Ccache的编译速度加速
c++的编译真的是太慢了， ccache说是能提高编译速度，安装ccache会在/usr/lib64/ccache目录创建工具的链接
[root@localhost]# ls -lh /usr/lib64/ccache/
total 0
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 c++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 cc -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 clang -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 clang++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 g++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 gcc -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 x86_64-redhat-linux-c++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 x86_64-redhat-linux-g++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root 16 Apr 9 15:12 x86_64-redhat-linux-gcc -> ../../bin/ccache
所以先执行
declare -x PATH="/usr/lib64/ccache:$PATH"
再编译就会使用ccache，ccache默认创建的缓存会放到个人$HOME目录 ~/.ccache 这个位置里面去。
其实centos 8安装完他默认就启用了，要禁用ccache需要在自己的~/.bash_profilew文件里面 export CCACHE_DISABLE=1 禁用了才行
[root@localhost ]# cat /etc/profile.d/ccache.sh
# Use ccache by default. Users who don't want that can set the CCACHE_DISABLE
# environment variable in their personal profile.
试了一个实际的项目，编译速度从4分钟左右降到2分钟左右吧。
man ccache
https://github.com/ccache/ccache/blob/master/doc/MANUAL.adoc