From e0fc82203d677a6f1e808e9a1a46176c109d89be Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Mon, 15 Dec 2014 23:08:59 +0000 Subject: Initial commit --- doc/s6-tcpclient.html | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 doc/s6-tcpclient.html (limited to 'doc/s6-tcpclient.html') diff --git a/doc/s6-tcpclient.html b/doc/s6-tcpclient.html new file mode 100644 index 0000000..42edaa9 --- /dev/null +++ b/doc/s6-tcpclient.html @@ -0,0 +1,133 @@ + + + + + s6-networking: the s6-tcpclient program + + + + + + +

+ +

The `s6-tcpclient` program

+ +

+s6-tcpclient is an +UCSPI client tool for +INET domain sockets. It establishes a TCP connection to a server, +then executes into a program. +

+ +

Interface

+ +

+     s6-tcpclient [ -q | -Q | -v ] [ -4 | -6 ] [ -d | -D ] [ -r | -R ] [ -h | -H ] [ -n | -N ] [ -t timeout ] [ -l localname ] [ -T timeoutconn ] [ -i localip ] [ -p localport ] host port prog...
+

+ +

s6-tcpclient establishes a TCP connection to host host +port port.
It executes into prog... with descriptor 6 reading from +the network and descriptor 7 writing to it.

+ +

Host address determination

+ +

host may be an IP address, in which case s6-tcpclient will +connect to that IP address. If the underlying skalibs has been +compiled with IPv6 support, host can be an IPv6 address as +well as an IPv4 one.
host may be a domain name, in which case a DNS +resolution will be performed on it, and a connection will be tried to +all the resulting IP addresses in a round-robin fashion, twice: +first with a small timeout, then with a longer timeout. The first +address to answer wins. The connection attempt fails if no address +in the list is able to answer.

+ +

Environment variables

+ +

+ prog... is run with the following variables set: +

+ +

PROTO: always set to TCP
TCPREMOTEIP: set to the chosen IP address of host.
TCPREMOTEPORT: set to port.
TCPREMOTEHOST: if the -H has been given, set to the +name obtained by a reverse DNS resolution of the IP address chosen +for host. Else unset.
TCPLOCALHOST: if the -l option has been given, set to +localname. Else set to the name obtained by a reverse DNS +resolution of the IP address chosen for the local host.
TCPREMOTEINFO: if the -r option has been given, set +to the information given by an IDENT server on host about +the current connection (very unreliable). Else unset.

+ +

Options

+ +

-q : be quiet.
-Q : be normally verbose. This is the default.
-v : be verbose.
-4 : (only valid if the underlying skalibs has +IPv6 support) Interpret host as an IPv4 address or make A +queries to determine its addresses.
-6 : (only valid if the underlying skalibs has +IPv6 support) Interpret host as an IPv6 address or make +AAAA queries to determine its addresses. This option and the previous +one are not mutually exclusive: if both are given, both IPv6 and +IPv4 addresses will be tried and IPv6 addresses will be given priority. +If neither option is given, only IPv4 address will be tried.
-d : don't use the TCP_NODELAY socket option. This +is the default.
-D : use the TCP_NODELAY socket option, which disables +Nagle's algorithm.
-r : try and obtain a TCPREMOTEINFO string via the +IDENT protocol. This is obsolete and unreliable, and should only be used for +compatibility with legacy programs.
-R : do not use the IDENT protocol. This is the +default.
-h : try and obtain the remote host name via DNS. +This is the default.
-H : do not try and obtain the remote host name +via DNS.
-n : qualify host when resolving it to +find suitable IP addresses. This is the default.
-N : do not qualify host.
-t :timeout : put a global timeout +on the connection attempt. If no fully functional connection has been +established after timeout seconds, abort the program. By +default, timeout is 0, which means no timeout.
-i localip : use localip as +the local socket address for the connection. By default, address selection +is left to the operating system.
-p localport : use localport +as the local socket port for the connection. By default, port selection +is left to the operating system.
-l localname : use localname +as the value of the TCPLOCALPATH environment variable instead of +looking it up via the DNS.
-T :timeoutconn : configure the +connection timeouts. timeoutconn must be of the form +x+y, where x and y are +integers. x is the first timeout and y is the +second one: all suitable addresses for host are first +tried with a timeout of x seconds, and if all of them +fail, then they are tried again with a timeout of y +seconds. (Be aware that the timeout specified with the -t +option overrides everything.) By default, x is 2 and +y is 58.

+ + + -- cgit v1.2.3

The s6-tcpclient program

Interface

Host address determination

Environment variables

Options

The `s6-tcpclient` program