
Cheers,
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
"John" <jo********@hot mail.com> wrote in message
news:d8******** *************** ***@posting.goo gle.com... Hi,
I need to write out bits that I receive from another process. These are boolean values. I need there to be 8 bits in every byte. I know I could write these bits out as char's using one bit per byte, but that would be space-inefficient.
I'm using od (octal dump) to look at a file produced by calling .Write(true) and .Write(false) and it looks like it writes out 4 bytes per boolean value.
What am I missing? In what world does it take 4 bytes to represent a boolean value? Is there some sort of alignment issue that's causing this?
THANKS!!!!
John
There is no API in .net (or C++ or Java or almost anywhere) that lets you
write a single bit. The smallest unit you can manipulate in a file is a
byte. (Ever seen a file that's got a size of 9 bits?)
If you want to save space, you may use helpers like BitVector32 or BitArray
for the bit-byte conversions.
Niki
"John" <jo********@hot mail.com> wrote in
news:d8******** *************** ***@posting.goo gle.com... Hi,
I need to write out bits that I receive from another process. These are boolean values. I need there to be 8 bits in every byte. I know I could write these bits out as char's using one bit per byte, but that would be space-inefficient.
I'm using od (octal dump) to look at a file produced by calling .Write(true) and .Write(false) and it looks like it writes out 4 bytes per boolean value.
What am I missing? In what world does it take 4 bytes to represent a boolean value? Is there some sort of alignment issue that's causing this?
THANKS!!!!
John
You'll not squeeze a ninth in there sunshine no matter how hard you pack it.
No-one's managed it yet, so I doubt you will.
Doh! You're right. I meant to say BinaryWriter.
I ended up writing a method that packs the bits into bytes and then
writes the bytes out.
I'll investigate BitArray and see how it might be helpful.
Thank you to all for your help!
John
Jon Skeet [C# MVP] <sk***@pobox.co m> wrote in message news:<MP******* *************** **@msnews.micro soft.com>... John <jo********@hot mail.com> wrote: I need to write out bits that I receive from another process. These are boolean values. I need there to be 8 bits in every byte. I know I could write these bits out as char's using one bit per byte, but that would be space-inefficient.
I'm using od (octal dump) to look at a file produced by calling .Write(true) and .Write(false) and it looks like it writes out 4 bytes per boolean value.
What am I missing? In what world does it take 4 bytes to represent a boolean value? Is there some sort of alignment issue that's causing this?
StreamWriters are for *text* data, not binary data, which is what it sounds like you want.
StreamWriter.Wr ite(bool) writes out the *text* representation of a boolean, as documented.
John <jo********@hot mail.com> wrote: Doh! You're right. I meant to say BinaryWriter.
Well BinaryWriter only writes out a single byte when you call
BinaryWriter.Wr ite(bool). If you believe you have an example where you
believe it writes four bytes, please post it.
I ended up writing a method that packs the bits into bytes and then writes the bytes out.
Right.
--
Jon Skeet - <sk***@pobox.co m> http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jon Skeet [C# MVP] <sk***@pobox.co m> wrote in message news:<MP******* *************** **@msnews.micro soft.com>... John <jo********@hot mail.com> wrote: Doh! You're right. I meant to say BinaryWriter.
Well BinaryWriter only writes out a single byte when you call BinaryWriter.Wr ite(bool). If you believe you have an example where you believe it writes four bytes, please post it.
Again, you're right. I started with StreamWriter. Then I realized I
should be using BinaryWriter. I ended up writing a method that packs the bits into bytes and then writes the bytes out.
Right.
Thanks for your help! Thanks for your patience!
John This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: Sowen |
last post by:
Hi, all
I am wondering how to write bits by using ofstream?
I have finished a huffman tree, but how can I write the bits to the file in
order to gain compression?
for example, 'A' returns a code '1101', what I should write? 13? no, I don't
think so
|
by: Lauren Quantrell |
last post by:
I'd like to use my Access 2K application to write some text in the
file properties of a Windows file. The properties I'm talking about
are the properties you see whn you right click on a Windows file and
then click on Properites, then the Summary tab.
I want to be able to modify the Subject line and the Comments line in
particular.
I'm hoping someone can tell me how to do this.
Thanks,
lq
|
by: ben beroukhim |
last post by:
I have huge number of legacy code which use standard files functions.
I would like to pass a memory pointer rather than a FILE pointer.
I am trying to use FILEs in the code to refer to memory buffers.
Basically, I want to be able to use all the standard read and write
functions, but I want them to refer to memory locations, rather than
disk
files.
I do not want to touch the legacy code. Does any one know of a library
|
by: shefali |
last post by:
Hi,
I need to use an HTTPHandler to create and write files. I wanted to create
the file in the directory that has this handler, and other handlers. For me,
this directory is: c:\Inetpub\wwwroot\HttpHandlers. I get an error: "Access
to the path "C:\Inetpub\wwwroot\HTTPHandlers\bidhero.ccn" is denied."
I can have the code write files to other locations just fine. I'm using
ASP.net v.1.1 on Windows XP, and Windows 2003.
|
by: Leon |
last post by:
Can you write over a value in session or do you have to delete the value
first then re-create it?
**Example:
I have the following value in session state...
Statement 1 -- Session.Add("Email", "someone@ someplace.com ")
And I want to change it to the following value...
Statement 2 -- Session.Add("Email", "someone@ msn.com ")
| |
by: Kevin |
last post by:
I'm writing a service in VB.NET. Reference the following code:
Dim oStreamWriter As StreamWriter
....
....
....
oStreamWriter = File.CreateText(TempLogFile)
If Err.Number <> 0 Then
EventLog.WriteEntry("LogService", "Error Creating Log File: " & _
TempLogFile & vbCrLf & _
|
by: HareshKarkar |
last post by:
Hi ,
I'm calling some Javascript function to write value in the layer. I'm trying to achieve it by using eval() function. Please look at the code below:
function showMore(tempLayerNum, tempLayerName) {
var temp = "step"+tempLayerNum+"More".toString();
eval(temp).write("Hi");
}
|
by: Swan |
last post by:
Can anyone plz tell me,Can I write file on server using binary access,or it is only to write on local?(Actually I am creating OCX for Http File Upload Control in VB using API's.So for that I need to raed file from local and write it to server.)
Thanking you!
|
by: Monica Leko |
last post by:
Hi
I have a specific format and I need binary representation. Does
Python have some built-in function which will, for instance, represent
number 15 in exactly 10 bits?
|
by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
| |
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
|
by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules.
He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms.
Adolph will...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
|
by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
|
by: adsilva |
last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
|
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
| |
by: bsmnconsultancy |
last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...
| |