Commands by Risthel (2)

  • Reload all sysctl variables without reboot

    Reload all defined kernel variables from /etc/sysctl.conf(if no parameter after -p is given) without the old myth "Ah, you'll need to reboot to apply those variables"... Show Sample Output


    1
    /sbin/sysctl -p
    Risthel · 2013-02-14 12:48:26 3
  • Export a postgresql query into csv file

    This command will "su" the execution of the command to the postgres user(implies that you are already logger as root), and export the result of the query to a file on the csv format. You'll need to adequate the fields and database information to one of your choice/need. Show Sample Output


    0
    # su -c "psql -d maillog -c \"copy (select date,sender,destination,subject from maillog where destination like '%domain.com%') to '/tmp/mails.csv' with csv;\" " postgres
    Risthel · 2013-02-13 13:03:17 4

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find all non-html files

Show a prettified list of nearby wireless APs

Parse YouTube url (get youtube video id)
url can be like any one of followings: $url="MejbOFk7H6c" $url="http://youtu.be/MejbOFk7H6c" $url="https://youtube.com/watch?feature=player_embedded&v=MejbOFk7H6c#t" $url="//www.youtube.com/v/MejbOFk7H6c?hl=ru_RU&version=3&rel=0" $url="http://www.youtube.com/embed/MejbOFk7H6c?feature=player_embedded" If url mismatching, whole url will be returned.

Copy a file to a new directory created on the fly
You need to cp, mv, scp, ..., some files around from one place to another, and after having laboriously typed out the source path, you remember that the destination directory doesn't yet exist, and so the command will fail. So rather than killing the command line and starting over, just interpolate the results of creating the directory and echo its name. You could DRY this with a for; do; done, but that may be more trouble than it's worth.

Repeat a command until stopped
In this case it runs the command 'curl localhost:3000/site/sha' waiting the amount of time in sleep, ie: 1 second between runs, appending each run to the console. This works well for any command where the output is less than your line width This is unlike watch, because watch always clears the display.

static compilation

Batch-Convert text file containing youtube links to mp3

list files recursively by size

Draw a Sierpinski triangle
OK, not the most useful but a good way to impress friends. Requires the "display" command from ImageMagick.

Numeric zero padding file rename
This uses Perl's rename utility (you may have to call it as prename on your box) and won't choke on spaces or other characters in filenames. It will also zero pad a number even in filenames like "vacation-4.jpg".

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