Commands using iptables (37)

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

loop over a set of items that contain spaces
If you want to operate on a set of items in Bash, and at least one of them contains spaces, the `for` loop isn't going to work the way you might expect. For example, if the current dir has two files, named "file" and "file 2", this would loop 3 times (once each for "file", "file", and "2"): $ for ITEM in `ls`; do echo "$ITEM"; done Instead, use a while loop with `read`: $ ls | while read ITEM; do echo "$ITEM"; done

Rename files in batch

Stat each file in a directory
This will run stat on each file in the directory.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Reclaim standard in from the tty for a script that is in a pipeline
This will grab the controlling tty regardless of what STDOUT and STDERR are doing.

easy C shell math calculators
allows simple C shell access to the power of bc - never could figure out how to do the same thing with Bash - that's why I use tcsh most of the time.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Press enter and take a WebCam picture.
This command takes a 1280x1024 p picture from the webcam. If prefer it smaller, try changing the -s parameter: qqvga is the tiniest, vga is 640x480, svga is 800x600 and so on. Get your smile on and press enter! :)

Lock the hardware eject button of the cdrom
This command will lock the hardware eject button of your cdrom drive. Some uses are: 1: If you have a toddler and has discovered the cdrom button 2: If you are carrying a laptop in a bag or case and don't want it to eject if the button is inadvertently pressed. To unlock the button use: $ eject -i 0


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: