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C for high level programmers (slides)

charliethe.ninja

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Re: C for high level programmers (slides)

#31

Post by caf »

chrixian wrote: post #16

The thing about pointers that I don't get is why do you need the memory address of the variable? Is that the only way to get the value when you want it? Like, every variable has to have a pointer in order to make use of the variable?

You don't need the address of a variable: you can use the plain variable just fine, and most C code does a lot of that.

What a pointer does is add a level of indirection: so instead of having a value "an integer" you can have a value which is "the location of an integer". A variable holding such a value can be assigned the location of any integer variable, and importantly can also be reassigned the location of a different integer variable.

The additional indirection also means that you can link one data structure to another without including one as an integral part of the other.

Re: C for high level programmers (slides)

#33

Post by kibibu »

TheAceOfHearts wrote: post #27

I think the problem with learning C is that you need to learn stuff like make, autoconf, how the compiler + preprocessors work (what do all those flags even mean!?), how making "cross-platform" stuff works, how to pull in and use "libraries", C-isms, how to test, etc. C itself is a very small and simple language, but the tooling and patterns are old and mysterious. In college I learned how to program embedded systems…

Javascript has the same problem, but I think its worse. At least there are platform standards in C (autotools in GNU, msbuild on Win).

Trying to figure out how Grunt/Gulp/Broccoli, LESS/SASS/Stylus/Jade, Coffeescript, Uglify, Bower, Browserify, Require.js, AMD/CommonJS, NPM etc all work together is a nightmare.

It's all too hard, so people added Yeoman, Brunch, or other things to generate application configs - but now you need to decide which skeleton/generator you want, which takes you down the JS and CSS framework rabbithole.

Of course the only sane response to all this is to write another build system that doesn't repeat everybody else's mistakes.

In comparison, Makefiles are remarkably usable.

Re: C for high level programmers (slides)

#34

Post by caf »

charlesL wrote: post #14
akkartik wrote: post #13

No mention of undefined behavior? That's the first thing I tell people about C, considering how easy it is to trigger.

The issue with undefined behavior is it's kind of hard to... well... define. It's an odd combination of unsafe memory, float/integer rollover, and rules with memory allocation. I wasn't quite sure how to clearly state it.

All you really need to say is: There are some rules in C which neither the compiler nor the runtime is required to check if you've broken. On the contrary, the implementation is allowed to assume that you haven't broken them - which means that if you do break these rules, all bets are off as far as the behaviour of your program goes, which may lead to all sorts of strange and apparently inconsistent results.

Re: C for high level programmers (slides)

#35

Post by allcentury »

As someone who just reread "C Programming Language", in chapter 1 they teach you how to count occurrences of characters so I'm not sure I understand the sarcastic tone of "you're not going to count foo in a file". C can be used for many things, I don't think the author of the slides dod a great job of describing "when" C is the right tool for the job.

Re: C for high level programmers (slides)

#36

Post by thelogos »

TheAceOfHearts wrote: post #27

I think the problem with learning C is that you need to learn stuff like make, autoconf, how the compiler + preprocessors work (what do all those flags even mean!?), how making "cross-platform" stuff works, how to pull in and use "libraries", C-isms, how to test, etc. C itself is a very small and simple language, but the tooling and patterns are old and mysterious. In college I learned how to program embedded systems…

Personally, the hardest part for me was keeping track of the size of everything. Coming from a higher level language, keeping track of the bits and bytes takes some getting used to. Working with arrays in C is much tougher especially when the compiler will compile almost anything you give it, and even a small mistake is catastrophic.

Before C, I was pampered and took everything for granted. Now I appreciated my life more after C and feel blessed every time my IDE gives me a warning.

Re: C for high level programmers (slides)

#37

Post by pkulak »

I was hoping this would actually tell me how to accomplish something in C. I know all about pointers and memory, but I don't know anything about the current state if C development. What libraries do people use? What are common memory management strategies? Etc.

Re: C for high level programmers (slides)

#38

Post by saadel »

charlesL wrote: post #7
joshuapants wrote: post #4

I just about died laughing at slide 22. Anybody know how these slides were made?

Hey author of the slides here, glad you liked it :D I used http://remarkjs.com/ to make the slides. All you have to do is include the script, add a textfield with your content in markdown and it automatically converts to a slide show.

Can you tell us what font you used?

Re: C for high level programmers (slides)

#39

Post by userbinator »

TheAceOfHearts wrote: post #27

I think the problem with learning C is that you need to learn stuff like make, autoconf, how the compiler + preprocessors work (what do all those flags even mean!?), how making "cross-platform" stuff works, how to pull in and use "libraries", C-isms, how to test, etc. C itself is a very small and simple language, but the tooling and patterns are old and mysterious. In college I learned how to program embedded systems…

I don't think you need to learn the build system until after you're comfortable with single-file programs, where "gcc yourfile.c" is enough. Then add compiler options, and get to know Makefiles after your programs grow large enough to require multiple files.

GNU coreutils (and in general, a lot of the GNU projects) are rather excessively complex and certainly not what I'd advocate "learning by example" from. Take a look at the BSDs' standard utilities for simpler, more straightforward code.

But even if I can eventually understand what some code does, how do I learn why it does it that way?

I believe that the best way to learn "why" is to ask "why not". You will see that a lot of programmers, IMHO unfortunately really don't know why and are just doing what they were taught to. If you don't do X, then either [1] it doesn't matter and you don't actually need to, or [2] it does and you realise the reason why, when you see how X makes things simpler/more efficient for either the programmer or the machine, or both.

Re: C for high level programmers (slides)

#40

Post by rhodysurf »

TheAceOfHearts wrote: post #27

I think the problem with learning C is that you need to learn stuff like make, autoconf, how the compiler + preprocessors work (what do all those flags even mean!?), how making "cross-platform" stuff works, how to pull in and use "libraries", C-isms, how to test, etc. C itself is a very small and simple language, but the tooling and patterns are old and mysterious. In college I learned how to program embedded systems…

I switched to CMake for all of my C and C++ projects and i never looked back. Takes care of a bunch of makefile issues for you once you get used to it.
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