UNIX for Dummies Questions & Answers

Dear all, I have downloaded the latest version of gcc --- gcc-3.3.1.tar.gz from gnu.org. My Linux distribution is Mandrake 9.0. This was how I installed it:

su -
passwrd:

mkdir /usr/local/src
cd /usr/local/src

gunzip /tmp/gcc-3.3.1.tar.gz #where I downloaded the file
tar xvf /tmp/gcc-3.3.1.tar

cd /opt/build
/usr/local/src/gcc-3.3.1/configure
--prefix=/usr --libdir=/usr/lib --with-slibdir=/lib --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --enable-long-long --enable-__cxa_atexit --enable-languages=c,c++,ada,f77,objc,java --host=i586-mandrake-linux-gnu --with-system-zlib

make
make install

After I have done all these, I used "which, whereis, -v, and --version" to check the version of GCC.

I can see the system holds two versions of gcc, and if I didn't guess it wrong, the system is still using the old gcc-3.2 as the default.

I have two questions here:
First, how could I set system to use gcc-3.3.1? Someone told me because gcc-3.2 was installed in /usr/bin and gcc-3.3.1 was in /usr/local/bin so I have to change the order in $PATH. I didn't understand that clear, so I went to ~/.bashrc and changed it. But after I rebooted the system, I saw the system was still using gcc-3.2. As a newbie, I hope someone could walk me through it step-by-step or even a little tip will be appreciated.
My second question is about removing the older version of gcc. I don't think I need two versions of gcc in my system since they require space. I want to remove the older version. My Mandrake 9.0 uses rpm to install gcc-3.2 in the system, so I tried to use "rpm -e gcc" to delete the old version. I failed because of the software dependency. Is there any way to remove it and not hurting my other programs have installed in my computer?

Thanx in advanced.

HOUSCOUS

Just from your log it seems 3.3.1 is used, because gcc -v gives 3.3.1. On many systems, /usr/local comes before /usr in PATH. So if you have a version in /usr/local, it is usually the one that is loaded if you don't qualify with the absolute path.

You shouldn't delete 3.2, and in fact you should generally not remove the system-shipped gcc from your system.

If I don't interpret wrongly, because all of your libraries shipped in your RPMs were compiled using gcc 3.2, if you later on want to compile packages using these libraries, your gcc3.3 will not link those libraries unless they are recompiled using the new compiler. If you force remove gcc3.2 I guess you will break a lot of things. That's what I was told, and I need clarification on this too. gcc is not just another software package. It is the central component of any Linux and BSD systems that affects many parts of the system, and if that is not done carefully, you will likely wreck your system.

If you really have to stay with the latest compiler, use Debian unstable, because packages of the libraries compiled with that compiler will also be available with each compiler release. For example, the gcc version I have here is 3.3.2 with all necessary patches. That is by far the safest way to go.

Thanx cbkihong!