tcpclient
Section: User Commands (1)
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NAME
tcpclient - creates an outgoing TCP connection.
SYNOPSIS
tcpclient
[
opts
]
host
port
prog
DESCRIPTION
opts
is a series of getopt-style options.
host
is one argument.
port
is one argument.
prog
consists of one or more arguments.
tcpclient
attempts to connect to a TCP server. If it is successful, it runs
prog,
with descriptor 6 reading from the network and descriptor 7 writing to the
network. It also sets up several environment variables (see
tcp-environ(5)
).
The server's address is given by
host
and
port.
port
may be a name from /etc/services or a number.
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,
tcpclient
tries each address in turn.
OPTIONS
General options:
- -q
-
Quiet. Do not print error messages.
- -Q
-
(Default.) Print error messages.
- -v
-
Verbose. Print error messages and status messages.
Connection options:
- -T x+y
-
Give up on the connection attempt after
x+y
seconds. Default: 2+58. When a host has several IP addresses,
tcpclient
tries to connect to the first IP address, waits
x
seconds, tries to connect to the second IP address, waits
x
seconds, etc.; then it retries each address that timed out, waiting
y
seconds per address. You may omit
+y
to skip the second try. Before version 0.88,
tcpclient(1)
will use only
x
(default: 60).
- -i localip
-
Use
localip
as the IP address for the local side of the connection; quit if
localip
is not available. Normally
tcpclient
lets the operating system choose an address.
- -p localport
-
Use
localport
as the TCP port for the local side of the connection; quit if
localport
is not available. Normally
tcpclient
lets the operating system choose a port.
- -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.
- -D
-
Never delay sending data; enable TCP_NODELAY.
Data-gathering options:
- -h
-
(Default.) Look up the remote host name in DNS to set the environment variable
$TCPREMOTEHOST.
- -H
-
Do not look up the remote host name in DNS; remove the environment variable
$TCPREMOTEHOST.
- -l localname
-
Do not look up the local host name in DNS; use
localname
for the environment variable $TCPLOCALHOST. A common choice for localname is
0.
- -r
-
(Default.) Attempt to obtain $TCPREMOTEINFO from the remote host.
- -R
-
Do not attempt to obtain $TCPREMOTEINFO from the remote host.
- -t n
-
Give up on the $TCPREMOTEINFO connection attempt after
n
seconds. Default: 26.
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