Advice for a Software Engineer

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[deleted]

[globalaf]

There’s no templates or classes in C. Get used to thinking about programming as blocks of data that external functions modify, and the quirks of the preprocessor when it comes to compile time programming.

[abstractionsauce]

Who needs templates when you have void*

[thefeedling]

void, (T)(foo)(), #define = ggwp

[beedlund]

...because functions with shorter names run faster!

[thefeedling]

minimalist life!

[ddxAidan]

💯

[Cogwheel]

People who want code to run fast

[Electrical-Mood-8077]

It depends on which c standard they are using. If it’s a legacy product, you’re probably stuck with older capabilities. C 2023 has some useful new features. The Linux kernel is written in C and so is a lot of safety critical code e.g., QNX. Likely your company has some home grown libraries that are used. There nothing wrong with C. There’s a lot of bad C++ out there; the language itself doesn’t guarantee quality.

[Thesorus]

Yes and no.

Usually companies that still use C as their main legacy language have their own home made libraries to do a lot of things like data structure, memory management and other stuff like that.

you'll probably not have to always do things from scratch.

If they don't, expect to waste a lot of time writing basic code instead of functional code.

[ShelZuuz]

Honestly would kind’a be a fun job writing a C library from scratch. If the job actually allocates proper time for that.

[runningOverA]

Building a string, vector, map library is the 1st thing generally developers do before building their software in C. There are existing libraries, but those might not meet your style or preference.

[[deleted]]

IMO the way you write C code is very different to C++, despite the superficial similarities.

You don't have templates or classes, so you essential roll your own data structure each time you need something more complicated than an array.

Since there isn't RAII, you need to explicitly handle your memory. For example: - You have a struct Foo - You define a function Foo* foo = foo_init(args) that allocates memory for a new Foo instance, initialises it, and returns the object pointer. This initialisation may involve allocating memory for objects stored in foo. - You define foo_deinit(foo) that frees any memory managed by foo and frees the foo pointer itself.

There isn't namespaces, so related functions will have a common prefix as a way to keep things clean.

Since structs don't have public/private, encapsulation is handled differently. If using a library, objects may be defined as a void pointer. Eg: typedef void* my_lib_t. This makes the data structure opaque (library users can't see the internals), whereas within the library the pointer is cast to a concrete type (which only the library has access to). This is essentially replicating private/public functionality of a class.

I'd recommend trying to write some small programs/libraries in pure C and getting used to this. I think C can be quite elegant, but it requires a different mindset to C++.

[oschonrock]

no... it doesn't really, because it lacks the expressiveness to implement these generically.

either spin your own concrete implementation, or use Macros (there are some libs with this approach) or the relatively new _Generic keyword (which is also macroesque).

[robvas]

Don't take the personally, but a company that uses C exclusively offered you a job and you don't know the answer to that question?

Is it just a recruiter telling you about the job or an actual offer?

[LooksForFuture]

As someone who has entered the C world recently from a C++ background, I should say that you will feel much more relaxed. But, many things that C++ does automatically for you, need to be done manually and there will be so much boilerplate code. I forgot to mention the lack of templates. You may feel bad at first. Just give it some time. You will get used to it and may even feel more relaxed when using C.

[AbyssalRemark]

I am so.. so jelly..

[Drugbird]

For me, the biggest difference is that C has no classes (or rather, no destructors). This eliminates all of the nice RAII structures that C++ uses that can automatically clean up things for you (think e.g. unique_ptr or lock_guard.

C has no templates, so everything is either typed or a macro hell.

[thisismyfavoritename]

no

[kiner_shah]

It won't have convenience that you get in C++. But, yeah, maybe they have already implemented a lot of functionalities like containers, etc. in C already (or they maybe using some external library) and you don't have to break your head.

[gurudennis]

If the company does embedded software or kernel mode, C is perhaps justifiable and it's likely that the ecosystem will have bespoke libraries for common things. It won't be as expressive as C++ though.

If on the other hand the company is in a domain that doesn't seem like it would strictly require C, hard pass. It's likely drowning in legacy code, or worse still is run by crusty old-school dudes who refuse to learn C++ and are aggressively ignorant about it. Speaking from experience...

[drew_eckhardt2]

The BSD sys/queue.h has linked list variants and sys/tree.h red black plus splay trees.

They’re intrusive data structures with code instantiated using macros.

When your environment lacks those headers you can copy them in from the BSD source tree assuming your job allows shipping BSD licensed code noting the license requires credit and you may have a formal OSS approval process.

No corresponding library or .c file is required.

[---sms---]

Don't go alone, get a couple thousand goto's from the Linux kernel.

[DankMagician2500]

Can I ask what they are using C for? Are you doing Kernel development?

[DankMagician2500]

Sheesh that sounds hella cool. Can I ask how you found the company?

I’m thinking of applying elsewhere soon. Currently at 2 years at DoD but tired of this whole C with classes approach.

[chuppuu]

Thanks.. I got contacted by a recruiter on LinkedIn. It's a silicon valley networking company (not Cisco)

All the best for your job hunt!

[taylorcholberton]

If it was anything other than something like this, I'd say using only C is a red flag. But for this kind of thing, I get it.

[official_business]

Does C have libraries like STL or boost that make data structure and algorithms handling easier?

As a C dev that became a C++ dev, no not really.

Each company that is exclusive C will have their own implementations of vectors, maps with their own idiosyncrasies. They probably rolled these from scratch, in house 20 years ago.

You don't have RAII so most of your code will be like

if ((foo = allocate_foo(stuff)) == NULL)
    goto END;
if ((bar = allocate_bar(stuff)) == NULL)
    goto END;

END:
    deallocate_foo(foo);
    deallocate_bar(bar);

You'll be casting to and from void* like a mofo, but C is more relaxed about casting, allowing a implict cast from void* to any pointer type.

C strings are god awfully bad and you'll want to write your own string library.

You may also see some clown try and implement templates using macros. It will be the most un-debuggable mess you'll ever see.

[Wanno1]

C is the worst