Commands by lme (5)

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Check Ram Speed and Type in Linux
from http://maysayadkaba.blogspot.com/2008/08/linux-check-ram-speed-and-type.html

Securely destroy data on given device
Intentional hash in the beginning. May run a looong time. Wipes your data for real. Was meant to be /dev/urandom - I mistyped it. :-)

find broken symbolic links
== remove broken links == find -L . -type l -exec rm -rf {} \; == how this work == "symbolic link; this is never true if the -L option or the -follow option is in effect, unless the symbolic link is broken. If you want to search for symbolic links when -L is in effect, use -xtype." -- manpage of find.

Look up a unicode character by name
[Update! Thanks to a tip from ioggstream, I've fixed both of the bugs mentioned below.] You, yes, 𝙔𝙊𝙐, can be the terror of the Internet! Why use normal, boring bullet points in your text, when you could use a ROTATED HEAVY BLACK HEART BULLET (❥)!? (Which would also be an awesome band name, by the way).  This script makes it easy to find unusual characters from the command line. You can then cut and paste them or, if you're using a GTK application, type Control+Shift+U followed by the code point number (e.g., 2765) and then a SPACE.  USAGE: Put this script in a file (I called mine "ugrep") and make it executable. Run it from the command line like so,  $ ugrep heart  The output will look like this,  ☙ U+2619 REVERSED ROTATED FLORAL HEART BULLET ♡ U+2661 WHITE HEART SUIT ♥ U+2665 BLACK HEART SUIT ❣ U+2763 HEAVY HEART EXCLAMATION MARK ORNAMENT ❤ U+2764 HEAVY BLACK HEART ❥ U+2765 ROTATED HEAVY BLACK HEART BULLET ❦ U+2766 FLORAL HEART ❧ U+2767 ROTATED FLORAL HEART BULLET ⺖ U+2E96 CJK RADICAL HEART ONE ⺗ U+2E97 CJK RADICAL HEART TWO ⼼ U+2F3C KANGXI RADICAL HEART  You can, of course, use regular expressions. For example, if you are looking for the "pi" symbol, you could do this:  $ ugrep '\bpi\b'  REQUIREMENTS: Although this is written in Bash, it assumes you have Perl installed because it greps through the Perl Unicode character name module (/usr/lib/perl5/Unicode/CharName.pm). Note that it would not have made more sense to write this in Perl, since the CharName.pm module doesn't actually include a subroutine for looking up a character based on the description. (Weird.)  BUGS: In order to fit this script in the commandlinefu limits, a couple bugs were added. ① Astral characters beyond the BMP (basic multilingual plane) are not displayed correctly, but see below. ② Perl code from the perl module being grepped is sometimes extraneously matched.  MISFEATURES: Bash's printf cannot, given a Unicode codepoint, print the resulting character to the terminal. GNU's coreutils printf (usually "/usr/bin/printf") can do so, but it is brokenly pedantic about how many hexadecimal digits follow the escape sequence and will actually die with an error if you give the wrong number. This is especially annoying since Unicode code points are usually variable length with implied leading zeros. The CharNames.pm file represents BMP characters as 4 hexits, but astral characters as 5. In the actual version of this script that I use, I've kludged around this misfeature by zero-padding to 8 hexits like so,  $ /usr/bin/printf "\U$(printf "%08x" 0x$hex)"  TIP 1: The author recommends "xsel" for command line cut-and-paste. For example,  $ ugrep biohazard | xsel  TIP 2: In Emacs, instead of running this command in a subshell, you can type Unicode code points directly by pressing Control-Q first, but you'll likely want to change the default input from octal to hexadecimal. (setq read-quoted-char-radix 16).  TIP 3: Of course, if you're using X, and you want to type one of the more common unusual characters, it's easiest of all to do it with your Compose (aka Multi) key. For example, hitting [Compose] <3 types ♥.

Execute a command at a given time

Generate Random Text based on Length
Random text of length "$1" without the useless cat command.

Use tcpdump to monitor all DNS queries and responses

find an unused unprivileged TCP port
Some commands (such as netcat) have a port option but how can you know which ports are unused?

Gets the X11 Screen resolution
Requires xrandr, grep and, sed.

Create QR codes from a URL.
QR codes are those funny square 2d bar codes that everyone seems to be pointing their smart phones at. Try the following... $ qrurl http://xkcd.com Then open qr.*.png in your favorite image viewer. Point your the bar code reader on your smart phone at the code, and you'll shortly be reading xkcd on your phone. URLs are not the only thing that can be encoded by QR codes... short texts (to around 2K) can be encoded this way, although this function doesn't do any URL encoding, so unless you want to do that by hand it won't be useful for that.


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