Commands by anarcat (11)

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Display rows and columns of random numbers with awk
Displays six rows and five columns of random numbers between 0 and 1. If you need only one column, you can dispense with the "for" loop.

Remove all cached images for icons related to your profile
Run inside Command Prompt (cmd.exe) as admin. Note that you must close explorer.exe first, and even so some files will not be deleted, will say "Access is denied." To definitely delete them enter with another admin user or from other operating system and access the drive.

kill all running instances of wine and programs runned by it (exe)
Look mah! All pipes

See a full last history by expanding logrotated wtmp files
When your wtmp files are being logrotated, here's an easy way to unpack them all on the fly to see more than a week in the past. The rm is the primitive way to prevent symlink prediction attack.

Copy specific files to another machine, keeping the file hierarchy
Notes: * Adjust the find command to your own filters. * The -P flag forces to keep absolute paths in the tarball, so that you can be sure that the exact same file hierarchy will be created on the second machine.

Create a backup copy of a MySQL database on the same host
This should probably only be used for testing in a dev environment as it's not terribly efficient, but if you're doing something that might trash a DB and you still want the old data available, this works like a charm.

Block all IP addresses and domains that have attempted brute force SSH login to computer
Searches all log files (including archived bzip2 files) for invalid user and PAM authentication errors, both of which are indicative of brute force attempts at logging into computer. A list of all unique IP addresses and domain names is appended to hosts.deny. The command (and grep error messages) will work on Mac OS X 10.6, small adjustments may be needed for other OSs.

How to remove an ISO image from media database

Change the From: address on the fly for email sent from the command-line
It's very common to have cron jobs that send emails as their output, but the From: address is whatever account the cron job is running under, which is often not the address you want replies to go to. Here's a way to change the From: address right on the command line. What's happening here is that the "--" separates the options to the mail client from options for the sendmail backend. So the -f and -F get passed through to sendmail and interpreted there. This works on even on a system where postfix is the active mailer - looks like postfix supports the same options. I think it's possible to customize the From: address using mutt as a command line mailer also, but most servers don't have mutt preinstalled.

Start COMMAND, and kill it if still running after 5 seconds


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