gcc和g++都是GUN（組織）的編譯器。
gcc是C編譯器
g++是C++編譯器
linux下cc一般是一個符號連接，指向gcc
ls /usr/bin
下面是linux自帶的autoconf工具
-rwxr-xr-x. 1 root root 14631 Nov 11 2010 autoconf
-rwxr-xr-x. 1 root root 8484 Nov 11 2010 autoheader
-rwxr-xr-x. 1 root root 31789 Nov 11 2010 autom4te
-rwxr-xr-x. 2 root root 257062 Feb 22 2013 automake
-rwxr-xr-x. 2 root root 257062 Feb 22 2013 automake-1.11
-rwxr-xr-x. 1 root root 20233 Nov 11 2010 autoreconf
-rwxr-xr-x. 1 root root 17065 Nov 11 2010 autoscan
-rwxr-xr-x. 1 root root 33766 Nov 11 2010 autoupdate
下面是linux自帶的c語言編譯器
-rwxr-xr-x. 4 root root 243208 Nov 21 2013 c++
-rwxr-xr-x. 4 root root 243208 Nov 21 2013 g++
-rwxr-xr-x. 1 root root 224 Nov 21 2013 c89
-rwxr-xr-x. 1 root root 215 Nov 21 2013 c99
lrwxrwxrwx. 1 root root 3 Sep 11 2014 cc -> gcc
-rwxr-xr-x. 1 root root 26356 Feb 22 2013 c++filt