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Scott Ritchie
Asked: 2012-03-05 21:25:50 +0800 CST

How do I find a list of packages with Priority: Required?

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I want to find a list of all packages with the Priority: field set to Required. These are packages that are normally installed on every system, however I've recently discovered that they aren't necessarily installed for foreign architectures using multiarch. What's the best way to find these packages?

aptitude apt-cache

2 Answers

  1. Best Answer

    With aptitude you can do that type of search.

    aptitude search '?priority(required)'

    Note that aptitude is no longer installed by default on newer Ubuntu releases, and its man-page is incomplete; you'll find the full documentation as /usr/share/doc/aptitude/README

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  2. (Disclaimer: this answer uses a low level system tool to solve the requested problem, not aptitude. But since aptitude relies on dpkg services, it might still be useful.)

    You can make use of dpkg-query combined with grep:

    dpkg-query -W --showformat='${Package}\t${Priority}\n' | grep "required$"
    • dpkg-query lists all packages, when no package name is specified.
    • The -W or (--show) allows for listing packages using a specified output format.
    • The output format is provided by the --showformat='formatstring' syntax. The string consists of:
      • ${Package} to display the package name.
      • \t to display a Tab character as field separator.
      • ${Priority} to display the package priority.
      • \n to display a newline character at the end of each line.

    Since a sample output without grep looks like this:

    klibc-utils required
kmod    required
krb5-locales    standard
lame    optional
landscape-client-ui-install optional
language-pack-en    optional

    The grep command displays only lines containing the „required” word at the end, i.e. the packages with Priority: required.

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