Tcp-related environment variables
The following environment variables describe a TCP connection. They are set up by tcp-env, tcpclient, and tcpserver. Note that TCPLOCALHOST, TCPREMOTEHOST, and TCPREMOTEINFO can contain arbitrary characters.
PROTO
The string TCP.
TCPLOCALHOST
The domain name of the local host, with uppercase letters converted to lowercase. If there is no currently available domain name for the local IP address, TCPLOCALHOST is not set.
TCPLOCALIP
The IP address of the local host, in dotted-decimal form.
TCPLOCALPORT
The local TCP port number, in decimal.
TCPREMOTEHOST
The domain name of the remote host, with uppercase letters converted to lowercase. If there is no currently available domain name for the remote IP address, TCPREMOTEHOST is not set.
TCPREMOTEINFO
A connection-specific string, perhaps a username, supplied by the remote host via 931/1413/IDENT/TAP. If the remote host did not supply connection information, TCPREMOTEINFO is not set.
TCPREMOTEIP
The IP address of the remote host.
TCPREMOTEPORT
The remote TCP port number.
tcpclient(1), tcpserver(1), tcp-env(1), tcp(4)