/dev/chat

Kusalananda

06:39

@JohnnyApplesauce This will probably depend on the specific filesystem in use. The standard stat() function returns the size of the file in number of blocks. The block count has the type blkcnt_t (a signed integer type, but not specified closer than that by POSIX).

@santimirandarp duckduckgo.com/…

Stephen Kitt

07:44

@Kusalananda st_size in struct stat measures a file’s size in bytes, and that’s what stat() gives... The type is off_t which is a “signed integer type”.

Kusalananda

07:56

@StephenKitt Too early in the morning. But, hmmm.... Which of the block and byte counts is the one stored on disk? Probably both?

Stephen Kitt

@Kusalananda You always need the byte count in some fashion, the specifics presumably vary depending on the file system — it could be blocks + bytes used in the last block... Using block counts might result in “interesting” handling with sparse files, so I suspect most file systems store the apparent file size explicitly.

Kusalananda

08:37

@StephenKitt Thanks. So in any case, returning to @JohnnyApplesauce, it depends on the filesystem.

Stephen Kitt

@Kusalananda and the size of int ;-)

Isaac

@StephenKitt Well, the size given in each filesystem must be static, as disks may move between OSes (or booted with different OSes). So, for example, for ext [linux](https://www.nongnu.org/ext2-doc/ext2.html#i-size) is either 32 bit or 64 bit.

i_size

In revision 0, (signed) 32bit value indicating the size of the file in bytes. In revision 1 and later revisions, and only for regular files, this represents the lower 32-bit of the file size; the upper 32-bit is located in the i_dir_acl.

Stephen Kitt

@Isaac I’m not sure I understand what you’re getting at...

I was alluding to the fact that JohnnyApplesauce asked whether the size was an int or a long; the answer to that depends on the size of an int on the given system.

(As an interface concern, not the value stored on the file system.)

Isaac

08:57

@StephenKitt Yes, answering in terms of ints and/or longs it depends on the OS. But a disk already formatted has some data already written that is independent of the OS that is used to read it. In ext4 it is 64 bit. Whether that is an int, long, or double I'll pass.

Stephen Kitt

@Isaac of course. I was cracking a joke based on a literal take of JohnnyApplesauce’s question.

@Isaac BTW the reference for Ext4 internals is kernel.org/doc/html/latest/filesystems/ext4/index.html

Isaac

09:31

@StephenKitt Yes, depending on who you ask you may get (slightly) different answers :-)
However, still in both, i_size_lo and i_dir_acl each store 32 bit of the size value (taken from this kernel page https://www.kernel.org/doc/html/latest/filesystems/ext4/dynamic.html#inode-size

I find the gnu page simpler, easier to read for general reference.

Stephen Kitt

@Isaac yes, I know what’s stored on disk

Isaac

@StephenKitt Ooops, sorry if I disturbed you, no intent of that whatsoever. Be happy :-)

Stephen Kitt

@Isaac no worries, be happy too!

Tim

12:10

I used R quite a while ago, without much understanding of the language

R is a very different language to me. I am looking at its connection with other languages

Happy Wednesday, chat

Meanwhile not sure about the employability of R though

Faheem Mitha

@Tim R is a sucky language, but it's very widely used.

Though since it's essentially a statistical environment, it's not so useful unless you are planning to do statistics.

Tim

From Advanced R, 2ed, 2019 by Wickman

> Because the R community mostly consists of data scientists, not computer sci-
entists, there are relatively few books that go deep in the technical underpin-
nings of R. In my personal journey to understand R, I’ve found it particularly
helpful to use resources from other programming languages. R has aspects of
both functional and object-oriented (OO) programming languages. Learning
how these concepts are expressed in R will help you leverage your existing

> knowledge of other programming languages, and will help you identify areas
where you can improve.

> To understand why R’s object systems work the way they do, I found The
Structure and Interpretation of Computer Programs 1 [Abelson et al., 1996]
(SICP) to be particularly helpful. It’s a concise but deep book, and after read-
ing it, I felt for the fi rst time that I could actually design my own object-
oriented system. The book was my fi rst introduction to the encapsulated
paradigm of object-oriented programming found in R, and it helped me un-
derstand the strengths and weaknesses of this system. SICP also teaches the

In the past, I glanced the three books he recommended but they didn't feel the way the author described.

What books or materials do you guys recommend?

I am reading about its FP and OO parts currently, because some problem that I have to solve interrupt my study of cluster managers and distributed file systems

Faheem Mitha

12:30

@Tim Recommend for what? And if you are trying to learn R, why?

It's not exactly recreational activity. People typicall learn/use R because they want to do things like data analysis.

Not for cultural reasons. It's a crappy language, and is something of a mess from a syntax POV.

Even one of the co-authors admitted as much.

Co-creators, sorry.

terdon

13:11

Unfortunately, it is now incredibly popular in bioinformatics.

Jeff Schaller

13:26

Unfortunately, bioinformatics is now incredibly popular

Tim

Recommendations on materials about R?
Employability of R besides bioinfomatics?

Disclaimer: I don't have bias against or towards working in bioinfomatics. I know it is ivory tower

terdon

@JeffSchaller Well, that one I can live with ;)

JohnnyApplesauce

14:22

What is up with the meme of languages (like R, Python, and JS) that try to allow both functional programming and object-orientation?

Jeff Schaller

Fortunately, the charging one has been solved now that we've all standardized on mini-USB. Or is it micro-USB? Shit.

Faheem Mitha

15:18

@terdon Bioconductor. I know.

@Tim I suspect it's not possible to study everything. At least in real life, as opposed, to, say the Marvel Universe.

I'd pick something you're actually interested in, and work on that.

Stress levels rising here. Some days, I wish I drank. I hear it numbs the mind.

Tim

I am never lucky enough to stay in a field to thrive.

If I were, I would probably also chatting about days of lives and posting memes

terdon

15:58

@JohnnyApplesauce Most do, don't they? I mean, if a language has OO tools, that doesn't mean you can't do functional programming, right?

Anyway, I think most of those (except JS) predate the OO idea, don't they? So the OO stuff was added later. I know that was the case for Perl.

Faheem Mitha

I believe Smalltalk had an early OO implementation. Though Common Lisp might have been earlier.

Stephen Kitt

the first OO language was Simula in the 1960s, and Smalltalk followed a few years later

CLOS came after that

Faheem Mitha

16:21

@StephenKitt Ok.

terdon

16:51

@StephenKitt Well, so much for my chances of appearing knowledgeable about programming language history then. OK, but it is true that python and perl had their OO tools sort of pasted on after the fact, right?

Stephen Kitt

@terdon dunno about Python, but Perl did, yes

terdon

A developer I met once went off on a long rant about how python is not actually an OO language but only has some features that let it mimic it. This was observed by another developer I know who has ~40 years experience or so and he seemed to agree.

Sadly, most of it went way over my head, but they seemed to know what they were talking about.

Kusalananda