Refreshing Drink of Ideas

Linux / Unix Notes

This article is a list of notes I've collected to help me with Linux and/or Unix.  Please don't consider this a comprehensive reference.  I'm not a Linux or Unix expert.  These notes are just some things I've had to remember but always seem to forget when I've had to log onto a Linux or Unix machine for the following:
  • Setting up a website.  I think Linux is the easiest platform and has the most tools, free and open, readily available.
  • Attempting to develop an application for my Android phone (which uses a form a Unix) and experimenting with root access with a command prompt.
  • Hacking my older Directv Tivo DVR
I've never tried or even had much interest in using Linux and X11 windows as an alternative to MS Windows for my desktop.  So there won't be any notes about that in this article.

There are certainly more comprehensive and accessible Linux/Unix references out there on other websites.  However, because there were some things I couldn't find quickly enough or expressed simply enough or whatever, I found I needed to write my own notes.  These notes are now here where I can find them no matter where I am.  They are also for anybody else, due to being in the same situation for frame of mind as me, has Googled here for the quickest answer.

Wherever I list a shell command, the shell will most likely be Bash with a prompt of "$".   The commands can be used interactively from a terminal or from within a shell script.  Here are the notes below.


Display which shell processor is being used to interpret your commands at the command line:
$ echo $0
The above will echo out the name of the shell.  For example the output may be:
-bash
Alternatively to get the full path to the shell processor, do the following:
$ echo $SHELL

Listing the contents of a directory

$ ls
List each item with full attributes
$ ls -l

To list even files that begin with "." because these are normally hidden
$ ls -l -a

To list files that begin with "." but excluding the implied directory names of "." (current) or ".." (parent)

$ ls -l -A

A file name or directory name, with or without wildcards ('*" or "?"), may be be provided to get directory limited to files or directories that match. 

$ ls -l -A <filename>

If shell is set up for it (Bash usually is), then the easier to remember "dir" command can be used

$ dir -l -A

For quick help on any command, try including "--help" option:

$ dir --help

For extensive help (when available) use the "man" command:
$ man set
The above command will list out a manual article on the "set" command


Displaying the current directory (or working directory):
$ pwd

Changing the current directory - for example, to a directory called "public_html" under the current:
$ cd  public_html
A wildcard will make this quicker and easier to type if "public_html" is the only directory that begins with "pub"
$ cd pub*

To make a new subdirectory:
$mkdir <directory name>

The Bash shell can show the host name and current directory in each prompt.  This is the default on many Linux systems.  Set variable PS1 as follows:
$ PS1="\u@\h:\w\$"
Variable PS1 defines the prompt string for Bash.  With special escape character "\" commands cause system values to be inserted.  A good explanation for this was found at on the web here.


Changing the terminal type that system expects you to have
Just set the TERM variable
$ TERM=vt100

Listing all variables with their values
$ set

Exporting variables to sub-processes:
The first command will cause all subsequently created or modified variables to be exported
$ set -a
The next command will specify a list of names to export
$ export <names>

Start a background process
In the below example, the "&" indicates that the given command has a requirement for terminal access
$ <command> &

List running processes
The following will list all processes user is allowed to view based on authorization level
$ ps -e
A root user would be able to see all processes running on the system with the above.  A non-privileged user would only be able to see his own.

Use --help to see more options.


Execute a command as another user

This is may be allowed only if a privileged user.  Also may prompt for password. 

su -c "<command>" <userid>

Sending the output of one command to be processed by another, use the pipe character "|".   The standard output of 1st (normally printed on terminal display) of will be sent as the standard input (normally from terminal keyboard) to the 2nd.

Example using grep processor to list out any running process that contains a certain string ("bash") in its name

$ ps -e | grep "bash"

To control flow of output to the screen
Pipe output to "more" processor
$ set | more
The above list all variables ("set") by sending one page of output to the terminal at a time.  Key "q" or cntrl-c to stop.  Any other key will go to next page.

A better processor to use is "less"
$ set  | less
The above will list all variables by 1st sending 1st page of output to the terminal.  The "q"  key will stop.  Keyboard up and down arrow keys will allow navigating up and down one line at a time.  Space key will move a page at a time.  Other keys may do other things so look this up in "man" or use
$ less --help

Forthstar - clock 23:55:27 - Saturday, 24.04.10 - Linux / Unix - 4173043x - pencil permalink
Karma points: 5232. Do you like this article? [yes/no]

RSS 2.0 feed, Trackback, print preview, email this article

  • RSS 2.0 feed of this article, including comments:  RSS 2.0 comments feed
  • Use this Trackback URL for ping (right mouse click and copy URL).
  • You can [print] this article, [email] it, or export a [PDF].

Local search Linux Unix Notes

No results found or search not configured.

Google search

No results found or search not configured.

Add new comment:

Comments must be approved before being published. Thank you!

Preview and Confirm Your Comment!

<img>http://i.imgur.com/w4EobfM.png</img>

GET UNLIMITED PLANTSVSZOMBIES RESOURCES!

Backyard Battleground is the container for everything in Garden Warfare 2. The cactus's potato mines can fortify a location against zombies who are too reckless to look where they're going. forcing burrowed chompers out of the ground in the process. both of whom are now far more intelligent compared to the original Garden Warfare. which at least simplifies the process. but a pirate just set me on fire and now I need to find a sunflower so I don't die before my team destroys the giant boot battering our castle gate. Plants vs. and the closest thing to the original Plants vs Zombies tower defense gameplay. Driving home the last few shots on a final target just before dying is super satisfying. bringing Plants and Zombies to seven each. I've unlocked almost no hidden areas. It's also an excuse to bombard players with puns and dad jokes. Wayward zombies or plants are worth experience in Zomburbia as well as in the cooperative Garden Ops mode. It’s a horde-like survival mode. goofy charm of casual-friendly developer PopCap's overhead strategy game Plants vs. One level is packed with hills and tall buildings. How unnecessary. for example. so Garden Ops lacks the liveliness of the competitive modes. The plants and zombies receive three new characters apiece.
plants vs zombies hacked full version download
plants vs zombies cheat 6.1
plants vs zombies cheats yahoo
plant vs zombies hack engine
plants vs zombies full version unlimited
plants vs zombies cheats 100 feet
plants vs zombies 1 hacked
plants vs zombies text generator
plants vs zombies 2 hack iphone
plants vs zombies cheat hacked
plants vs zombies cheats of infinite sun
plants vs zombies infinite sun no recharge
plants vs zombies garden warfare product key generator
plants vs zombies 2 ipad cheats jailbreak
dl4all search plants vs zombies order number generator
plants vs zombies hack zomboss
plants vs zombies cheat recharge
plants vs zombies hack jailbreak
plants vs zombies 2 cheat without jailbreak
plants vs zombies infinite gold cheat engine
plants vs zombies hacked full version free
plants vs zombies unlimited sun on ipad
plants vs zombies goty unlimited money
plants vs zombies cheats 4-1
plants vs zombies cheats + 21
Throne Rush Hack Direct Download. Throne Rush Cheat Tool Update V.3.5 To 3.6.RarThrone Rush Hack By Cheat Engine. Throne Rush Cheat On AndroidThrone Rush Hack 2016. Cheat Za Throne RushThrone Rush Apk Unlimited Money. Throne Rush Hack Tool YoutubeThrone Rush Cheat Kaskus. Cheat 1 Hit Throne Rush
plants vs zombies 2 hack v3.0
plants vs zombies recharge hack cheat engine
plants vs zombies 2 1.5 unlimited money
plants vs zombies 2 unlimited everything
plants vs zombies 2 hack v1.1
plants vs zombies cheat level 5 9
plants vs zombies 2 unlimited diamonds ipad
plants vs zombies 2 cheats
cheats for plants vs zombies unlimited sun
plants vs zombies unlimited sun
plants vs zombies unlimited money cheat engine 6.2
hack plants vs zombies 2 trung quoc
plants vs zombies bluestacks hack
plants vs zombies serial key generator
plants vs zombies cheat engine 6.3
plants vs zombies 2 infinite levels
plants vs zombies unlimited money iphone
plants vs zombies cheats nintendo 3ds
plants vs zombies cheats iphone unlimited sun
plant vs zombie unlimited gold cheat
order number for plants vs zombies generator
plants vs zombies cheat unlimited sun
plants vs zombies money hack cheat engine 5.5
plants vs zombies infinite money no cheat engine
plants vs zombies hack para iphone
Throne Rush Cheat Activation Code. Throne Rush Cheat For MobileThrone Rush Hack Direct Download. Throne Rush Cheats For Windows 7Throne Rush Unlimited Gems Facebook. Throne Rush Hack Yahoo AnswersThrone Rush Hack Tool. Throne Rush Cheat ManaUnlimited Units In Throne Rush (Cheat Engine 6.3). Cheats Para O Throne Rush

Spam control