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:
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 - 7823228x - pencil permalink
Karma points: 8555. 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!



Why? The FUT Price Range makes it much harder to get Coins by trading. Usted no tiene que pagar nada y. FIFA 16 Coins Generator is what you are searching For. your ID and your platform. Ibra or Messi. We regularly update the FIFA 16 Ultimate Team hack tool and ensure that it is working when you login to the website. Only a few are so lucky to get IF player or incredible player like Cristiano Ronaldo. This is Just More than the Coins those Sparkling Eyes and Emotions when the Football Kisses the Corner of the Net With Messi Ronaldo Benzema’s Enigmatic Footworks. 93 which do not let the EA understand that you’ve only created some coins and factors but nevertheless for security reasons we advocate for no more than use needs to be thrice a day as you never need to get banned and do not need to spent money too but need coins and factors therefore simply follow the directions below and perform the game superbly with your greatest team That is all we need. there is no need to pay anything for using this program. Recently we are working for a FIFA 16 Coin Generator Online. One of the latest features is the anti ban system to protect your account. Let me start. they’ve ensured all the effort has been completed. The game is the first in the FIFA series to include female players. No fees. Let me ask you one question: Did you ever check the leaderboard of FIFA Ultimate Team before the actual release of the game? Normally it should be impossible to have millions of FIFA Coins. Fifa 16 Points from Below Linked Online generator. to allow our friends and visitors to obtain Free FIFA 16 Coins easily and get all the upgrades and players.
fifa 16 ios coins xbox
fifa 16 hack forums
fifa 16 ultimate team coins android
hack fifa 16 coins no survey
fifa 16 hack app
fifa 16 coins egypt
fifa 16 coins bot
fifa 16 unlimited draft tokens
fifa 16 coins utfifa
fifa 16 money cheat ultimate team xbox 360
fifa 16 ultimate team coins free ps3
fifa 16 coins ps4 sms
fifa 16 coins to sell
fifa 16 ultimate team coins accounts
fifa 16 coins price
fifa 16 coins xbox one
fifa 16 coins android
fifa 16 buy coins ps3
fifa 16 unlimited apk
fifa 16 android hack 6.108.5
fifa 16 xbox 360 coins sms
fifa 16 hack ifunbox
fifa 16 free coins legit
fifa 16 money cheat career mode
fifa 16 generator coins value
Fifa 16 Hack Tool No Human Verification. Fifa 16 Hack Coins HackFifa 16 Ultimate Team Coins Generator Ios. Fifa 16 Hack Ios No SurveyFifa 16 Coins Method. Hack Fifa 16 Ios No SurveyFifa 16 Hack Free Download. Fifa 16 Coins Buy OnlineFifa 16 Hacks For Xbox One. Cheat Fifa 16 Youtube
fifa 16 coins really cheap
fifa 16 card generator
fifa 16 android hack no root
fifa 16 hacks ps3 no survey
fifa 16 hack unlimited coins
fifa 16 free coins no survey online
fifa 16 unlimited money
fifa 16 ultimate team coins xbox one
fifa 16 coins vbarrack
fifa 16 ultimate team coins ps4
fifa 16 android hack download
fifa 16 hack coins value
fifa 16 coins kopen
fifa 16 coins 360
fifa 16 coins pc games
fifa 16 ultimate team coins generator
cheat fifa 16 matches
fifa 16 cheats and tricks
fifa 16 ultimate team hack
fifa 16 coins pc 14
fifa 16 coins xbox one free
fifa 16 hacks jailbreak
fifa 16 coins 100k for ВЈ5
fifa 16 ios coins value
fifa 16 free coins legit
Fifa 16 Coins Origin. Fifa 16 Android Hack RootFifa 16 Ultimate Team Hack. Hack Fifa 16 CydiaFifa 16 Coins Ps4. Fifa 16 Cheats To Get CoinsFifa 16 Coins Comfort Trade Xbox One. Fifa 16 Cheats For AndroidFifa 16 Buy Coins Xbox One. Fifa 16 Coins Duplicator

Spam control