Commands using perl (369)

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Get a list of IP Addresses that have failed to login via SSH
This command shows a sorted list of the IP addresses from which there have been authentication errors via SSH (possible script kiddies trying to gain access to your server), it eliminates duplicates so it's easier to read, but you can remove the "uniq" command at the end, or even do a "uniq -c" to have a count of how many times each IP address shows in the log (the path to the log may vary from system to system)

Check if a machine is online with better UI
I have used single packet, and in a silent mode with no display of ping stats. This is with color and UI improvement to the http://www.commandlinefu.com/commands/view/10220/check-if-a-machine-is-online. It is as per the enhancements suggested.

use the real 'rm', distribution brain-damage notwithstanding
The backslash avoids any 'rm' alias that might be present and runs the 'rm' command in $PATH instead. In a misguided attempt to be more "friendly", some Linux distributions (or sites/etc.) alias 'rm' to 'rm -i'. Unfortunately, this trains users to expect that files won't actually be deleted until they okay it. This expectation will fail with catastrophic results when they use other distributions, move to other sites, etc., and doesn't really even work 100% even with the alias. It's too late to fix 'rm', but '\rm' should work everywhere (under bash).

Restrict the use of dmesg for current user/session
Linux offers an interesting option to restrict the use of dmesg. It is available via /proc/sys/kernel/dmesg_restrict. You can check the status with: $ cat /proc/sys/kernel/dmesg_restrict Alternatively you can use sysctl: $ sudo sysctl -w kernel.dmesg_restrict=1 To make your change persistent across reboot, edit a fille in /etc/sysctl.d/.

Clean apt-get and gpg cache and keys
Cleans apt-get and gpg cache and keys

Extract tar content without leading parent directory
If archive has leading directory level same as archive name and you want to strip it, this command is for you.

Pulls email password out of Plesk database for given email address.
This simply pulls the password out of the database for the given mail name for ease of use in testing emails that you would not normally have access to.

Test for Weak SSL Ciphers
...if you get a certificate back, the server is accepting weak SSL ciphers

Convert IP octets to HEX with no dots.
Converts IP octets to hex using printf command. Useful for generating pxeboot aliases in the pxelinux.cfg folder.

list block devices
Shows all block devices in a tree with descruptions of what they are.


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