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user43816
Asked: 2012-06-10 01:09:04 +0800 CST

Why is cat running as a daemon on Ubuntu 12.04?

  • 772

/bin/cat appears to be running as a persistent daemon on my 12.04 system.

$ ps aux | grep cat

detlef 2278 0.0 0.0 8680 352 ? S 06:13 0:00 /bin/cat

Why does Ubuntu 12.04 need cat running as a daemon? It didn't on my 10.04.4 system.

12.04

1 Answers

  1. Best Answer

    cat is running as part of the Unity Dash Text-Search service (zeitgeist-fts)

    cat is not a daemon; conCATenate is a utility which joins one or more input files into a single output file.

    • /bin/cat runs on Ubuntu 12.04 as a part of the Zeitgeist service, which logs events, history, etc. and also enables the search-as-you-type in the dash feature.

    • Specifically, it is started by zeitgeist-fts (Zeitgeist Full-Text-Search), which is the Zeitgeist component providing the search feature.

    • Proof: notice the PID of cat (3082) in ps andpstree output:

      $ ps aux | grep /bin/cat
      izx       3082  0.0  0.0  11372   568 ?        S    Jun08   0:00 /bin/cat
      and 
      $ pstree -p | grep zeit
      ├─zeitgeist-daemo(3051)───{zeitgeist-daemo}(3061)
    ├─zeitgeist-datah(3076)───{zeitgeist-datah}(3081)
    └─zeitgeist-fts(3075)─┬─cat(3082)
                          └─{zeitgeist-fts}(3080)

    • Zeitgeist/Unity did not exist in 10.04, so no cat either! As for why it's needed, cat is universally used for text processing, and the function of its parent zeitgeist-fts is...text processing :)

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