On UNIX systems, IP ports with a number below 1024 are "privileged" ports, and only processes run by the superuser may listen on them. So if you want to configure the SAS web server to also service the "standard" ports 80 (http) and 443 (https), it must be started as root.
I have two web server instances running:
the SAS web server as-is out of the box, listening on port 7980, started from the SAS installation user
a simplified configuration, using the same binaries, started as root to handle the "main" ports, redirecting SAS-related requests to 7980
yes, it is applicable for all UNIX and Linux systems, included RHEL. The operating system will protect, as best practice, all ports from 0 to 1024 from being opened by non-root users.
You have some options:
* you can create an exception to this rule, at OS level, although not recommended * You can indeed modify the sas.servers and sas.servers.mid scripts to start web server as root (or sudo if sasinst is in the sudo whitelist) * You can use an external Web Server (IIS, Apache, the SAS Websetver as proposed above...) and configure SAS to use it. The external web server can listen in 89 or 443, then leave the SAS one listening on default port 7980.
To be honest, I recommend you to look up on the SAS documentation, the SAS Middle-tier Administration guide, for the Configuring SAS to use an external Reverse Proxy, which is the 3rd option in my bullet list, as best practice.