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PIEBALDconsult wrote: So it still requires a test after each read?
It's a boolean flag, so yes.
PIEBALDconsult wrote: Can it rewind?
It's forward only - ref: PipeReader Class (System.IO.Pipelines) | Microsoft Learn[^]. You would need to close, reset stream position (if the stream supports it), then create a new reader.
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
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Yes, it would be more 'C#-style' if FileStream had methods byte FileStream.ReadByte() which throws an exception, and bool FileStream.TryReadByte(out byteVar), which returned true for success and false for failure. Bear in mind, however, that ReadByte() is a low-level API. I can think of many use cases where one just loops on the ReadByte() method until -1 is returned. Why burden the low-level reader with the overhead of a try/catch block, and possibly rethrowing a new exception wrapping the one thrown from the ReadByte() method?
High-level constructs are undoubtedly useful, but a 'good' language will also provide access to lower-level constructs, to be used with care.
EDIT: typo
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
modified 17-Aug-23 23:51pm.
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PIEBALDconsult wrote: I would much rather have FileStream.ReadByte() throw an Exception when it hits EOF.
Using exceptions for non-exceptional, totally expected situations, just to control program flow. 
If you really need to read a single byte at a time, then a TryReadByte method would be preferable:
public static bool TryReadByte(this Stream stream, out byte value)
{
int result = stream.ReadByte();
if (result == -1)
{
value = default;
return false;
}
value = (byte)result;
return true;
}
Otherwise, use Read(byte[], int, int) or Read(Span<byte>) and check how many bytes were read.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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PIEBALDconsult wrote: I would much rather have FileStream.ReadByte() throw an Exception when it hits EOF.
No, because exception handling is so much more costly than a simple check.
Also keep in mind that ReadByte internally does a check for Length == Position and returns -1 if they're equal. Reference Source[^]
So if you want to half the number of comparisons you should simply check for Length == Position before calling ReadByte.
<edit>Doh, doesn't half anything except when you have reached the eof.</edit>
But the question is rather, why don't you use Read() with a buffer instead? Uses one check for every Read().
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Jörgen Andersson wrote: exception handling is so much more costly than a simple check
Prove it -- and not with a debugger attached. I think a lot of the early complaints (twenty years ago) about .net Exception performance were because people were testing debug versions with the debugger attached, which seems to make Exceptions slow. But I have not seen any issues with Exception performance in real-life.
Jörgen Andersson wrote: use Read() with a buffer instead
Maybe, but then there would be two buffers, because the FileStream holds one (4096 bytes by default). I see no reason to duplicate the buffer when I can process only one byte at a time, there would be no IO performance benefit.
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You can't test "the performance of Exceptions" by simply throwing millions of them; that's not how they're used.
Experiment and test I will... eventually. I need to think more about what I don't like about FileStream:
-1 on EOF
No Peek
No Reverse (the Position can be set, but does that affect only the buffer?)
and what I want in a replacement for it.
Can I implement a "better" buffer than Microsoft? How smart or simple is the buffer in FileStream? How does it work?
The ability to Reverse is probably better implemented at a higher level, but it can be done at this level too.
I occasionally need to read sections of files in reverse and it would be good for it to perform better than it does -- as long as forward-reading performance isn't impacted. I recognize that it is not a common requirement.
Oddball said (Kelly's Heroes): You see, man, we like to feel we can get out of trouble, quicker than we got into it.
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Long ago certainly many OSes used a EOF marker at the end of files. It was a specific sequence of bytes. I can't speak to why in general that is no longer the case but I do know it was possible to maliciously overwrite that and thus the file would no longer have an end.
I would not be surprised however if the answer is related to buffers. Buffers exist all the way down the chain. Right down to the hardware.
And that means one can never 'read' to the end. Although some files would be an exact multiple of the buffer lengths most would not. So some other comparison must always be done.
Nothing stops you from replacing something in the current IO stream hierarchy. You probably can't replace the hardware buffering but I am rather certain that you can replace the IO libraries in the OS. Or inject something in to it. I think something like that happens with USB drives.
You can also replace libraries in your language of choice. This is not all that difficult in Java or in C++. I suspect it is more difficult with C# but I haven't looked.
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Yes, on MS-DOS there was char 26 (Ctrl-Z) which was an end-of-file marker in at least some cases.
Even in the past ten years I've had to deal with char 26 appearing in string values and causing trouble.
At most I would use P/Invoke to call the Windows API routines to read the file. And I would implement my own buffering system. Then add layers from there. But that's still just theoretical.
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Heavy Indian accent: "Hello, I am John from EE".
"No you're not, not coming in on that line."
*click*
I assume he thought I was a hacker and disconnected before I got to his servers. 
Of course, it helps that I've never been with EE ... and it's a whole load quieter than the air horn!
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!
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I don't have a land line anymore, only cell phone.
I just hang up on scam calls. If they call back, I block the number. I don't even speak to them.
I get very few tele marketing or scam calls these days.
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I never answer any calls that are from an unknown phone number.
If it is anything real they will leave a voice mail.
If it is real, I call the person back.
It is never real. Real people text me before they ever call me and I already have their phone number in my phone.
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Same here
In a closed society where everybody's guilty, the only crime is getting caught. In a world of thieves, the only final sin is stupidity. - Hunter S Thompson - RIP
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It depends on whether or not I'm looking for some entertainment.
I love when Windows support calls since I use a Mac. "Your computer has been sending us messages." Me, "Really? Which operating system does it say I have? What IP address does your system show for my machine? You called me, you should know these answers." Then I tell them I'm on a Mac. Usually get cursed at and then they hang up.
I love the "would you consider a cash offer on your house" calls too. I always say, "Yes, $100,000,000 firm." And revel in their stunned silence.
I’ve given up trying to be calm. However, I am open to feeling slightly less agitated.
I’m begging you for the benefit of everyone, don’t be STUPID.
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MarkTJohnson wrote: "Your computer has been sending us messages." Me, "Really? Which operating system does it say I have? What IP address does your system show for my machine? You called me, you should know these answers."
I always ask these guys how they managed to associate my IP address with my phone number.
Their script doesn't cover that. It always ends up with them disconnecting.
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If I receive one of those calls I act like I can't work a computer or say that I'm following their instructions and give random errors trying to drag it on as long as possible ... either way, they tend to lose their cool at the time wasted and hang up. Sometime I get abused. 
Graeme
"I fear not the man who has practiced ten thousand kicks one time, but I fear the man that has practiced one kick ten thousand times!" - Bruce Lee
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MarkTJohnson wrote: I always say, "Yes, $100,000,000 firm."
Hopefully in your best "Dr Evil" voice, with your finger crooked in the corner of your mouth? 
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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I once kept a "Windows Support" person on the line for a while, repeatedly asking which of my computers was the one that he was referring to. The best he could come up with was, "the one just near you".
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I've given the cash offer on my home the same answer.
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MarkTJohnson wrote: I love the "would you consider a cash offer on your house" calls too. I always say, "Yes, $100,000,000 firm."
Well that is amusing.
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As Robert Heinlein said "I always answer the phone, it may give me the opportunity to be rude to someone". As a retiree and being a grumpy old fart I welcome scammers.
Never underestimate the power of human stupidity -
RAH
I'm old. I know stuff - JSOP
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I tell scammer to go do anatomically impossible things to themselves. I had one with the gall to call me back to tell me I was being rude and I told her she's a f*ing scammer and that she initiated the call. Then I told her to contact the authorities if she didn't like my cussing at her and hung up.
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I am teaching basic arithmetic operations of integers - addition, subtraction, multiplication, division - to a middle school student. and am looking for innovative ways to teach these operations, in an easy-to-understand manner. Finding that the student at hand tends to repeat the mistakes, and is finding it difficult to learn; perhaps there's a basic fear instinct about mathematics in general.
How to get the child overcome such fear, and make him successful? Any ideas are welcome, am open to experimentation here. Thanks a lot.
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