.TH s/qmail: 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
.B tcpclient 
and
.B tcpserver 
as well as
.BR sslclient 
and 
.BR sslserver .

Note that
.BR TCPLOCALHOST ,
.BR TCP6LOCALHOST ,
.BR TCPREMOTEHOST ,
.BR TCP6REMOTEHOST ,
and
.BR TCPREMOTEINFO ,
.BR TCP6REMOTEINFO ,
can contain arbitrary characters.
.TP 5
PROTO
The string
.BR TCP ,
or
.BR TCP6 .
.TP 5
TCPLOCALHOST/TCP6LOCALHOST 
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,
.BR TCPLOCALHOST ,
.B TCP6LOCALHOST
is not set.
.TP 5
TCPLOCALIP
The IPv4 address of the local host, in dotted-decimal form.
.TP 5
TCP6LOCALIP
The compactified IPv6 address of the local host.
.TP 5
TCPLOCALPORT/TCP6LOCALPORT
The local TCP port number, in decimal.
.TP 5
TCPREMOTEHOST/TCP6RMOTEHOST
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
or 
.B TCP6REMOTEHOST 
is not set.
.TP 5
TCPREMOTEINFO/TCP6REMOTEINFO
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,
.BR TCPREMOTEINFO ,
.B TCP6REMOTEINFO
is not set.
.TP 5
TCPREMOTEIP
The IPv4 address of the remote host.
.TP 5
TCP6REMOTEIP
The IPv6 address of the remote host.
.TP 5
TCPREMOTEPORT/TCP6REMOTEPORT
The remote TCP port number.
.TP 5
TCP6INTERFACE
contains the interface name for IPv6 connections.

.SH "SEE ALSO"
tcpclient(1),
tcpserver(1),
sslclient(1),
sslserver(1),
tcp(4)