Commands using ls (517)

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Expedient hard disk temprature and load cycle stats
This command is a great way to check to see if acpi is doing damage to your disks by agressivly parking the read arm and wearing down it's life. As you can see, mine has lost half its life. I'm sure this could be shortened though somehow. It will use smartctl to dump the stats and then grep out just the temperature and load cycles for the disk (a load cycle is when a the read arm comes out of park and wears on the drive).

Start a local web server in the current directory on a random dynamic port.

Ping a URL sending output to file and STDOUT
The tee (as in "T" junction) command is very useful for redirecting output to two places.

Convert number of bytes to human readable filesize
Converts a number of bytes provided as input, to a human readable number.

list all opened ports on host

Securely destroy data on given device hugely faster than /dev/urandom
This command generates a pseudo-random data stream using aes-256-ctr with a seed set by /dev/urandom. Redirect to a block device for secure data scrambling.

get a mysqldump with a timestamp in the filename and gzip it all in one go
Performs a mysqldump and gzip-compresses the output file with a timestamp in the resulting dump file. Inspect the file for integrity or fun with this command afterward, if you desire: $ zcat mysqldump-2009-06-12-07.41.01.tgz | less

Change framebuffer font
setfont load vga console font. The default font directory is usually in /lib/kbd/consolefonts. Setfont is part of kbd package. Tested on CentOS.

generate random password
-B flag = don't include characters that can be confused for other characters (this helps when you give someone their password for the first time so they don't cause a lockout with, for example, denyhosts or fail2ban) -s flag = make a "secure", or hard-to-crack password -y flag = include special characters (not used in the example because so many people hate it -- however I recommend it) "1 10" = output 1 password, make it 10 characters in length For even more secure passwords please use the -y flag to include special characters like so: $ pwgen -Bsy 10 1 output>> }&^Y?.>7Wu

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"


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