Use “alias” in Linux

In file “~/.bash_profile“, we can use alias to define keyword shorter to run app faster 🙂

Example: In server has been installed redis. To run redis-server we must run command “/opt/redis/latest/bin/redis-server”. We can use alias in “~/.bash_profile“:

alias redis-server="/opt/redis/latest/bin/redis-server"

And with redis-cli we must run command: “/opt/redis/latest/bin/redis-cli”. We can use alias:

alias redis-cli="/opt/redis/latest/bin/redis-cli"

And now, we can type redis-server or redis-cli in terminal instead of long command: “/opt/redis/latest/bin/redis-server” and “/opt/redis/latest/bin/redis-cli”.

 

When we added alias to “~/.bash_profile“, we can reload “~/.bash_profile” by the way:

. ~/.bash_profile

 

Change the Command-Line Prompt Colour in the Ubuntu/Linux Terminal

First, open file bashrc

gedit ~/.bashrc

Find line has text: if [ “$color_prompt” = yes ]; then

Copy context in if clause and paste to else clause

Save, close and reopen terminal. 🙂

Optional information:

Black 0;30 – Dark Gray 1;30 – Blue 0;34 – Light Blue 1;34 – Green 0;32 – Light Green1;32 – Cyan 0;36 – Light Cyan 1;36 – Red 0;31 – Light Red 1;31 – Purple 0;35 – Light Purple 1;35 – Brown 0;33 – Yellow 1;33 – Light Gray 0;37 – White 1;37

 

[Linux] Using the Vim editor

Commands that switch the editor to insert mode

  • a will append: it moves the cursor one position to the right before switching to insert mode
  • i will insert
  • o will insert a blank line under the current cursor position and move the cursor to that line.
  • Esc key switches back to command mode.

Pressing the Esc key switches back to command mode. If you’re not sure what mode you’re in because you use a really old version of vi that doesn’t display an “INSERT” message, type Esc and you’ll be sure to return to command mode. It is possible that the system gives a little alert when you are already in command mode when hitting Esc, by beeping or giving a visual bell (a flash on the screen). This is normal behavior.

Basic operations

These are some popular vi commands:

  • n dd will delete n lines starting from the current cursor position.
  • n dw will delete n words at the right side of the cursor.
  • x will delete the character on which the cursor is positioned
  • :n moves to line n of the file.
  • :w will save (write) the file
  • :q will exit the editor.
  • :q! forces the exit when you want to quit a file containing unsaved changes.
  • :wq will save and exit
  • :w newfile will save the text to newfile.
  • :wq! overrides read-only permission (if you have the permission to override permissions, for instance when you are using the root account.
  • /astring will search the string in the file and position the cursor on the first match below its position.
  • / will perform the same search again, moving the cursor to the next match.
  • :1, $s/word/anotherword/g will replace word with anotherword throughout the file.
  • yy will copy a block of text.
  • n p will paste it n times.
  • :recover will recover a file after an unexpected interruption.

Refer: http://www.tldp.org/LDP/intro-linux/html/sect_06_02.html

[Docker] Error: Can’t not access internet from container in Ubuntu 14.04

When I use Docker, I create container from image (Ex: Ubuntu:14.04) and ssh to this container by command:

docker run -it <image_id> bash

When I ssh to container, I used command ping google.com 

but I get error:  ping: unknown host google.com

To fix it, I have 2 solutions, but first, you must get DNS of your machine by command

nm-tool 

Result in my machine:

DNS: 192.168.30.29
DNS: 192.168.30.66

=> I’ll use DNS: 192.168.30.29

1. Solution 1

– Go to file sudo nano /etc/docker/daemon.json and add your DNS to this file

{
    "dns": ["192.168.30.29", "8.8.8.8", "8.8.4.4"]
}

Save it and restart docker by command: sudo service docker restart

2. Solution 2

solution 1- Go to file sudo nano /etc/default/docker, uncomment and add your DNS to this row:

DOCKER_OPTS="--dns 192.168.30.29 --dns 8.8.8.8 --dns 8.8.4.4 --ip-masq=true"

Save it and restart docker by command: sudo service docker restart

If when restart, you get error:

docker stop/waiting
start: Job failed to start

or error:

stop: Unknown instance: 
start: Job failed to start

– You shoud go to file sudo nano /etc/default/docker, and comment row

DOCKER_OPTS="--dns 192.168.30.29 --dns 8.8.8.8 --dns 8.8.4.4 --ip-masq=true"

and try again with solution 1.

==> After you try adding DNS successfully, you can ssh to container and run

ping google.com once again. And this is my result after try fixing with solution 1

root@2beb109bc7b3:~# ping google.com
PING google.com (113.171.239.123) 56(84) bytes of data.
64 bytes from static.vnpt.vn (113.171.239.123): icmp_seq=1 ttl=56 time=1.06 ms
64 bytes from static.vnpt.vn (113.171.239.123): icmp_seq=2 ttl=56 time=1.51 ms
64 bytes from static.vnpt.vn (113.171.239.123): icmp_seq=3 ttl=56 time=2.32 ms
64 bytes from static.vnpt.vn (113.171.239.123): icmp_seq=4 ttl=56 time=1.19 ms
64 bytes from static.vnpt.vn (113.171.239.123): icmp_seq=5 ttl=56 time=1.55 ms
.....

That’s all. Thank you for reading. 🙂

[Docker] Error Cannot connect to the Docker daemon. Is the docker daemon running on this host?

In Ubuntu, when I install Docker successfully, I try running with command:

docker images #show all images in local

but it has error

Cannot connect to the Docker daemon. Is the docker daemon running on 
this host?

because it doesn’t have permission of root. I can run it by command

sudo docker images

Another way, we can config it to needn’t use sudo

  • Step 1: go to /var/run

    cd /var/run
  • Step 2: Add permission for file docker.sock
    sudo chmod -R 776 docker.sock
    

And now, we can use command docker images for shorter code

 

Access remote server with local phpMyAdmin in Ubuntu

1

Default, the login page of phpmyadmin have only username & password. If you want to add some remote server you can follow by some steps:

  1. Find file “/etc/phpmyadmin/config.inc.php”
  2. Find row “/* Advance to next server for rest of config */” and add some configs below “$i++;”

/* Advance to next server for rest of config */
$i++;

/* some additional configs  */
$cfg[‘Servers’][$i][‘host’] = ‘52.69.150.47’;
$cfg[‘Servers’][$i][‘user’] = ‘mery_box’;
$cfg[‘Servers’][$i][‘password’] = ‘TewKszmceNQA’;
$cfg[‘Servers’][$i][‘auth_type’] = ‘config’;

And the result:

1

Can’t show group chat Skype in Ubuntu 14.04

I installed Skype in Ubuntu 14.04,  but when I logged in to Skype, I only show and chat with my friends and can’t show any groups, I fixed it by the way:

Open chat box with any my friend and type:

/dumpmsnp   #show details about your connection

And I showed log:

System: MSNP: Connection Data:
 * Status: LoggedOut

Ref:It’s LoggedOut   => It is problem

To solve it, type:

/msnp24

Then log out and restart Skype. After that, type again:

/dumpmsnp 

And I see:

System: MSNP: Connection Data (MSNP24):
 * Status: LoggedIn

And I also see all my groups in Skype, and the issue was solved.

Ref:  https://community.skype.com/t5/Mac-archive/New-chat-groups-not-showing-up-in-client/td-p/3206434

FIX BRIGHTNESS CONTROL NOT WORKING FOR UBUNTU 14.04

On my Acer Aspire with Ubuntu 14.04, using function key to change the brighness did not yield any results. Brighness can not change. My laptop uses cards:  Nvidia Graphics and Intel graphics.

FIND VIDEO/GRAPHICS CARD IN UBUNTU

Run the command below in terminal to know what video card is used for the backlight/brightness:

ls /sys/class/backlight/

get_graphic_card_in_use

As you can see, the output for me is  intel_backlight. An indicator that the graphics card in use is Intel.

If your graphics card is Intel, you can proceed with the fix below:

FIX BRIGHNESS CONTROL ISSUE WITH INTEL CARD IN UBUNTU 14.04

Open a terminal and create the following configuration file, if it does not exist:

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

Now we need to edit this file. You can use any editor be it a terminal one or graphical.

sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf

Add the following lines to this file:

Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"
EndSection

Save it. Log out and log in back. The brightness control should be working through function keys now.

 

Original post: http://itsfoss.com/fix-brightness-ubuntu-1310/