Posts by ServerOk

PrestaShop show comment in invoice

PrestaShop order comment in invoice

To show user comment in PrestaShop PDF invoice Edit file classes/pdf/HTMLTemplateInvoice.php

Inside function getContent(), find around line 161

Add below

In the same file, around line 333, find the $array variable, inside it, add

Edit file pdf/invoice.tpl


Add above

Back to PrestaShop […]

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PrestaShop show total product weight in PDF invoice

Show weight in prestashop invoice

To show total product weight in PrestaShop PDF invoice, edit file.

Inside function getContent(), on line 166, find

Replace with

On around line 332, find

Above $data line, add

Inside the array, add

Now we need to edit the PDF template file.

Inside the file, find

Add […]

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PrestaShop add customer email to invoice

PrestaShop show customer email

PrestaShop PDF invoice won’t show customer email address by default for some strange reason. To show the email address in the Invoice, we need to manually modify PrestaShop files. This instruction is tested on PrestaShop version To show customer email address in PrestaShop PDF invoice, edit file

On line 329, find

Inside […]

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How to verify rDNS (reverse DNS)/PTR Record

check rdns with nslookup

RDNS (Reverse DNS) resolves an IP address to a domain name. To find rDNS for an IP address, you can use the command nslookup.

In the above screenshot, IP address have reverse DNS set to You also need to verify the hostname points to IP address. Many server providers check this before […]

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postfix smtp Must issue a STARTTLS command first

postfix mail server

When sending an email to a server, mail bounced with the following error message.

To fix the error, first enabled debug in postfix for the Remote-MTA, for this, edit file

Add the following lines. You need to remove these lines after debug is completed or your log file will get larger with debug […]

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How to install Docker on CentOS 8


RHEL replaced Docker on RHEL 8 (CentOS 8) with podman. To install Docker on CentOS, you can do the fallowing steps. Install yum-utils

Add Docker repository

Install Docker with

Enable docker to start on boot

Start docker

Check the status of the docker

Back to docker […]

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dmidecode is a tool for dumping a computer’s DMI (SMBIOS ) table contents in a human-readable format. This table contains a description of the system’s hardware components, as well as other useful pieces of information such as serial numbers and BIOS revision. Thanks to this table, you can retrieve this information without having to probe […]

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How to find RAM details in Linux


To find RAM memory details (model number/manufacturer) in Linux, you can use the command

To show only model numbers, run

Once you find the Part Number, you can search in google for the part number to see more details about the RAM. On Ubuntu/Debian, you can install dmidecode with the command

On […]

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