anchor.diff:  The file available to `excludeImages` above, should contain either the name and version or the sha256 digest. +
   ```sh
   $ cat docker-garby.exclude
  -sha256:8e5aaa829fbdf9c04a9793e5c0ccb6e999a3dd8ba3fb198f38732a022266ca96
  -nginx:latest
  +sha256:47cf20d8c26c46fff71be614d9f54997edacfe8d46d51769706e5aba94b16f2b
  +konstruktoid/nginx:latest
   ```
   
   == Examples
  
positive.code: === Shell
  ```sh
  $ sh docker-garby.sh
  $ sudo journalctl SYSLOG_IDENTIFIER=docker-garby -r
  -- Logs begin at Tue 2016-06-28 09:26:37 CEST, end at Wed 2016-07-06 13:45:20 CEST. --
  Jul 06 13:45:19 tabdlab01 docker-garby[25641]: Image [konstruktoid/alpine:latest] (sha256:d879607f7403c3a12b1d5b0bc8d39e609d41be55b4a49923d33b08e897ad56de) removed.
  Jul 06 13:45:19 tabdlab01 docker-garby[25632]: Image [konstruktoid/alpine:latest] (sha256:d879607f7403c3a12b1d5b0bc8d39e609d41be55b4a49923d33b08e897ad56de) unused.
  Jul 06 13:45:19 tabdlab01 docker-garby[25623]: Image [alpine:3.3] (sha256:47cf20d8c26c46fff71be614d9f54997edacfe8d46d51769706e5aba94b16f2b) removed.
  Jul 06 13:45:19 tabdlab01 docker-garby[25614]: Image [alpine:3.3] (sha256:47cf20d8c26c46fff71be614d9f54997edacfe8d46d51769706e5aba94b16f2b) unused.
  Jul 06 13:45:19 tabdlab01 docker-garby[25605]: Image [cassandra:latest] (sha256:075b7d5e2ed5c2bc6ff6135d5864860fd494e191935276a3224de364be2cf5c2) removed.
  Jul 06 13:45:19 tabdlab01 docker-garby[25595]: Image [cassandra:latest] (sha256:075b7d5e2ed5c2bc6ff6135d5864860fd494e191935276a3224de364be2cf5c2) unused.
  Jul 06 13:45:19 tabdlab01 docker-garby[25586]: Image [nginx:latest] (sha256:0d409d33b27e47423b049f7f863faa08655a8c901749c2b25b93ca67d01a470d) excluded.
  Jul 06 13:45:19 tabdlab01 docker-garby[25573]: Image [] (sha256:8e5aaa829fbdf9c04a9793e5c0ccb6e999a3dd8ba3fb198f38732a022266ca96) excluded.
  Jul 06 13:45:18 tabdlab01 docker-garby[25550]: No containers found.
  Jul 06 13:44:42 tabdlab01 docker-garby[25137]: No dangling volumes found.
  Jul 06 13:44:41 tabdlab01 docker-garby[25126]: Image [nginx:latest] (sha256:0d409d33b27e47423b049f7f863faa08655a8c901749c2b25b93ca67d01a470d) excluded.
  Jul 06 13:44:41 tabdlab01 docker-garby[25113]: Image [] (sha256:8e5aaa829fbdf9c04a9793e5c0ccb6e999a3dd8ba3fb198f38732a022266ca96) excluded.
  Jul 06 13:44:41 tabdlab01 docker-garby[25090]: Container /compassionate_bose (ce534457da30) removed.
  Jul 06 13:44:41 tabdlab01 docker-garby[25081]: Container /compassionate_bose (ce534457da30) used image [].
  Jul 06 13:44:41 tabdlab01 docker-garby[25075]: Container /compassionate_bose (ce534457da30) finished 10701 seconds ago.
  Jul 06 13:44:41 tabdlab01 docker-garby[25042]: Container /jolly_allen (1492158818a3) removed.
  Jul 06 13:44:41 tabdlab01 docker-garby[25032]: Container /jolly_allen (1492158818a3) used image [konstruktoid/alpine:latest].
  Jul 06 13:44:41 tabdlab01 docker-garby[25026]: Container /jolly_allen (1492158818a3) finished 7509 seconds ago.
  Jul 06 13:44:41 tabdlab01 docker-garby[24993]: Container /sharp_jepsen (b86c0d5ab569) removed.
  Jul 06 13:44:41 tabdlab01 docker-garby[24984]: Container /sharp_jepsen (b86c0d5ab569) used image [konstruktoid/alpine:latest].
  Jul 06 13:44:41 tabdlab01 docker-garby[24978]: Container /sharp_jepsen (b86c0d5ab569) finished 7506 seconds ago.
  ```
  
  === Docker
  
negative.code: Just another Docker garbage collection script, written for Docker version 1.9 and later.
  
  == Configuration options
  The configuration options may be set in the script itself or at runtime. +
  `maxSecondsOld=600 pullExcluded=no sh docker-garby.sh` will remove a finished container older than 10 minutes
  and not pull excluded images. Excluded images are those you want to keep no matter what.
  
  `excludeImages="$(pwd)/docker-garby.exclude"` Exclude the images listed in this file. +
  `pullExcluded='yes'` Pull the latest version of the excluded images. +
  `logFile=''` Write to console. +
  `logFile='./docker-garby.log'` Write to a logfile, will be appended with `-$(date +%Y%m%d)`. +
  `logFile='syslog'` Write to syslog. +
  