Monday, July 31, 2023

Go (golang) not export fields of a struct when Unmarshal to json object


typedef MyData struct {

    Data            string    `json:"data"`   

    FieldName   *int64   `json:"-"` 


Adding the `json:"-"` will make the Unmarshal command disregard this field

Saturday, July 22, 2023

Cleaning and resizing VM VirtualBox VDI Virtual Machine Disk

 You have to do the following steps:

Run defrag in the guest (Windows only)
Nullify free space:

With a Linux Guest run this:

dd if=/dev/zero of=/var/tmp/bigemptyfile bs=4096k ; rm /var/tmp/bigemptyfile

telinit 1
mount -o remount,ro /dev/sda1
zerofree -v /dev/sda1
With a Windows Guest, download SDelete from Sysinternals and run this:

sdelete.exe c: -z
(replace C: with the drive letter of the VDI)

Shutdown the guest VM

Now run VBoxManage's modifymedium command with the --compact option:

With a Linux Host run this:

vboxmanage modifymedium --compact /path/to/thedisk.vdi
With a Windows Host run this:

VBoxManage.exe modifymedium --compact c:\path\to\thedisk.vdi
With a Mac Host run this:

VBoxManage modifymedium --compact /path/to/thedisk.vdi
This reduces the vdi size.

Thursday, May 25, 2023

Some notes about caddy webserver installation on Linux



sudo apt update

sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https

curl -1sLf '' | sudo tee /etc/apt/trusted.gpg.d/caddy-stable.asc

curl -1sLf '' | sudo tee /etc/apt/sources.list.d/caddy-stable.list

sudo apt update

sudo apt install caddy

# the code sits in /var/www

# create link to the local directory

ln -s /var/www/ /home/xxx/myprojects/web

# set the user to be xxx and the group caddy

sudo chown -R xxx:caddy ./www  

# add us to caddy groups

sudo usermod -a -G caddy xxx

sudo usermod -a -G www-data xxx

Install php-fpm

sudo apt install php-cli php-fpm php-mysql php-mbstring php-curl

configure caddy with php

sudo nano /etc/php/8.1/fpm/pool.d/www.conf

#change users to caddy (user, group, listen.owner,

#take the socket name: listen = /run/php/php8.1-fpm.sock

nano php.ini # set E_ALL view all errors

sudo systemctl restart php8.1-fpm

#set socket in Caddyfile: php_fastcgi unix//run/php/php8.1-fpm.sock

sudo service caddy stop && sudo service caddy start


Caddyfile {
#:80 {
tls /var/www/fullchain.pem /var/www/privkey.pem

# Set this path to your site's directory.
root * /var/www/
php_fastcgi unix//run/php/php7.4-fpm.sock

# Enable the static file server.
# file_server
rewrite /symbol/* s.php?s={path}
# rewrite /symbol/ {
# r ^/(\w+)/?$
# to /symbol.php?symbol={1}
# }

encode gzip

log {
output file /var/log/caddy/ {
roll_size 3MiB
roll_keep 5
roll_keep_for 48h
format console
# Another common task is to set up a reverse proxy:
# reverse_proxy localhost:8080

# Or serve a PHP site through php-fpm:
# php_fastcgi localhost:9000

#RewriteRule ^symbol/jscss/([^/]*)\.([^/]*)$ /jscss/$1.$2 [L] # no need for those since we used <base href="../" />
#RewriteRule ^symbol/images/([^/]*)\.([^/]*)$ /images/$1.$2 [L]
#rewrite /symbol/* / symbol.php?symbol={query}



I had the same problem whith my docker php-fpm and I fixed it by modifing parameters

 in these files: /usr/local/etc/php-fpm.d/www.conf /usr/local/etc/php-fpm.d/www.conf.default

The new parameters are :

pm = dynamic
pm.max_children = 25
pm.start_servers = 10
pm.min_spare_servers = 5
pm.max_spare_servers = 20
pm.max_requests = 500



- ADD how to enabled logs in PHP 


Monday, February 6, 2023

Linux terminal shell command line to show a list of just the files in the directory

Linux terminal shell command line to show a list of just the files in the directory

find . -type f

Wednesday, February 1, 2023

php8 COM Exception Type Mistmtach in paramater #0 when calling MS Word COM object SaveAs

php8 COM Exception Type Mistmtach in paramater #0 when calling MS Word COM object SaveAs

I saw this:


When calling $word->SaveAs($filename, 8);

You should change to $word->SaveAs($filename, new variant(8, VT_I4);



php 8 using ldap connectivity configuring php.ini and apache2.4

Got an error that ldap_connect is not a recognize function to use with apache 2.4, php 8 on windows

Here is a solution:


Enable extension=ldap in the php.ini


Copy .dll files from the php installation directory into the apache/bin installation directory

Please note, ldap_sort function was deprecated

Monday, January 16, 2023

Linux Ubuntu Changing the datair of mysql



datadir = /new/data/dir

mysqld --user=mysql --initialize

innodb_flush_log_at_trx_commit= 0
ssl=0 #  (5.7 community (self built) might not use SSL for cases. 8.0 always use ssl by default, might be slower)
innodb_doublewrite_pages=120 # (if doublewrite enabled for recent 8.0.x "on HDD")


sudo systemctl stop apparmor

sudo systemctl disable apparmor

sudo mysqldump --master-data=1 --flush-logs --single-transaction --routines --quick --all-databases > db20230116_1852.sql

CREATE USER 'XXXXX'@'%' IDENTIFIED WITH mysql_native_password BY 'XXXXXX';


Saturday, January 14, 2023

Monday, December 12, 2022

Enabling php error logging with caddy and php-fpm

How to enable php error logging with caddy and php-fpm

Inside the file:


Edit at the end:

php_admin_value[error_log] = /var/log/fpm-php.www.log
php_admin_flag[log_errors] = on

catch_workers_output = yes

Saturday, November 19, 2022

Script for creating html bookmarks file for Chrome to import

# Run this script on a file named urls.txt with all your URLs and pipe the output to an HTML file.
# Example: ./ > bookmarks.html

echo "<!DOCTYPE NETSCAPE-Bookmark-file-1>"
echo '<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">'
echo '<TITLE>Bookmarks</TITLE>'
echo '<H1>Bookmarks</H1>'
echo '<DL><p>'
  cat urls.txt |
  while read L; do
    echo -n '    <DT><A HREF="';
        echo ''"$L"'">'"$L"'</A>';
echo "</DL><p>"



Monday, July 11, 2022

Simple Using SQUID proxy server for Ubuntu 20.04

sudo apt install squid

sudo cp /etc/squid/squid.conf /etc/squid/squid.conf.original
sudo chmod a-w /etc/squid/squid.conf.original

sudo nano /etc/squid/squid.conf

inside squid.conf
http_port XXXXX
http_access allow all

sudo update-rc.d squid disable
sudo systemctl restart squid.service
sudo systemctl status squid
sudo systemctl disable squid
sudo systemctl stop squid

Saturday, June 25, 2022

The right way to use rsync

 rsync -avW -LK --progress ./from /to


Enable snap mysql-workbench to have access to the network

 sudo snap connect mysql-workbench-community:password-manager-service :password-manager-service

Saturday, March 19, 2022

Making sure my linux system does not wake up on suspend

Had this annoying problem in my linux Xubuntu 20.04 when putting on suspend the system then starts even though I put it in suspend and sleep.

Using acpitool to turn off wake-up from unnecessary devices.

But the problem the change is not permanent and does not survive a restart.

So I used cron @reboot to make sure it is always off:

@reboot acpitool -W 3 && acpitool -W 9 && acpitool -W 10 && acpitool -W 17 && acpitool -W 63 && acpitool -W 64 && acpitool -W 66 && acpitool -W 68 && acpitool -W 74


Thursday, March 17, 2022

Saturday, March 5, 2022

MySQL Test Timezone Script


SELECT @@global.time_zone, @@session.time_zone;

SET GLOBAL time_zone = 'Asia/Jerusalem';
SET SESSION time_zone = 'Asia/Jerusalem';

INSERT INTO tzt SET ts='2021-08-22 13:30:00', dt='2021-08-22 13:30:00';


SET GLOBAL time_zone = 'America/Sao_Paulo';
SET SESSION time_zone = 'America/Sao_Paulo';


Monday, January 10, 2022

Connecting to mysql with TLS 1.2 SSL encrypted connection

In order to be able to connect to MySQL remote server using encrypted connection overt TLS1.2 you will need a .pem certificate of CA.

 You can obtain the certificate here:


Read more here:

Here is a PHP sample for connection with SSL to MySQL encrypted connection on TLS1.2:

self::$mysqli = mysqli_init();
//self::$mysqli->options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, true);
self::$mysqli->ssl_set(NULL, NULL, "DigiCertGlobalRootCA.crt.pem", NULL, NULL);
self::$mysqli->real_connect(host', 'username', 'password', 'database'); // , 3306, MYSQLI_CLIENT_SSL);

//self::$mysqli = new mysqli('hots', 'username', 'password', 'database');   
return self::$mysqli;

Here is the full certificate for MySQL secure connection


Saturday, November 20, 2021

Some pitfalls for using PWA and ServiceWorkers I hoped I knew before

Some pitfalls for using PWA and ServiceWorker I hoped I knew before - So I am writing them here so maybe others will get to rid them before or I can find them again when I'll need them again.

This is not a tutorial for PWA, ServiceWorker. Those are just a few points that I encountered while developing a PWA (Progressive Web App) and ServiceWorker using Vanilla JavaScript and caching mechanism for Offline usage. There are plenty of good PWA ServiceWorker Caching tutorial on the internet.

Full Vanilla JavaScript code is attached all the way at the bottom

Double caches:

First, the cache made by the cache mechanism which you as a coder decide what will be saved in this cache using the cache.addAll() command.

And the second cache is the one the browser automatically caches for example images and javascripts code or others.

Hence might be that when you work offline the browser will return cached images which you did not stated that should be cached only because the browser caching mechanism have cached them.

Cache is empty offline from the website {ignoreVary: true}:

You develop and everything works cool from your localhost server but when deploying and installing on production on your website the offline cache of the serviceworker is empty in the devtools of your Chrome browser. When you work Online you do see the cache.

Now weather I think it appears empty it is a Chrome bug because the cache is there - apparently your code does not recognize the cache using caches.match and tries to request it from the network.

There are two things needed to be done:

  1. Use caches.match(e.request, {ignoreVary: true}) in your code telling the cache match comparing mechanism to ignore the request type and use only the URL itself
  2. When installing the serviceWorker it should be by default working under the same directory it is installed from. Unfortunately it doesn't always work. So when installing the serviceWorker use the scope parameter: navigator.serviceWorker.register('sw1.js', {scope: './'}) 

There can be only one instance of the ServiceWorker for the domain:

So no need to reinstall the worker when you go offline and the list of resources need to be relative to the service worker location:

const includeToCache = [
//  'loader.js?20211118a', // the serviceWorker loader
//  'sw1.js', // the serviceWorker itself

The full code of the serviceWorker

// service worker for PWA loaded from loader.js in pwa.class.php

const cacheName = 'pwa_v10';

const includeToCache = [
//  'loader.js?20211118a',
//  'sw1.js',

// Start the service worker and cache all of the app's content
self.addEventListener('install', e => {
    e.waitUntil( => {
            let c = cache.addAll(includeToCache).catch(err => console.log('SW install addAll FAIL:', err));
            return c;

// Serve cached content when offline
self.addEventListener('fetch', e => {
        caches.match(e.request, {ignoreVary: true}).then(response => {
            return response || fetch(e.request);

// replacing new cache if needed
self.addEventListener('activate', e => {
    // delete any caches that aren’t in cacheName
    // which will get rid of older versions
        caches.keys().then(keys => Promise.all(
   => {
                if(cacheName !== key) {
                    return caches.delete(key);
        }))).then(() => {
            console.log(cacheName + ' now ready to handle fetches!');

Wednesday, October 7, 2020

Using phpword to merge two Mircrosoft Office Word .docx documents

How to combine or embed and insert another .docx file (Microsoft office docx word document) into another one using PHPWord

Joining two .docx document using php (phpword library)

$mainTemplateProcessor = new \PhpOffice\PhpWord\TemplateProcessor("file1");
//$mainTemplateProcessor ->setValue('var_name', $value);

$innerTemplateProcessor = new \PhpOffice\PhpWord\TemplateProcessor("file2");
//$innerTemplateProcessor->setValue('var2_name', $value2);

// extract internal xml from template that will be merged inside main template
$innerXml = $innerTemplateProcessor->gettempDocumentMainPart();
$innerXml = preg_replace('/^[\s\S]*<w:body>(.*)<\/w:body>.*/', '$1', $innerXml);

// remove tag containing header, footer, images
$innerXml = preg_replace('/<w:sectPr>.*<\/w:sectPr>/', '', $innerXml);

// inject internal xml inside main template
$mainXml = $mainTemplateProcessor->gettempDocumentMainPart();
$mainXml = preg_replace('/<\/w:body>/', '<w:p><w:r><w:br w:type="page" /><w:lastRenderedPageBreak/></w:r></w:p>' . $innerXml . '</w:body>', $mainXml);


In order for the above code to work, you need to modify edit and add to the TemplateProcessor.php file those two functions:

public function gettempDocumentMainPart()
    return $this->tempDocumentMainPart;

public function settempDocumentMainPart($new)
    return $this->tempDocumentMainPart = $new;

This answer is based on the answer of @pfleu here:


Saturday, September 26, 2020

Teu Sonho - Online Interprete Seus Sonhos ( - Online Interprete Seus Sonhos é um software de interpretatação online de sonhos usando IA para análise em tempo real de sonhos repetidos e símbolos de sonhos.I took my website for dream analysis using Artificial Intelligence and Machine Learning that I have created in Hebrew and also in English and created a version in Portuguese with new dream symbols and new dreams.

Peguei meu site para análise de sonhos usando Inteligência Artificial e Aprendizado de Máquina que criei em hebraico e também em inglês e criei uma versão em português com novos símbolos de sonho e novos sonhos.

Also on twitter:


Online Interprete Seus Sonhos

Sunday, August 30, 2020

nginx rewrite and redirect rule like .htaccess in apache

In order to rewrite for example: to /symbol.php=casa

You can use:

location /symbol {
         rewrite ^/symbol/([^/\.]*)$ /symbol.php?symbol=$1;

Loading (importing) an .sql mysql dumpfile and showing progress bar

When loading and importing a large .sql mysql dump file and you wish to know how long is it going to take and where does the process status is standing using a progress bar from the mysqldump loading you can us pv (pipe viewer)

For example:

pv sqldumpfile.sql | mysql database name

About pv (pipe viewer) utility for Linux:

Tuesday, May 26, 2020

Connecting to MySQL 8 from Old PHP version using mysqli

If you have upgraded your MySQL to MySQL 8 version and still using older version of PHP you might encounter a few problems in the connection using mysqli connector library.

The first problem we are going to solve is:

php mysql 8: "Server sent charset (255) unknown to the client. Please, report to the developers"

The problem is that MySQL have changed the default character set from utf8 to utf8mb4 and it is not supported by mysqli connector (nor PDO as I have checked) in older versions of php.

"The default collation for utf8mb4 differs between MySQL 5.7 and 8.0 ( utf8mb4_general_ci for 5.7, utf8mb4_0900_ai_ci for 8.0). When the 8.0 client requests a character set of utf8mb4 , what it sends to the server is the default 8.0 utf8mb4 collation; that is, the utf8mb4_0900_ai_ci."

The way to solve it easily (there are other ways, such as upgrading php or connectors and more ...) is to force MySQL 8.0 to use UTF8 as default charset for connection.

Add those lines at the end of the my.cnf configuration file. In Ubunutu 20.04 it will be /etc/mysql/mysql.conf.d/mysqld.cnf

sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf

And add at the end (must be at the end of the file):


collation-server = utf8_unicode_ci
character-set-server = utf8
default_authentication_plugin = mysql_native_password

do not forget to restart the server after:
sudo service mysql restart

Second problem is new plugin for MySQL 8 passwords. Instead of the default mysql_native_password it is now using caching_sha2_password so you will get the error:  mysqli::__construct(): The server requested authentication method unknown to the client [caching_sha2_password]

The last line we added to the my.cnf file should fix it but not entirely. When creating the users inside your database make sure to CREATE USER or ALTER USER to use the mysql_native_password like that:

CREATE USER 'username'@`location` IDENTIFIED WITH mysql_native_password BY '[somepassword]'; 

That solved me some problems.

Monday, May 25, 2020

The way I use mysqldump

sudo mysqldump --master-data=1 --flush-logs --single-transaction --routines --quick --all-databases > db.sql

Friday, May 15, 2020

Simple system to track errors in code and find them easily


Here is a trick I developed during my years as a developer / programmer and team code leader. This system not just helps you to find the location of the error or warning in the code, but also who wrote it (without the need to open Git Blame or SVN log) and when was it coded in written.

They say that grep (find in all files) is the best friend of the programmer. Hence if you see an error in text or log file, let's say "Error: can't find configuration file". So you copy the text and "grep" it. It might be you would find this string in a few places scattered around the code.

So, we have started to give some Error Codes to the error. For example "Error: can't find configuration file (1029)". This will make it much easier and this unique error code is easy to search inside all the code files.

So how do you keep all the Error Codes unique ? Maybe a new programmer will add the same code number.

Do you keep a file with all Error Codes ?

Here is my system for assigning error codes:

"Error: some error description (ErrorCode: 20200515.1271726)"

And here is the format of the Error Code


YYYY, MM, DD - is obvious the date the code was written

HH, II - is the hour and minutes

The XXX is a unique number each of the coder team member identifier.

So let's say a programmer called Dani with code 019 have to add a new log  line with some warning or error. He will add 20200515.0191727 as the Error Code.
Next time I will see this code I can easily 'grep' it and I can also know who wrote this piece of code and when.

Believe me, it helps when the team is large.


Tuesday, March 24, 2020

Defragmentation and resizing to minimize HD size of a Virtual Machine Drive for Virtual Box

When creating a Virtual HD for Virtual Machine in Virtual Box, you can create a large disc space but the actual size on the disc can be much smaller until you fill it up.
But after you fill it, and then delete and try to free space the size on the host disc still remain large.

Here is how to resize the Virtual Drive HD on the host machine:

You have to do the following steps:

Run defrag in the guest (Windows only)
Nullify free space:

With a Linux Guest run this:
dd if=/dev/zero of=/var/tmp/bigemptyfile bs=4096k ; rm /var/tmp/bigemptyfile

telinit 1
mount -o remount,ro /dev/sda1
zerofree -v /dev/sda1
With a Windows Guest, download SDelete from Sysinternals and run this:

sdelete.exe c: -z
(replace C: with the drive letter of the VDI)

Shutdown the guest VM

Now run VBoxManage's modifymedium command with the --compact option:

With a Linux Host run this:

vboxmanage modifymedium --compact /path/to/thedisk.vdi
With a Windows Host run this:

VBoxManage.exe modifymedium --compact c:\path\to\thedisk.vdi
With a Mac Host run this:

VBoxManage modifymedium --compact /path/to/thedisk.vdi
This reduces the vdi size.

Wednesday, March 11, 2020

גרף שעוקב אחר התפשטות והדבקות נגיף הקורונה בארץ

העיתונות מפרסמת הרבה מספרים והרבה מלל. אז אני מנסה לתמצת את זה, ותמונה שווה יותר מאלף מילים וגרף שווה יותר. אז אני אוסף את פרומי העיתונות ועוקב כמה חולי קורונה חדשים יש לנו כל יום ושם את זה על גרף בשאיפה לראות מגמות, כמה נדבקים, כמה נדבקו בארץ מקורונה ולכמה תחלואה בארץ ישראל גורם הנגיף COVID-19. 

ניתן גם לראות את המספרים הגולמיים של חולי הקורנה, הדבקות חדשות, חולים קשה וכמה הבריאו מהנגיף ישירות במסמך Google Sheets שיצרתי על חולי הקורונה.

והנה גרף חולי הקורונה בארץ:

Saturday, March 7, 2020

Firefox notifications permissions fix for non secured domains (http and not https)

I had a running internal service inside an organization intranet. We wanted to allow notifications (web notifications) but we couldn't. In order to allow notifications for website and domains, both Firefox and Chrome requires https. Quite annoying since it is an Intranet inside the organization.

Trying to install a self-sign certificate or a signed certificate inside the organization (where there is no outside internet connectivity) it's really a pain in the a** and does not work well - and if you ask me it should be much easier and simple than it is.

I found a nice bypass workaround to allow notifications from websites and domains without SSL, hence http:// and not https:// for Firefox.

Firefox holds a file inside the Mozilla directory called permissions.sqlite which is a sqlite database file that holds the permissions for domains. You can add your domain there http://yourdomainname with permissions for notifications and it will work.

I have created a demonstration for Windows here in go (golang)

Tuesday, January 28, 2020

Fixing screen not waking up (xorg) on Ubuntu from command line

Sometimes after xubunutu screen is in hibernate mode the screen does not wake up.

Open terminal ALT+CTRL+F1 (tty)

  sleep 5 && xrandr -d :0 --output 'eDP-1' --primary --auto

Then switch fast back to the graphic mode (ALT+CTRL+F7) wait a few seconds for the screen to wake up.

'eDP-1' is the name of your screen

You can see connected screens running
    xrandr -d :0

Monday, September 16, 2019