get read_exact() read in bytes

especially with binary data if you hit the eof you cant check how many bytes you really read into the array

[sfackler]

read_exact is designed for the case when you know you need exactly N bytes. If you need more control you can build something that makes sense for your use case on top of read.

you cant predict when an eof will occur so you can check the buffer - this is only possible if the file contains only ascii chars
and for read() it returns 'some' bytes so you dont really know how many calls you need to fill the buffer. Another thing is the question does it read in blockwise? Otherwise it would be really slow.

[sfackler]

this is only possible if the file contains only ascii chars

What does ASCII have to do with anything here?

and for read() it returns 'some' bytes so you dont really know how many calls you need to fill the buffer.

Right - you loop over calls to read while you need more data.

Another thing is the question does it read in blockwise? Otherwise it would be really slow.

The implementation of read_exact is here: https://github.com/rust-lang/rust/blob/master/src/libstd/io/mod.rs#L701-L716

you cant iterate through an array of binary data as a 0 as value doesnt mean its the end of the file this is only applicable for text

[sfackler]

read copies data into the buffer and returns the number of bytes read. An end of file is indicated by returning zero. There is no number that is either zero or comes from the file.

[Centril]

triage ping @sfackler

[sfackler]

Pong?

[Centril]

@nifker at the moment we are unsure exactly what you are asking or want... can you clarify the issue with an example of what you are trying to solve or where your problem is?

@sfackler hmmm what abou the fucking array which is pribably longer than the read data? And you initialized it probably as 0 and im still talking about read_exact().
And what about if the file contains a binary 0?