Linux+ exam 2
screen reader
Accessibility feature for users with eyesight problems, which reads text aloud.
xhost + hostname
Adds hostname to X server access control list
BROWSER
Contains the path to the web browser
LS_COLORS
Defines color codes used to optionally add color to ls command output
LANG
Defines the language character set
LightDM
Display manager that aims to be lightweight; generally on Ubuntu
set
Displays options related to bash operation
test
Evaluate a conditional expression test expr [ expr ] [[ expr ]]
~/.my.cnf
File allows user to access mysql database without credentials. Located in users home directory. [client] user= <username> password= <password>
GDM
GNOME Display Manager
X
GUI system for our desktop startx; begins process; calls the xinit xinit ; reads info in the .xinit and .xinitrc for displaying other environmental variables *system level xinitrc: /etc/X11/xinit/xinitrc *also user level: ~/.xinitrc
~/.bash_login
If .bash_profile exists, then Bash will not read this hidden file. Otherwise, whatever is contained inside will run upon user login and the user's shell environment loading
KDM
KDE Display Manager
DISPLAY
Names the display if running a graphical environment
EDITOR
Names the preferred text editor
PAGER
Names the program used for paging output
SHELL
Names the shell program
PWD
Prints the current working directory. The pwd command produces the same information
PATH
Provides a colon separated list of directories you searched for when entering a name of an executable program
xhost - hostname
Removes hostname from X server access control list
SHELLOPTS
Shell options set with the set command
HOSTNAME
Shows computer hostname
HOME
Shows pathname of home directory
Shows the path to the current user's mailbox
OLD_PWD
Shows the previous working directory
PS1
Stands for prompt string 1(PS1) and defines content of your shell prompt
TERM
The name of the terminal type
TZ
The timezone. Most Unix-like/Linux systems maintain an internal clock set to Coordinated Universal Time (UTC) and displays the local time
UID
User ID of current user
USER
Your username
xhost +
access is granted to everyone, even if they aren't on the list, to the X server
Sticky keys
accessibility feature for users unable to press multiple keys at once
mysql -uroot -p
accessing mysql with credentials
~/.bashrc
anything contained in this hidden file will run upon the user logging in, shell or no shell ** .bash.bashrc for Debian/Ubuntu
~/.bash_profile
anything contained in this hidden file will run when the user logs in and their shell environment loads
~/.bash_logout
anything contained in this hidden file will run when user logs out
XDM
bare bones X windows Display manager
WHERE
clause is used to filter the results from a SELECT, INSERT, UPDATE, or DELETE statement
lightdm config
configuration for this display manager: /usr/share/lightdm/lightdm.conf.d <is overriden by> /etc/lightdm/lightdm.conf.d/*.conf <is overriden by> /etc/lightdm/lightdm.conf
xdpyinfo
display information about an X server
fc-cache
font cache files -r; removal of font cache -f; rebuild the font cache
Zoom
for users with sight impairment
for
for { condition } do command1 command2 .... ... commandN done
seq
generates and prints a range of numbers
if
if [ condition ] then <commands> fi
bounce keys
ignores fast duplicate key presses
Large text
increases size for visibility
modifier key
key that is used in conjunction with other keys; shift, ctl, other keys
fc-list
list available fonts for the system -v; verbose ** can pass font name in command :lang=<language> ; specify specific language
create database
make a new mysql database
create table
make a new table inside of a database
alias
makes it possible to launch any command or group of commands by entering a pre-set string
/etc/X11/xorg.conf
monitor and video settings file
\e[m\]
opens and closes the color prompt
xwininfo
pull information about various windows running in our system -id 0x3c00024 ; can pass an id -name "name" -root ; gives the root window info -children ; can see how many children -root -children -all ; will show everything on the system -events ; events that are being listened for -wm ; window manager information
/etc/skel
put files in this directory that will copy over to new user home directories
bash flag: \w
represents current working directory
bash flag: \h
represents hostname
bash flag: \u
represents user
INNER JOIN
return all rows from multiple tables where the join condition is met
LEFT JOIN
returns all rows from the LEFT-hand table specified in the ON condition and only those rows from the other table where the joined fields are equal
RIGHT JOIN
returns all rows from the RIGHT-hand table specified in the ON condition and only those rows from the other table where the joined fields are equal
/etc/init/rc-sysinit.conf
runlevel config file for ubuntu
xhost
server access control program for X provides the ability to run X commands on your local system
show-databases
show the existing mysql databases
describe
shows detailed information about a database table
bash flag: \j
shows number of running jobs
bash flag: \d
shows the date
bash flag: \$
shows the dollar sign if you are NOT root if running root, a hash# will be displayed
HISTFILESIZE
shows the number of lines in command line history
HISTSIZE
shows the number of lines of command history permitted for use in memory
show tables
shows the tables inside of a database
bash flag: \@
shows the time 12-hr AM/PM
bash flag: \t
shows the time 24-hr time
BASH_VERSION
shows the version of bash shell used
exec
specify a command to replace the shell. No new process will be created
use
specify a database to use
mysqldump -uroot -p
specify a mysql database to dump and redirect to a file
high contrast
switch to a higher contrast screen
/etc/profile.d
this directory contains application-specific startup files
/etc/profile
this file sets the environmental variables at startup of the bash shell
DROP DATABASE name;
to delete a mysql database
xhost -
turns on access control for X server access is restricted to only those listed
function
use to place frequently used commands or logic in a script and call it from another after sourcing
ON
used in a JOIN statement to combine different fields from different tables
GROUP BY
used in a SELECT statement to collect data across multiple records and group the results by one or more columns
ASC
used in sql statement to produce a ascending list
DESC
used in sql statement to produce a descending list
DELETE
used to delete a single or multiple records from a table in MySQL
unset
used to delete variables during program execution
INSERT INTO
used to insert a single record or multiple records into a table in MySQL
FROM
used to list the tables and any joins required for the query in MySQL
env
used to print a list of the current environment variables
SELECT
used to retrieve records from one or more tables in MySQL
export
used to set variables on a bash shell
ORDER BY
used to sort the records in your result set
AND
used to test two or more conditions in a SELECT, INSERT, UPDATE, or DELETE statement
UPDATE
used to update existing records in a table in a MySQL database
while
while { condition } do command1 command2 .... ... commandN done
read
will take input from user and pass to a variable
