# Customer SSH - Useful Commands
Enter a customer's application container To enter a website container as a customer, you can either:
Add your SSH key through "developer tools" in the UI when viewing the customer's website. SSH to username@server_ip as directed in the UI. Log in as root and type
su - customer_username
Either way you will be within the customer's containerised PHP environment and you will have access to exactly the same file structure and binaries that the customer's PHP applications will use. You can also see their PHP processes and any sub processes which might be forked.
Running PHP CLI:
The PHP binary is /usr/bin/php - this will be whatever version of PHP the customer has selected in their dashboard (under "developer tools").
php script.php
You will immediately see the output of the script. Many website scripts will behave in a similar way via CLI as they do on the web and this may help with debugging.
You can also run
strace php script.php
This will let you see the system calls which PHP is making - for instance if it's trying to read a particular file or connect to an IP address. This is also very useful for debugging.
Piping output
You may want to send the output of the script to a file. For example:
php script.php > script.log
Will send the output (stdout) to script.log
php script.php > script.log 2>&1
Will send both stdout and stderr to script.log.
/usr/bin/composer
This is PHP composer, a dependency manager for PHP. It may be required for installations of some scripts. Note that this requires appcd 1.1.0 and above.
/usr/bin/wp-cli
This is WP CLI, a suite of CLI commands for use with WordPress. You can install/update plugins, manage users and much more.
/usr/bin/top
This will show you the processes running inside the website's PHP container including how much CPU and memory they are using. A php-fpm or lsphp process using a high CPU percentage for a long time might have an infinite loop or contain malware.
/usr/bin/rm
Removes a file
/usr/bin/mkdir
Makes a new directory
/usr/bin/chmod
Changes file or directory permissions
*Copying files
You and your customers also have access to ssh and rsync binaries which are very useful for transferring websites from other servers without the risk of using root privileges.
Crontab
Please note, it is not possible to edit crontab from the customer's SSH environment at this time. Instead you need to use the control panel UI under "developer tools".