Commands by drizzt (2)

  • Useful if you f.i. want to block/allow all connections from a certain provider which uses successive netnames for his ip blocks. In this example I used the german Deutsche Telekom which has DTAG-DIAL followed by a number as netname for the dial in pools. There are - as always ;) - different ways to do this. If you have seq available you can use net=DTAG-DIAL ; for i in `seq 1 30`; do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; done or without seq you can use bash brace expansion net=DTAG-DIAL ; for i in {1..30}; do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; done or if you like while better than for use something like net=DTAG-DIAL ; i=1 ; while true ; do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; test $i = 30 && break ; i=$(expr $i + 1) ; done and so on. Show Sample Output


    2
    net=DTAG-DIAL ; for (( i=1; i<30; i++ )); do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; done
    drizzt · 2009-08-01 05:28:19 0
  • Query Wikipedia by issuing a DNS query for a TXT record. The TXT record will also include a short URL to the complete corresponding Wikipedia entry.You can also write a little shell script like: $ cat wikisole.sh #!/bin/sh dig +short txt ${1}.wp.dg.cx and run it like ./wikisole.sh unix were your first option ($1) will be used as search term. Show Sample Output


    209
    dig +short txt <keyword>.wp.dg.cx
    drizzt · 2009-07-31 16:08:59 33

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

ssh autocomplete based on ~/.ssh/config
I use this in my bashrc to expand hosts defined in ~/.ssh/config: function _ssh_completion() { perl -ne 'print "$1 " if /^Host (.+)$/' ~/.ssh/config } complete -W "$(_ssh_completion)" ssh Here's a great article on how to setup your own ~/.ssh/config: http://blogs.perl.org/users/smylers/2011/08/ssh-productivity-tips.html

List 10 largest directories in current directory
du -m option to not go across mounts (you usually want to run that command to find what to destroy in that partition) -a option to also list . files -k to display in kilobytes sort -n to sort in numerical order, biggest files last tail -10 to only display biggest 10

Show a prettified list of nearby wireless APs

Show exit status of all portions of a piped command eg. ls |this_doesn't_exist |wc

Create a new file

Get just the IP for a hostname

Create a tar archive using xz compression
Compress files or a directory to xz format. XZ has superior and faster compression than bzip2 in most cases. XZ is superior to 7zip format because it can save file permissions and other metadata data.

Vim: Switch from Horizontal split to Vertical split
This allows to switch from horizontal to vertical split, putting the current buffer on the right side of the vertical split. To put it on the right use ^W-H. In a similar way, to switch from Vertical to Horizontal, do ^W-J (for bottom) and ^W-K (for top), but you vimers all guessed that one already :P

Make the Mac OS X Dock 2D once more (10.5 and above only)
Mac OS X 10.5 (Leopard) introduced a new, 3D, reflective Dock. For those of us who prefer the Dock to be a little less distracting, this command is the answer. The Dock will be rendered in the same style as when pinned to the left- or right-hand side of the screen. Replace YES with NO to restore the 3D Dock.

Display the human-readable sizes of all files and folders in the current directory with 3 decimal places
To sort the list by file/directory size, insert `sort -n |` before `awk`.


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: