.TH tcpclient 1
.SH NAME
tcpclient \- creates an outgoing TCP connection.
.SH SYNOPSIS
.B tcpclient
[
.I opts
]
.I host
.I port
.I prog
.SH DESCRIPTION
.I opts
is a series of getopt-style options.
.I host
is one argument.
.I port
is one argument.
.I prog
consists of one or more arguments. 

.B tcpclient
attempts to connect to a TCP server. If it is successful, it runs
.IR prog ,
with descriptor 6 reading from the network and descriptor 7 writing to the
network. It also sets up several environment variables (see
.BR tcp-environ (5)
).

The server's address is given by
.I host
and
.IR port .
.I port
may be a name from /etc/services or a number.
.I host
may be 0, referring to the local machine, or a dotted-decimal IP address, or
a host name; it is fed through qualification using dns_ip4_qualify.

If the server has several IP addresses,
.B tcpclient
tries each address in turn.
.SH OPTIONS
.B General options:
.TP
.B \-q
Quiet. Do not print error messages. 
.TP
.B \-Q
(Default.) Print error messages. 
.TP
.B \-v
Verbose. Print error messages and status messages. 
.P
.B Connection options:
.TP
.B \-T \fIx\fR+\fIy
Give up on the connection attempt after
.I x\fR+\fIy
seconds. Default: 2+58. When a host has several IP addresses,
.B tcpclient
tries to connect to the first IP address, waits
.I x
seconds, tries to connect to the second IP address, waits
.I x
seconds, etc.; then it retries each address that timed out, waiting
.I y
seconds per address. You may omit
.RI + y
to skip the second try. Before version 0.88,
.BR tcpclient (1)
will use only
.I x
(default: 60). 
.TP
.B \-i \fIlocalip
Use
.I localip
as the IP address for the local side of the connection; quit if
.I localip
is not available. Normally
.B tcpclient
lets the operating system choose an address. 
.TP
.B \-p \fIlocalport
Use
.I localport
as the TCP port for the local side of the connection; quit if
.I localport
is not available. Normally
.B tcpclient
lets the operating system choose a port. 
.TP
.B \-d
Delay sending data for a fraction of a second whenever the remote host is
responding slowly. This is currently the default, but it may not be in the
future; if you want it, set it explicitly. 
.TP
.B \-D
Never delay sending data; enable TCP_NODELAY. 
.P
.B Data-gathering options:
.TP
.B \-h
(Default.) Look up the remote host name in DNS to set the environment variable
$TCPREMOTEHOST. 
.TP
.B \-H
Do not look up the remote host name in DNS; remove the environment variable
$TCPREMOTEHOST. 
.TP
.B \-l \fIlocalname
Do not look up the local host name in DNS; use
.I localname
for the environment variable $TCPLOCALHOST. A common choice for localname is
0.
.TP
.B \-r
(Default.) Attempt to obtain $TCPREMOTEINFO from the remote host.
.TP
.B \-R
Do not attempt to obtain $TCPREMOTEINFO from the remote host. 
.TP
.B \-t \fIn
Give up on the $TCPREMOTEINFO connection attempt after
.I n
seconds. Default: 26. 
.SH SEE ALSO
tcpserver(1),
tcprules(1),
tcprulescheck(1),
argv0(1),
fixcrio(1),
recordio(1),
rblsmtpd(1),
who@(1),
date@(1),
finger@(1),
http@(1),
tcpcat(1),
mconnect(1),
tcp-environ(5)

http://cr.yp.to/ucspi-tcp.html