ports

1- Configuration
====================
In order to get ccache working, you will need to prepend for each user( root, $USER...) /usr/lib/ccache to 
your PATH which is declared and read through .profile or .bash_profile.
You can achieve this by the following oneshot command (to be repeated each time you compile)
export PATH=/usr/lib/ccache:$PATH.
You can put the full PATH value in one of those files as well. This new value will be read at each connection. 

2- Checking
===================
You may check your new setup by the following command
which gcc # (cc, clang...)
It should return at least this value for gcc
/usr/lib/ccache/gcc

3- Results
====================
The first compilation will result in a normal time duration, but if you compile the same input the next
time, you will obtain a fairly reduced elapsed time duration.
Tested: Full Linux kernel compiling 45 minutes. Second compilation 8 minutes.

4- Help functions
====================

Usage:
    ccache [options]
    ccache compiler [compiler options]
    compiler [compiler options]          (via symbolic link)

Options:
    -c, --cleanup         delete old files and recalculate size counters
                          (normally not needed as this is done automatically)
    -C, --clear           clear the cache completely (except configuration)
    -F, --max-files=N     set maximum number of files in cache to N (use 0 for
                          no limit)
    -k, --get-config=K    get the value of the configuration key K
    -M, --max-size=SIZE   set maximum size of cache to SIZE (use 0 for no
                          limit); available suffixes: k, M, G, T (decimal) and
                          Ki, Mi, Gi, Ti (binary); default suffix: G
    -o, --set-config=K=V  set configuration key K to value V
    -p, --print-config    print current configuration options
    -s, --show-stats      show statistics summary
    -z, --zero-stats      zero statistics counters

    -h, --help            print this help text
    -V, --version         print version and copyright information

See also <https://ccache.samba.org>.