## eselect-gcc-user

eselect-gcc-user is a Gentoo eselect module that allow a user to specify which (installed) version of GCC to use without requiring super-user priviledges or modifying global system and affecting other users.

When used, it will modify the PATH environment variable to point to the wanted GCC version, but only for the specific user. This allow to install an up to date version of GCC but only use it for user specific code, while keeping a stable version for Gentoo to use on package compilation.

### Usage

The usage is relatively simple, as other eselect modules.

$ eselect gcc-user
Usage: eselect gcc-user <action> <options>

Standard actions:
help                      Display help text
usage                     Display usage information
version                   Display version information

Extra actions:
list                      List available gcc versions
set <version>             Set a GCC version
    version                   Version or number to use (from 'list' action)
show                      Show the user's current GCC version.
unset                     Unset user selected GCC version

To set a specific version:

$ eselect gcc-user list
Available gcc versions:
[1]   4.5.3 *
[2]   4.7.0
$ eselect gcc-user set 4.7.0
GCC version set to 4.7.0
Remember to source profile files (or logout-login):
source /etc/profile && source ~/.bashrc
$ source /etc/profile && source ~/.bashrc
$ eselect gcc-user list
Available gcc versions:
[1]   4.5.3
[2]   4.7.0 *
$ which gcc
/usr/x86_64-pc-linux-gnu/gcc-bin/4.7.0/gcc
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.7.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /var/tmp/portage/sys-devel/gcc-4.7.0/work/gcc-4.7.0/configure
--prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.7.0
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.7.0/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.7.0/include/g++-v4
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --disable-altivec
--disable-fixed-point --without-ppl --without-cloog --enable-lto --enable-nls
--without-included-gettext --with-system-zlib --disable-werror --enable-secureplt
--enable-multilib --with-multilib-list=m32,m64 --enable-libmudflap
--disable-libssp --enable-libgomp --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/python
--enable-checking=release --disable-libgcj --enable-languages=c,c++,fortran --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-targets=all
--with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.7.0 p1.1, pie-0.5.3'
Thread model: posix
gcc version 4.7.0 (Gentoo 4.7.0 p1.1, pie-0.5.3)

### Issues

• No ebuild for the moment. Just copy/simlink these files:
  • /usr/share/eselect/modules/gcc-user.eselect
  • /etc/profile.d/gcc-user.sh
  • /etc/profile.d/remove_path_from_list_def.sh
• Does not work with dev-util/colorgcc: dev-util/colorgcc will always pick up the system wide GCC.
• There is no indication if the used version is the system-wide version or a specified one. If no version is explicitely set, the active version will be shown (as reported by gcc-config -c).
• It's playing with PATH variable, it might hurt kittens!