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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.
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:
change ":" in path for new line and associate word path to var $PATH
Batch resize all images to a width of 'X' pixels while maintaing the aspect ratio.
This makes uses of ImageMagick to make life easier.
Find and replace specific characters in a single line in multiple files with sed.
Some malicious program appends a iframe or script tag to you web pages on some server, use this command to clean them in batch.
You can actually do the same thing with a combination of head and tail. For example, in a file of four lines, if you just want the middle two lines:
head -n3 sample.txt | tail -n2
Line 1 --\
Line 2 } These three lines are selected by head -n3,
Line 3 --/ this feeds the following filtered list to tail:
Line 2 \___ These two lines are filtered by tail -n2,
Line 3 / This results in:
being printed to screen (or wherever you redirect it).
You can replace "sort -nu" with "sort -u" for a word list sorted or "sort -R" for a random-sorted line
Here's a bash version using an array.
NOT MINE! Taken from hackzine.com blog.
It creates a tree-style output of all the (sub)folders and (sub)files from the current folder and down(deeper)
Quoting some of hackzine's words
"Murphy Mac sent us a link to a handy find/sed command that simulates the DOS tree command that you might be missing on your Mac or Linux box. [..split...] Like most things I've seen sed do, it does quite a bit in a single line of code and is completely impossible to read. Sure it's just a couple of substitutions, but like a jack in the box, it remains a surprise every time I run it."
This command allows you to find the effective uid and gid of the Apache process regardless of process name (which can be apache2 or httpd depending on distro).
1 rpm -ivh package.rpm
2 yum localinstall package.rpm
3 Edit /etc/yum.conf or repository.repo and change the value of gpgcheck from 1 to 0 (!dangerous)
Returns code of current status of pidgin accounts via dbus interface
So your boss wants to know how much memory has been assigned to each virtual machine running on your server... here's how to nab that information from the command line while logged in to that server
--vrdp on enables VirtualBox RDP server for the VM
--vrdpport 3389 ndicates the TCP port that the server will accept RDP connections direct to the VM (for each VM is assigned a different port)
--vrdpauthtype external RDP console gives access to the VM Host physical users via authentication
In fact, in the 3.1.x version of VirtualBox, the external value for the parameter --vrdpauthtype allows access via RDP only to the user who started the VM.
The workaround is to add the user that runs the VM to shadow group, using the command