[BusyBox] Detecting nature of terminal access

[Vic Berdin]

Hi,

I would like to ask if I can use the busybox project in order to detect 
the nature of terminal access to my Linux box. To be more specific, I
would like to know if busybox (via login or sh or others?), is raising 
a terminal/shell for a telnet connection, serial console, or for a direct
"stdin" connection.
Actually, I'm thinking of doing this by creating my own, very minimal 
shell environment, and process the nature of access from there. However,
my idea of detecting the nature of terminal access is very minimal.
Aside from using netstat for telnet, whatelse can I use to determine stdin
from serial console access?
Any advise is highly appreciated.

TIA - Vic

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