jq command in Linux

 How to access the {"field-name":"cskmetro"}

echo "{\"field-name\":\"cskmetro\"}" |jq -r '."field-name"'

will give the field value

cskmetro

Linux Kernel Compilation

 Step 1: Install Required Packages

Install additional packages before building a kernel. To do so, run this command:

sudo apt-get install git fakeroot build-essential ncurses-dev xz-utils libssl-dev bc flex libelf-dev bison


Step 2:

Download the Kernel source code from kernel.org, Extract the tar file

Install linux-headers for the base kernel version use following command to know the base kernel version 'uname -a'


Step3 :


Goto the Extracted directory/folder

run following command

make menuconfig


then save the configurationg and click exit


Step 4 :


Run the following command for compiling kernel

make

Step 5 :

Install kernel modules and kernel

make modules_install
make install

 

Step 6:

 

If amd based CPU in the machine

  sudo apt-get install firmware-amd-graphics

Jupyter installation

 

Step 1:

upgrade the pip3

apt-get install python3-pip

sudo pip3 install --upgrade pip 

Step 2:

Create virtual environment

sudo pip3 install virtualenv

pip3 install virtualenv

mkdir demo
cd demo
virtualenv mynotebookenv
source mynotebookenv/bin/activate 

Step 3:

install the jupyter 

pip install jupyter

jupyter notebook

JAVA Path and JAVA_HOME Path Setting in Linux

 

1. Open the Terminal

2. Prepend sudo if logged in as not-privileged user, ie. sudo nano

3. nano /etc/profile

4. Press 'i' to get in insert mode

5. add following :

   export JAVA_HOME="path that you found"
   
   export PATH=$JAVA_HOME/bin:$PATH
   

6. logout and login again, reboot, or use source /etc/profile to apply changes immediately in your current shell

Running Simple Web Server on Python 2 and Python 3

 

Running Simple Web Server on Python 2

python -m SimpleHTTPServer 8000

Running Simple Web Server on Python 3

python -m http.server 8000

Log rotate error :error: skipping "log file name or path of the file" because parent directory has insecure permissions (It's world writable or writable by group which is not "root") Set "su" directive in config file to tell logrotate which user/group should be used for rotation.

 Error Description:

error: skipping "<log file name>" because parent directory has insecure permissions (It's world writable or writable by group which is not "root") Set "su" directive in config file to tell logrotate which user/group should be used for rotation.

Answer

su <user> <group>

Root Terminal Enabling in Linux

 

1.Open the /etc/passwd file

 change the following line 

root:x:0:0:root:/root:/usr/sbin/nologin

to

root:x:0:0:root:/root:/bin/bash

2.Issue the following command in terminal

chmodg+rx /usr/bin/gnome-terminal

How to run the simple http server

1.open the terminal in linux
2.go to the current folder you want share and issue following on terminal

python -m SimpleHTTPServer

Merging files - line by line

paste file1 file2 > file3