Commands by Viaken (2)

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Webcam view with vlc
Quick command to test your webcam. Press 'f' to toggle fullscreen. Can also use 'vlc v4l2://' if you want gui controls. For higher/smoother framerate lower the default resolution: $ cvlc v4l2:// :v4l2-width=320 :v4l2-height=240 &

Compare directories via diff
http://hints.macworld.com/article.php?story=20070408062023352

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Check if running in an X session
If you want to display a dialog (using xdialog/kdialog/zenity) you need to make sure that you have a valid X session. Checks for the existence of the DISPLAY variable.

List all execs in $PATH, usefull for grepping the resulting list
##Dependancies: bash coreutils Many executables in $PATH have the keyword somewhere other than the beginning in their file names. The command is useful for exploring the executables in $PATH like this. $ find ${PATH//:/ } -executable -type f -printf "%f\n" |grep admin lpadmin time-admin network-admin svnadmin users-admin django-admin shares-admin services-admin

Find the package that installed a command

kills rapidly spawning processes that spawn faster than you can repeat the killall command
if you dont want to alias also then you can do killall rapidly_spawning_process ; !! ; !! ; !!

BASH one-liner to get the current week number
Not as cool as the python example, but it still works.

Check syntax of remote ruby file

Group OR'd commands where you expect only one to work
Something to stuff in an alias when you are working in multiple environments. The double-pipe OR will fall through until one of the commands succeeds, and the rest won't be executed. Any STDERR will fall out, but the STDOUT from the correct command will bubble out of the parenthesis to the less command, or some other command you specify.


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