# AlmaLinux 9 Frequently asked questions

## How do I switch to a different version of PHP?

Execute the following command:

```shell
sudo dnf module switch-to php:remi-{major}.{minor} -y
```

where `{major}.{minor}` is one of the supported PHP versions: `8.5`, `8.4`, `8.3`, `8.2` and `8.1`.

Additionally, our setup includes predefined aliases for executing the above command.
The aliases are the following:

* `php81`: switch to PHP 8.1
* `php82`: switch to PHP 8.2
* `php83`: switch to PHP 8.3
* `php84`: switch to PHP 8.4
* `php85`: switch to PHP 8.5

After switching to a different PHP version, test with the following command:

```shell
php -v
```

Depending on the selected PHP version, the output should look similar to the below:

```terminaloutput
PHP 8.3.8 (cli) (built: Jun  4 2024 14:53:17) (NTS gcc x86_64)
Copyright (c) The PHP Group
Zend Engine v4.3.8, Copyright (c) Zend Technologies
```

## How do I switch to a different version of Node.js?

Execute the following commands:

```shell
sudo dnf remove nodejs -y
curl -fsSL https://rpm.nodesource.com/setup_{major}.x | sudo bash -
sudo dnf install nodejs -y
```

where `{major}` is the Node.js version you want to switch to.

Additionally, our setup includes predefined aliases for the above commands.
The aliases are the following:

* `node24`: switch to Node.js 24
* `node22`: switch to Node.js 22
* `node20`: switch to Node.js 20
* `node18`: switch to Node.js 18

After switching to a different Node.js version, test with the following command:

```shell
node -v
```

Depending on the selected Node.js version, the output should look similar to the below:

```terminaloutput
v24.13.0
```

Check npm version:

```shell
npm -v
```

Depending on the current npm version, the output should look similar to the below:

```terminaloutput
11.9.0
```

## How do I fix common permission issues?

If running your project, you encounter permission issues, follow the below steps.

### Error

> PHP Fatal error: Uncaught InvalidArgumentException: The directory "`<path-to-project>`/data" is not writable...

> PHP Fatal error: Uncaught InvalidArgumentException: The directory "`<path-to-project>`/data/cache" is not writable...

> PHP Fatal error: Uncaught InvalidArgumentException: The directory "`<path-to-project>`/data/cache/doctrine" is not writable...

### Solution

```shell
chmod -R 777 data
```

### Error

> PHP Fatal error: Uncaught InvalidArgumentException: The directory "`<path-to-project>`/public/uploads" is not writable...

### Solution

```shell
chmod -R 777 public/uploads
```

### Error

> PHP Fatal error: Uncaught ErrorException: fopen(`<path-to-project>`/log/error-log-yyyy-mm-dd.log): Failed to open stream: Permission denied...

### Solution

```shell
chmod -R 777 log
```

## Where are the error log files?

From time to time, you are encountering various errors which are not displayed. Or you can get errors 500 in a browser.

To find the error messages, you need to read the error log files.

### Apache log files

```text
/var/log/httpd/error_log
```

### PHP-FPM log files

```text
/var/log/php-fpm/error.log
/var/log/php-fpm/www-error.log
```

## How do I update Composer?

Before updating, check your current Composer version by executing:

```shell
composer --version
```

The output should be similar to:

```text
Composer version 2.9.0 2025-11-13 10:37:16
PHP version 8.5.0 (/usr/bin/php)
Run the "diagnose" command to get more detailed diagnostics output.
```

Update Composer using its own `self-update` command:

```shell
sudo /usr/local/bin/composer self-update
```

The output should be similar to:

```text
Upgrading to version 2.8.8 (stable channel).

Use composer self-update --rollback to return to version 2.8.5
```

After updating, check again your Composer version by executing:

```shell
composer --version
```

The output should be similar to:

```text
Composer version 2.8.8 2025-04-04 16:56:46
PHP version 8.3.20 (/usr/bin/php)
Run the "diagnose" command to get more detailed diagnostics output.
```

## How do I update phpMyAdmin?

Being installed as a system package, it can be updated using the command which updates the rest of the system packages:

```shell
sudo dnf upgrade -y
```

## How do I delete a virtualhost?

If for whatever reason you want to delete a virtualhost, for instance `to-be-deleted.localhost` you need to do the following:

* Delete the folder where the files are located

```shell
sudo rm -rf /var/www/to-be-deleted.localhost
```

* Delete the Apache configuration file

```shell
sudo rm -f /etc/httpd/sites-available/to-be-deleted.localhost.conf
```

* Restart httpd server

```shell
sudo systemctl restart httpd
```

## How do I create command aliases?

From either your terminal or file explorer, navigate to your home directory (`/home/<your-username>/`).

Using your preferred text editor, open the file: `.bash_profile` (if it does not exist, creat it first).

Move to the end of the file and enter on a new line:

```text
alias command_alias="command to execute"
```

where:

* `command_alias` is the name by which you want to call your original command
* `command to execute`: the original command to be executed on alias call

### Example

```text
alias list_files="ls -Al"
```

will create an alias called `list_files` that will run the command `ls -Al`.

Then, you can execute your custom alias in a terminal just as a regular command:

```shell
list_files
```