What is SSH_AUTH_SOCK?

When I export in my terminal I see:

declare -x Apple_PubSub_Socket_Render="/private/tmp/com.apple.launchd.zTF2WfVZJa/Render"
declare -x DISPLAY="/private/tmp/com.apple.launchd.qhUQdpRp4B/org.macosforge.xquartz:0"
declare -x SSH_AUTH_SOCK="/private/tmp/com.apple.launchd.PowIf5erzI/Listeners"

What are these entries?

1 Answer

In general terms, these lines are user-scoped variables used by applications that you may run. The top two settings appear to be used by the X-Server system. The values may be hard coded, or they may point to a file that contains the information required.

SSH_Auth_Sock is used by OpenSSH for passwordless (key based) authentication. It is my supposition that the files pointed to in those profile settings contain temporary data about the services that use them. For instance the listeners file would contain the port numbers that the ssh service is listening for incoming requests connections, which may change based on administrative choices or runtime conditions.

The Display line indicates the current X-Server virtual display port in use. Notice that the line contains the string xquartz. It is my understanding that the Mac windowing system is called Quartz.

I'm not a mac guy, so can't tell you for sure, but the Render line looks to be related to the X servers Direct Rendering Interface

Edit:

Upon additional research, I realize I was wrong about the Apple_PubSub_Socket_Render setting. it is related to the Mac RSS/Atom client PubSub.