.TH tcp-environ 5 .SH NAME tcp-environ \- TCP-related environment variables .SH DESCRIPTION The following environment variables describe a TCP connection. They are set up by .BR tcp-env , .BR tcpclient , and .BR tcpserver . Note that .BR TCPLOCALHOST , .BR TCPREMOTEHOST , and .B TCPREMOTEINFO can contain arbitrary characters. .TP 5 PROTO The string .BR TCP . .TP 5 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, .B TCPLOCALHOST is not set. .TP 5 TCPLOCALIP The IP address of the local host, in dotted-decimal form. .TP 5 TCPLOCALPORT The local TCP port number, in decimal. .TP 5 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, .B TCPREMOTEHOST is not set. .TP 5 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, .B TCPREMOTEINFO is not set. .TP 5 TCPREMOTEIP The IP address of the remote host. .TP 5 TCPREMOTEPORT The remote TCP port number. .SH "SEE ALSO" tcpclient(1), tcpserver(1), tcp-env(1), tcp(4)