Show a Command's Short Description

whatis [command-name]
The whatis command displays a short description for the command you list on the command line. It is useful to quickly learn what a command does
Sample Output
$ whatis w who users
w                    (1)  - Show who is logged on and what they are doing
who                  (1)  - show who is logged on
who                  (1p)  - display who is on the system
users                (1)  - print the user names of users currently logged in to the current host

5
By: haivu
2009-04-02 17:30:13

These Might Interest You

  • This is the best way I have found to search out an application when I am not sure the title. Grep is just to remove anything that does not contain the term in the title or short description (lots of things might include the search term in the description, such as libraries used by the application) Show Sample Output


    0
    aptitude search ~d "irc client"|grep -i "irc client"
    tomjrace · 2011-07-11 19:48:55 0
  • Given a file with the format of 'git log --pretty=short', search in last 100 commits for one with the same description. I used this when after a rebase I had to find out the new commit ids. The second sed replaces all special characters with dots so they don't mess up the grep later on. Show Sample Output


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    cat /tmp/commit_list | { while read old_commit ; do msg="`git log --pretty=oneline $old_commit'^'..$old_commit | sed 's/[0-9a-f]* //' | sed 's/[^A-Za-z0-9]/./g'`"; git log --pretty=oneline HEAD@'{100}'..HEAD | grep "$msg" ; done ; }
    plexus · 2012-10-11 11:06:40 0
  • This, like the other commands listed here, displays installed arch packages. Unlike the other ones this also displays the short description so you can see what that package does without having to go to google. It also shows the largest packages on top. You can optionally pipe this through head to display an arbitrary number of the largest packages installed (e.g. ... | head -30 # for the largest 30 packages installed) Show Sample Output


    -1
    pacman -Qi | grep 'Name\|Size\|Description' | cut -d: -f2 | paste - - - | awk -F'\t' '{ print $2, "\t", $1, "\t", $3 }' | sort -rn
    GetterNoCheddar · 2012-11-20 03:40:55 0
  • This functionality seems to be missing from commands like dpkg. Ideally, I want to duplicate the behavior of rpm --verify, but it seems difficult to do this in one relatively short command pipeline. Show Sample Output


    0
    dpkg-query -Wf '${Package}\n' | xargs dpkg --status | sed '/^Conffiles:/,/^Description:/!d;//d' | awk '{print $2 " " $1}' | md5sum -c 2>/dev/null | grep FAILED$ | cut -f1 -d':'
    hallmarc · 2013-01-31 16:52:38 0

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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