Linux Fix It

Today I was teaching a kid who recently got promoted at work how to use dd, dd is a fairly simple linux command that allows you to copy the contents of one drive to an other.

Being Paranoid is a good thing. Its also a bad thing!

If you have sensitive data, and which geek doesn't! You need to start using the shred command.

shred's syntax is shred [option(s)] file(s)_or_devices(s)

Why use shred? Due to the fact that deleting a file with the rm command does not actually destroy the data, it removes the index listing. So all the data is still on your hard drive.

Today I was making a comparator and I started to think to my self what is faster a comparator, test, [, or [[, was fastest?

We need to use the time command to make sure we can find the results.

$ time for i in {1..100000}; do [[ -d . ]];done
real 0m1.256s
user 0m1.018s
sys 0m0.238s

$ time for i in {1..100000}; do [ -d . ];done
real 0m3.407s
user 0m2.704s
sys 0m0.703s

$ time for i in {1..100000}; do test -d .;done
real 0m3.223s
user 0m2.607s
sys 0m0.616s

Welcome to Tuesday's Tips for shell scripting.
These tips come from my own scripting as well as answers I have provided to queries in various usenet newgroups (e.g., comp.unix.shell and comp.os.linux.misc).
The series ran from April to September, at which time I began work on a book of shell scripts. Due to the demands that project made on my time, I was unable to continue the series.
The Easy PATH (28 Sep 2004)
flocate — locate a file (21 Sep 2004)
Toggling a variable (31 Aug 2004)
Redirecting stdout and stderr (24 Aug 2004)

Ever since I was born every measurable trend indicated faster networks, and multi-processor computer architectures this huge data set clearly show that parallelism is the future of computing.

In Parallel Processing you need to understand the how and whys before jumping into programming. Here is the webs best link as of today. https://computing.llnl.gov/tutorials/parallel_comp/ read on, and then come back for the meat and potatoes!

Bash brace expansion is used to generate stings at the command line or in a shell script. The syntax for brace expansion consists of either a sequence specification or a comma separated list of items inside curly braces "{}". A sequence consists of a starting and ending item separated by two periods "..".

Many Linux commands accept multiple file or directory names as arguments.

# list some files
$ ls -l a.txt b.txt c.txt

# copy some files
$ cp a.txt b.txt c.txt backup

# remove some files
$ rm a.txt b.txt c.txt

To be honest, one of my least favorite past times is to browse large enterprise level network file systems. Every blue moon richie will come and ask, hey tr can you find that xkcd wanna be comic I made back in 2006 or 2007.

As slowly as I can I reply "I think I deleted it I always reply!" Then for dramatic effect pause again for at least a minute, " Just Kidding!"

Voiceless it cries, wingless flutters, toothless bites, mouthless mutters

It cannot be seen,cannot be felt, cannot be heard, cannot be smelt, it lies behind stars and under hills, and empty holes it fills

Alive without breath, as cold as death, never thirsty, ever drinking, when tired, never winking.

Dies half its life, lives the rest, dances without music, breathes without breath

Vim's syntax highlighting and color schemes can be a blessing, or a curse, depending on how they're configured. If you're a Vim user, let's take a little time to explore how you can make the most of Vim's color schemes.

One of the things that I love about Vim is syntax highlighting. I spend a lot of time working with HTML, for instance, and the syntax highlighting makes it much easier to spot errors. However, there's times when the default Vim colors and the default terminal colors don't play well with one another.