Category: Programming – Page 2

PHP running system commands with exec

Posted on December 31, 2018 by ServerOk

To execure a system command on a server, use PHP exec function. For example

<?php

@exec("nslookup yahoo.com 2>&1", $result);
echo "<pre>";
print_r($result);

<?php

@exec("nslookup yahoo.com 2>&1", $result);

echo "<pre>";

print_r($result);

See php […]

Ruby

Posted on December 27, 2018 (October 11, 2020) by ServerOk

Install ruby from source Install rvm (ruby version manager) Nginx Rails Origin header didn’t match request.base_url Gem Package Manager Gem – Package Manager for Ruby Upgrade ruby gem […]

Python

Posted on August 31, 2018 (July 18, 2020) by ServerOk

Install Python 3.8 on CentOS 6 from source Install python 3.6 on CentOS 7 Install Python 2.7 on CentOS 6 pip Install jupyter notebook virtualenv Running Web Server with python SimpleHTTPServer Hosting Python Application in Production gunicorn Python Errors error: Python.h: No such file or directory pip install mysqlclient mysql_config: not found ERROR: Failed building […]

Magento 1.9 store login not working in Chrome

Posted on April 18, 2018 (April 18, 2018) by ServerOk

On a site running Magento 1.9, user login is not working on Google Chrome. The problem is due to cookie setting in Magento. Login to Magento Admin, go to Admin > System > configuration > web > Session and Cookie Management Put your domain name in “Cookie Domain” text box and click Save Config. Magento […]

Laravel

Posted on March 10, 2018 (November 12, 2020) by ServerOk

Laravel Database Migration Error Key too long How to find Laravel Framework Version Create project using latest laravel

composer create-project --prefer-dist laravel/laravel blog

1	composer create-project --prefer-dist laravel/laravel blog

Create project using specific version of laravel.

composer create-project laravel/laravel=5.1.33 --prefer-dist blog

1	composer create-project laravel/laravel=5.1.33 --prefer-dist blog

You can see available laravel versions on site https://packagist.org/packages/laravel/laravel […]

Laravel Database Migration Error Key too long

Posted on March 10, 2018 (September 30, 2018) by ServerOk

When doing a database migration on Laravel, i get following error

$ php artisan migrate

  [Illuminate\Database\QueryException]                                                                                                                                                 
  SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes (SQL: alter table `users` add unique `users_email_unique`(`email`))  

  [PDOException]                                                                                                   
  SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes  
$

$ php artisan migrate

[Illuminate\Database\QueryException]

SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes (SQL: alter table `users` add unique `users_email_unique`(`email`))

[PDOException]

SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

This is because MariaDB use different UTF8 format. To fix, edit file

vi ./app/Providers/AppServiceProvider.php

1	vi ./app/Providers/AppServiceProvider.php

Inside, find

    public function boot()
    {
        //
    }

public function boot()

{

}

Replace with

    public function boot()
    {
        Schema::defaultStringLength(191);
    }

public function boot()

{

Schema::defaultStringLength(191);

}

You will also need to add

use Illuminate\Support\Facades\Schema;

1	use Illuminate\Support\Facades\Schema;

here is how my file look like after editing.

$ cat ./app/Providers/AppServiceProvider.php
<?php

namespace App\Providers;

use Illuminate\Support\Facades\Schema;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        Schema::defaultStringLength(191);
    }

    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        //
    }
}
$

$ cat ./app/Providers/AppServiceProvider.php

<?php

namespace App\Providers;

use Illuminate\Support\Facades\Schema;

use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider

{

/**

* Bootstrap any application services.

* @return void

public function boot()

{

Schema::defaultStringLength(191);

}

/**

* Register any application services.

* @return void

public function register()

{

}

Laravel […]

nodemon

Posted on February 22, 2018 (February 22, 2018) by ServerOk

Node.js applications when you run with nodejs command, you need to restart when a change is made to source code of the application. nodemon will watch your application source code for changes, restart if a change is detected. To install nodemon, run

npm install -g nodemon

1	npm install -g nodemon

Example

nodemon app.js 3000

1	nodemon app.js 3000

nodejs […]

pm2 process manager for node.js

Posted on February 21, 2018 (July 28, 2019) by ServerOk

Auto Start pm2 on boot pm2 is a process manager for node.js applications. It is similar to forever. http://pm2.keymetrics.io First you need to install npm, on Ubuntu/Debian, run

apt install npm

1	apt install npm

To install pm2, run

npm install pm2 -g

1	npm install pm2 -g

Start an Application

pm2 start app.js

1	pm2 start app.js

Start an Application with name

pm2 start app.js -n "app-name-here"

1	pm2 start app.js -n "app-name-here"

Start Application in Cluster mode with

pm2 start app.js -n "app-name-here" -i 5

1	pm2 start app.js -n "app-name-here" -i 5

To Scale a clustered […]

Check if PHP session is working

Posted on February 10, 2018 by ServerOk

To check if PHP session is working, upload following script

<?php 

session_start();

if (isset($_SESSION["ServerOk"])) {
    $_SESSION["ServerOk"] += 1;
} else {
    $_SESSION["ServerOk"] = 1;
}

echo $_SESSION["ServerOk"];

<?php

session_start();

if (isset($_SESSION["ServerOk"])) {

$_SESSION["ServerOk"] += 1;

} else {

$_SESSION["ServerOk"] = 1;

}

echo $_SESSION["ServerOk"];

Access the file, refresh the page in browser, if you see number increase with every refresh, PHP session is working properly on server. […]

Ruby On Rails

Posted on February 4, 2018 (January 30, 2019) by ServerOk

To create a ruby on rails project, run

rails new

rails new

Nginx Rails Origin header didn’t match request.base_url […]