Google Sheet Sigle column No Duplicate Data Validation

 Here the example is given for column A:

=COUNTIF($A$2:$A711,$A13)<2

How to Install SQLite driver for your PHP version in Ubuntu

Log in to your web server via SSH and run the following command:

sudo apt-get install php-sqlite3

If the above command does not work, you can try the PHP version-specific instructions below:

For PHP5, use

sudo apt-get install php5-sqlite

For PHP7.0, use

sudo apt-get install php7.0-sqlite

For PHP7.1, use

sudo apt-get install php7.1-sqlite

For PHP7.2, use

sudo apt-get install php7.2-sqlite

For PHP7.3, use

sudo apt-get install php7.3-sqlite

For PHP7.4, use

Then

Restart Apache

sudo service apache2 restart

Restart Nginx

sudo service nginx restart

How to generate SSH keys in Mac OS

To generate SSH keys in Mac OS X, follow these steps:

1. Enter the following command in the Terminal window.ssh-keygen -t rsa
This starts the key generation process. When you execute this command, the ssh-keygen utility prompts you to indicate where to store the key.

2. Press the ENTER key to accept the default location. The ssh-keygen utility prompts you for a passphrase.

3. Type in a passphrase. You can also hit the ENTER key to accept the default (no passphrase). However, this is not recommended.
Please note that you will need to enter the passphrase a second time to continue.

After you confirm the passphrase, the system generates the key pair.

Your identification has been saved in /Users/user/.ssh/id_rsa.

Your public key has been saved in /Users/user/.ssh/id_rsa.pub.

The key fingerprint is:

ae:89:72:0b:85:da:5a:f4:7c:1f:c2:43:fd:c6:44:38 user@mymac.local

The key's randomart image is:

+--[ RSA 2048]----+

|                 |

|         .       |

|        E .      |

|   .   . o       |

|  o . . S .      |

| + + o . +       |

|. + o = o +      |

| o...o * o       |

|.  oo.o .        |

+-----------------+

Your private key is saved to the id_rsa file in the .ssh directory and is used to verify the public key you use belongs to the same cloud server. It's important to never share your private key with anyone, it is equivalent of your password!

Your public key is saved to the id_rsa.pub file and it is the key you'll upload to our cloud service. You can save this key to the clipboard by running this:

pbcopy < ~/.ssh/id_rsa.pub

or

cat ~/.ssh/id_rsa.pub

How to retry delivery of Postfix mail in queue?

 postsuper -r ALL && postqueue -f

Zip Extension for PHP 7.2 on CentOS 8

 yum install php-pecl-zip

apachectl restart

Install imap extension on PHP 7.x or Higher in CentOS 8

yum update -y 

yum install -y https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm 

yum install -y https://rpms.remirepo.net/enterprise/remi-release-7.rpm 

yum install -y php80-php-imap 

cp /opt/remi/php80/root/usr/lib64/php/modules/imap.so /usr/lib64/php/modules/ /bin/echo 'extension="imap.so"' > /etc/php.d/40-imap.ini 

systemctl restart php-fpm

Install PHP-mbstring on CentOS 8 for PHP 7.4

dnf install php-mbstring

dnf install https://rpms.remirepo.net/enterprise/remi-release-8.rpm

dnf install php74-php-mbstring