tcpclient − create an outgoing TCP connection
tcpclient [ −46hHrRdDqQv ] [ −ilocalip ] [ −plocalport ] [ −Ttimeoutconn ] [ −llocalname ] [ −ttimeoutinfo ] [ −Iifname ] host port program [ arg ... ]
tcpclient attempts to connect to a TCP server. If it is successful, it runs program with the given arguments, with descriptor 6 reading from the network and descriptor 7 writing to the network.
The server’s address is given by host and port. host may be 0, referring to the local machine, a compactified IPv6 address. or a dotted-decimal IPv4 address, or a host name; if a host has several IP addresses, tcpclient tries each in turn. port may be a numeric port number or a port name.
tcpclient sets up several environment variables, as described in tcp-environ(5).
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−4 |
Fall back to IPv4 sockets. | ||
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−6 |
Force IPv6 mode in UCSPI environment variables, even for IPv4 connections. This will set PROTO to TCP6 and put IPv4-mapped IPv6 addresses in TCPLOCALIP and TCPREMOTEIP. |
−ilocalip
Use localip as the IP address for the local side of the connection; quit if localip is not available.
−plocalport
Use localport as the port number for the local side of the connection; quit if localport is not available.
−Iifname
Use ifname as the local network interface. This is only defined for IPv6 sockets and needed if you use link-local IPv6 addresses.
−Ttimeoutconn
Give up on the connection attempt after timeoutconn seconds. Default: 60. This timeout applies to each IP address tried.
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−d |
(Default.) Delay sending data for a fraction of a second whenever the remote host is responding slowly, to make better use of the network. | ||
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−D |
Never delay sending data; enable TCP_NODELAY. This is appropriate for interactive connections. | ||
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−q |
Quiet. Do not print any messages. | ||
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−Q |
(Default.) Print error messages. | ||
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−v |
Verbose. Print all available messages. |
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−h |
(Default.) Look up the remote host name for TCPREMOTEHOST. |
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−H |
Do not look up the remote host name; unset TCPREMOTEHOST. |
−llocalname
Do not look up the local host name; use localname for TCPLOCALHOST.
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−r |
(Default.) Attempt to obtain TCPREMOTEINFO from the remote host. | ||
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−R |
Do not attempt to obtain TCPREMOTEINFO from the remote host. |
−ttimeoutinfo
Give up on the TCPREMOTEINFO connection attempt after timeoutinfo seconds. Default: 26.
tcpclient reads the environment variable DNSCACHEIP which can be used to specify the recursive DNS Resolver dynamically.
date@(1), finger@(1), http@(1), mconnect(1), tcpcat(1), tcpserver(1), who@(1), tcp-environ(5)