### Supported Systems

APT is supported on Redhat Enterprise Linux. APT is currently tested on RHEL 7.6 system. The basic OS requirement is RHEL 6.9 (or better), Ubuntu 16.04 (or better) (and equivalents).

APT is available for 64-bit kernal computers only. (To determine which you have type: "uname -a". If you see "x86_64" you have a 64-bit kernel.)

Depending on your institution's computer security measures (firewalls, blocked ports, etc.), you may initially have communication trouble with APT. If you have any concerns please see our Server Connectivity knowledge article.

#### 1. Uninstall the previous version

Note: If you are going to install APT in the same directory as a previous version, please remove the previous version first. But if you are going to install in a separate directory, you would only need to uninstall to save disk space (and possible version confusion).

To get rid of the old version: Delete the entire directory tree where you installed it. (The unix command

rm -rf [directory]

makes this quick because it gets rid of all the subdirectories and does not ask you about overriding permissions.)

To install type:  sh install-linux-apt.sh

View the SHA Number

#### 3. Start

Once you have installed APT you invoke it with a script. For instance to start APT type

./APT

in the installation directory. (By default the installation directory is placed in your home directory.) Links are no longer put in your home directory automatically. If you would like to create your own link, here is is the unix command to use in your home directory to create a link named 'apt':

ln -s [your_installation_directory]/APT apt

#### 4. How to find out about new releases

We maintain a distribution list for announcing new releases of APT. This may be helpful to people who install APT for others to use. Just send a blank email to: apt_release_notice-subscribe-request@maillist.stsci.edu (Unsubscribe by sending a blank email to apt_release_notice-signoff-request@maillist.stsci.edu)

#### 5. Troubleshooting

If there are problems with the installation you can turn on debug logging and sometimes that will reveal the problem. This debug log would also be useful to send us if you can't figure out the problem. Contact us (through help@stsci.edu) if you have problems with installation. It would also be useful to tell us your exact flavor of linux which you can get from the commands:

uname -a

and

more /etc/issue

To turn debug logging on during installation: Execute these commands in the directory where you downloaded the installer (install-linux-apt.sh):

sh install-linux-apt.sh --keep --noexec

cd install-linux-apt

jre/bin/java -DTRACE=true -jar install-linux-apt.jar

To turn debug logging on while running APT: add a command line switch when you invoke APT:

./APT -debug all