if i make a program in C or C++, will it work on Linux and Mac?

Yes, if it's source compatible.

If it's compiled on the platform that you want to use it on most times since the implementation of the C runtimes vary from OS to OS see if you make a graphical C++ program under Windows you would have to use Linux to run it but for the most part if you use the standard libraries I believe you should be fine

[quote author=Warrior link=topic=10960.msg104510#msg104510 date=1111238429]
if you make a graphical C++ program under Windows you would have to use Linux to run it
[/quote]

...errr?

For cross-platform GUI support, I highly recommend wxWidgets.

It likely won't, unless you spend a lot of time trying to make it cross platform.

There are many toolkits like gtk, wxWidgets, etc. to help you.

Also, you should look into autoconf and automake which are standard tools for generating Makefiles which help you compile your code properly on every platform.

Also, command line programs are easy to make portable, very much easier than GUI.

You should probably try porting it to Java, which wouldn't be too hard because their both Carbon variants. Since java code is run through an executable itself, java.exe for Windows, a single "executable" .class file is usable under Windows, MacOS X, *nix, and any other platform the Java RE runs on.

[quote author=Joey link=topic=10960.msg104569#msg104569 date=1111272754]
You should probably try porting it to Java, which wouldn't be too hard because their both Carbon variants. Since java code is run through an executable itself, java.exe for Windows, a single "executable" .class file is usable under Windows, MacOS X, *nix, and any other platform the Java RE runs on.
[/quote]

He doesn't want to use an incomplete language like Java.  :)

lol hahahahaha. i dunno how to code in C++. i just wanted to know if it was possible.