Ubuntu Linux - Connect Postgresql from Psql and also PGadmin Remotely

 Step 1 :

> sudo su

> vi /etc/postgresql/10/main/postgresql.conf

#listen_addresses = 'localhost'

to 

listen_addresses = '*'

>vi /etc/postgresql/10/main/pg_hba.conf
# IPv4 local connections:
host    all             all    127.0.0.1/32  md5

to
host    all             all   0.0.0.0/0   md5


>sudo ufw allow 5432/tcp
>sudo systemctl restart postgresql


     
>psql -h localhost -d databasename -U userrolename
    ...enterpasswordfor-userrolename

Security : Java PHP encryption decryption for AES-128-CTR or AES/CTR/NoPadding

 Java

package com.security;

import java.util.Base64;

import javax.crypto.Cipher;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

/**

 * @author drvijay

 * @date 13-0ct-2021

 */

public class EncryptDecrypt

{

private static String encrypt ( String data, String cipherType, String key, String iv )

{

String encrypted = "";

try

{

Cipher encryptionCipher = Cipher.getInstance ( cipherType );

IvParameterSpec ivv = new IvParameterSpec ( iv.getBytes ( "UTF-8" ), 0, encryptionCipher.getBlockSize () );

encryptionCipher.init ( Cipher.ENCRYPT_MODE, new SecretKeySpec ( key.getBytes (), "AES" ), ivv );

// encrypt

byte [] cipherText = encryptionCipher.doFinal ( data.getBytes () );

encrypted = new String ( Base64.getEncoder ().encode ( cipherText ) );

}

catch ( Exception e )

{

throw new IllegalStateException ( e );

}

return encrypted;

}

private static String decrypt ( String encryptData, String cipherType, String key, String iv )

{

String decrypted = "";

try

{

Cipher decryptionCipher = Cipher.getInstance ( cipherType );

IvParameterSpec ivv = new IvParameterSpec ( iv.getBytes ( "UTF-8" ), 0, decryptionCipher.getBlockSize () );

SecretKeySpec secretKeySpec = new SecretKeySpec ( key.getBytes (), "AES" );

decryptionCipher.init ( Cipher.DECRYPT_MODE, secretKeySpec, ivv );

// decrypt

byte [] finalCipherText = decryptionCipher.doFinal ( Base64.getDecoder ().decode ( encryptData ) );

// converting to string

String finalDecryptedValue = new String ( finalCipherText );

decrypted = finalDecryptedValue;

}

catch ( Exception e )

{

throw new IllegalStateException ( e );

}

return decrypted;

}

public static void main ( String [] args )

{

String cipherType = "AES/CTR/NoPadding";

String valueToEncrypt = "hello, vijay";

String key = "0123456789abcdef";

String iv = "2208250639374785";

String encrypted = encrypt ( valueToEncrypt, cipherType, key, iv );

String decrypted = decrypt ( encrypted, cipherType, key, iv );

//System.out.println(Base64.getDecoder ().decode ( "ycbnIE8vn2lTUi/9F/FEa+5v86qzOU09yjdxfGDc8wA=" ));

// END OF ENCODE CODE

System.out.println ( "encrypted and saved as Base64 : " + encrypted );

System.out.println ( "decrypted from Base64->aes128 : " + decrypted );

// END OF DECRYPT CODE

}

}

PHP code

<!DOCTYPE html>

<html>

<body>

<?php

$simple_string = "hello, vijay";

echo ($simple_string .'<br/>');

        $ciphering = 'AES-128-CTR';

        $iv_length = openssl_cipher_iv_length($ciphering);

        $options = 0;

        // Non-NULL Initialization Vector for encryption

        $iv = '2208250639374785';

       

        $key = '0123456789abcdef';

                $encryption = openssl_encrypt($simple_string, $ciphering,

                    $key, $options, $iv); 

                    echo($encryption .'<br/>');

                    

                  $decryption=openssl_decrypt ($encryption, $ciphering,

                $key, $options, $iv);

                echo($decryption .'<br/>');

                

?>

</body>

</html>

output

hello, vijay
0iQoUVC/QZG3cM20
hello, vijay

Java to Do ImageMagick Call

 package com.product.zilly;

import java.io.File;

import java.util.Map;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * @author drvijay

 * @description img class

 * @version 1.0

 */

@SuppressWarnings ("all")

public class TestModules implements Constants

{

private static final Logger logger = LoggerFactory.getLogger ( TestModules.class );

public static void main ( String args[] )

{

ImageHelper imageHelper = new ImageHelper ();

String renditionPath = "/home/drvijay/images"; 

String rendtionPathCategory = "/home/drvijay/images"; 

String startingMainPath = renditionPath + PATH_SEPARATOR + SkuRendition.main;

String startingCategoryMainPath = rendtionPathCategory + PATH_SEPARATOR + SkuRendition.main; // for category images main path

imageHelper.loadSkuImageProperties ();

boolean imageOverride = false; 

File rotated = null;

File file = new File ( startingMainPath + PATH_SEPARATOR + "sample.png" );

if ( file.isFile () && file.exists () )

{

Map <SkuRendition, Map <Resolution, DimInfo>> dimensions = imageHelper.getAllDimensions ();

logger.debug ( dimensions.toString () );

for ( SkuRendition skuRendition : dimensions.keySet () )

{

try

{

Map <Resolution, DimInfo> resolutions = dimensions.get ( skuRendition );

for ( Resolution resolution : resolutions.keySet () )

{

DimInfo dimInfo = resolutions.get ( resolution );

File isExist = new File ( renditionPath + PATH_SEPARATOR + skuRendition.name () + PATH_SEPARATOR + resolution.name () + UNDER_SCORE + file.getName () );

if ( ( imageOverride && isExist.isFile () && isExist.exists () ) || ( !isExist.isFile () && !isExist.exists () ) )

{

rotated = imageHelper.processImage ( file, imageHelper.getOutputDir ( renditionPath, skuRendition.name () ), dimInfo, resolution.name () );

logger.debug ( "Generated : " + rotated.getAbsolutePath () );

}

}

}

catch ( Exception e )

{

logger.error ( "Error : " + e );

}

finally

{

/*

* if ( rotated != null )

* {

* rotated.delete ();

* }

*/

}

}

}

}

}

//Iamge Process

public File processImage ( File inFile, File outputDir, DimInfo dimInfo, String resolution ) throws Exception

{

String fileName = resolution + UNDER_SCORE + inFile.getName ();

// String fileNameWithOutExt = FilenameUtils.removeExtension(fileName);

// String fileNameExt = FilenameUtils.getExtension ( fileName );

// check for windows and set the image magick home manually to avoid error.

String OS = System.getProperty ( "os.name" ).toLowerCase ();

if ( ( OS.indexOf ( "win" ) >= 0 ) )

{

// linux - "/usr/lib/mime/packages/imagemagick-6.q16";

String myPath = "C:/Program Files/ImageMagick-6.9.2-Q16"; // globalMaster.getSystemProperties ().get ( KEY_PATH_HOME_IMAGE_MAGICK ).getValue ();

ProcessStarter.setGlobalSearchPath ( myPath );

}

ConvertCmd convert = new ConvertCmd ();

IMOperation operation = new IMOperation ();

String input = inFile.getAbsolutePath ();

int tmbWidth = dimInfo.getWidth ();

int tmbHeight = dimInfo.getHeight ();

operation.addImage ( input );

operation.gravity ( LocalProperties.getPropertyValue ( "render.image.gravity" ) );

operation.thumbnail ( tmbHeight, tmbWidth );

operation.units ( LocalProperties.getPropertyValue ( "render.image.units" ) );

operation.density ( Integer.parseInt ( LocalProperties.getPropertyValue ( "render.image.density" ) ) );

operation.strip ();

operation.interlace ( LocalProperties.getPropertyValue ( "render.image.interlace" ) );

operation.gaussianBlur ( Double.parseDouble ( LocalProperties.getPropertyValue ( "render.image.gaussian.blur" ) ) );

operation.quality ( Double.parseDouble ( LocalProperties.getPropertyValue ( "render.image.quality" ) ) );

File retVal = new File ( outputDir, fileName );

operation.addImage ( retVal.getAbsolutePath () );

convert.run ( operation );

logger.debug ( "Preview file: " + retVal.getAbsolutePath () );

return retVal;

}

Install Latest ImageMagick to support PNG, JPG convertions

 #These are the steps required in order to Install ImageMagick with JPG, PNG and TIFF delegates.

sudo apt-get update 

#Install Build-Essential in order to configure and make the final Install

sudo apt-get install build-essential 

#libjpg62-dev required in order to work with basic JPG files

sudo apt-get install -y libjpeg62-dev 

#libtiff-dev is required in order to work with TIFF file format

sudo apt-get install -y libtiff-dev 

#libpng-dev required in order to work with basic PNG files

sudo apt-get install -y libpng-dev

#Download ImageMagick

wget https://www.imagemagick.org/download/ImageMagick.tar.gz 

#Untar Imagemagick

tar xvzf ImageMagick.tar.gz 

#Access the working directory

cd ImageMagick-[version_number] 

#Configure and make sure to disable the "shared" option

./configure --disable-shared

#Make

sudo make

#Install

sudo make install

#Final Check

sudo make check

Eclipse - Python Import Libraries or Error issues fixes

 step 1) Removing the interpreter, auto configuring it again

step 2) Window - Preferences - PyDev - Interpreters - Python Interpreter Go to the Forced builtins tab Click on New... Type the name of the module (tensorflow in my case) and click OK

step 3) Right click in the project explorer on whichever module is giving errors. Go to PyDev->Code analysis.

Python - ImportError: cannot import name 'signature' from 'sklearn.utils.fixes'

 Please install funcsigs directly using

pip install funcsigs

and use from funcsigs import signature instead.

#ex:

#from sklearn.utils.fixes import signature

from funcsigs import signature

-- enjoy

How to install Gnome Extensions

 Extract the downloaded file. Copy the folder to ~/.local/share/gnome-shell/extensions directory. Go to your Home directory and press Crl+H to show hidden folders. Locate .local folder here and from there, you can find your path till extensions directory. 

Once you have the files copied in the correct directory, go inside it and open metadata.json file. Look for the value of uuid. 

Make sure that the name of the extension’s folder is same as the value of uuid in the metadata.json file. If not, rename the directory to the value of this uuid.

Name of extension folder should be the same as uuid

Almost there! Now restart GNOME Shell. Press Alt+F2 and enter r to restart GNOME Shell.

Restart GNOME Shell

Restart GNOME Tweaks tool as well. You should see the manually installed GNOME extension in the Tweak tool now. You can configure or enable the newly installed extension here.

And that’s all you need to know about installing GNOME Shell Extensions.

Remove GNOME Shell Extensions

It is totally understandable that you might want to remove an installed GNOME Shell Extension.

If you installed it via a web browser, you can go to the installed extensions section on GNOME website and remove it from there (as shown in an earlier picture).

If you installed it manually, you can remove it by deleting the extension files from ~/.local/share/gnome-shell/extensions directory.

Ubuntu KAZAM Screencast Recorder Audio Problem - FIX

1. Install Kazam 

    sudo apt install kazam

 2. modify this file:

/usr/lib/python3/dist-packages/kazam/pulseaudio/pulseaudio.py

and replace

time.clock()

with

time.perf_counter()

OR SIMPLE CLI COMMAND

sudo sed "s/time.clock()/time.perf_counter()/g" -i /usr/lib/python3/dist-packages/kazam/pulseaudio/pulseaudio.py

3. Open Kazam, Go to File -> Preferences. General

    Speakers -> SELECT from the list like 

                   Monitor of Built-in Audio ...







ENJOY





How to Host Flask Applications on Namecheap cPanel

Very good. 

1. Follow the link, 

 https://dev.to/lordghostx/how-to-host-flask-applications-on-namecheap-cpanel-299b

2. In Execute Python Script 

-m pip install --upgrade pip

-m pip install -r requirements.txt

Restart the server for app.py changes.

Joomla Wordpress - Friendly URL not working

1. Open Cpanel -> File Manager
    Top right corner ->Settings or find settings 
    Show Hidden Files. 

2. Goto public_html folder/.htaccess
paste the below block, save & close.

<IfModule mod_rewrite.c>
RewriteEngine On
# Removes index.php from ExpressionEngine URLs
RewriteCond $1 !\.(gif|jpe?g|png)$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php/$1 [L]
</IfModule>

3. Now goto global configuration ->joomla -> turn on Friend URL redirection.