hi everybody..
It's my first post in this forum, and I'm wonder -just an curiosity, why I see much more code in C than in C++
under linux..
If C++ got classes and all that 'advantages'.. why it isn't so used like C ?
regards.

the linux kernel is writen in c for starters.

Slightly off-topic, but anyway...

If a project as large and complex as the Linux kernel can be implemented as successfully as it has been in C, it makes me wonder if there's any real merit in coding in C++ in the first place. After all, the whole point of coding in an Object Orientated style is to make large, complex projects manageable.

Just a thought.

On the other hand, I know Not Much At All about kernel hacking, so maybe writing operating systems doesn't lend itself to OO programming.

It should be noted that I learned to program in Ada and Java, so I'm in no way a Procedural Language zealot, and I generally prefer programming in terms of objects.

Dave

There are several reasons:

• The advantages of c++ are smaller than you think. See the c++ chapter of "The Art of Unix Programming" for discussion about this.
• Other languages (perl, java, python, PHP) have more advantages so they are used instead of c++.
• Quality of the gcc c++ compiler used to be much worse than the c compiler. This probably isn't the case anymore, but many old projects use C because of it.
• Writing portable c++ code is hard because every compiler (including different versions of gcc) supports different version of the language standard and different set of features.

Open source developers like to modularize their projects at higher level, splitting a complex project to multiple sub-projects. For example, in the Linux kernel each driver is a sub-project. This reduces complexity the same way as using OO.

very thanks 4 the answers
Harmaa: very interesting link .. I'm reading more than that article from such book.
fell now I know a little bit more..

C++ is slower and produces larger binaries than straight C. I demonstrated this in another thread in this forum.

For system-level programming, C just makes more sense. It provides better access to the hardware and so forth.

Also, C is much more standardized and contains fewer extensions that are platform-dependent than C++.

On the flip side, C++ does have some nice toys for quick-and-dirty work. And C++ classes CAN be useful.

GNOME is written in C, KDE uses C++. GNOME is considering to adopt a higher-level language for their project though.

IMHO C++ makes more sense for complex desktop applications, allowing programmers to think about more complex situations instead of worrying about low-level stuff. Background processes (think apache, sshd) perform many low-level tasks, C is a nice choice. For desktop appliations, problems like "how can I make two parts of my problem interact nicely?" arrise. C++ gives an answer for this. In effect, many users are able to create new kde applications, building on the development platform created by KDE.

KDE did suffer from the bad performance of C++ in the past, but they've also tracked the problems down to issues with GNU "ld" and "gcc". Improving the GNU stuff would fix many "C++ is slow" issues too. (gcc-3.4 already gives KDE more performance)