TCPING(1)                        User Manuals                        TCPING(1)



NAME
       tcping - non-blocking TCP connection test

SYNOPSIS
       tcping [-q] [-f <4|6> ] [-t timeout-sec | -u timeout-usec ] host port

DESCRIPTION
       tcping attempts to complete a TCP connection to a host:port combination
       within the time interval timeout-[u]sec.  The result of  the  operation
       is encoded as a return value.

OPTIONS
       -q     Quiet flag. Suppress all informational output.

       -f <4|6>
              IP  protocol  family  to  use:  4 for IPv4, 6 for IPv6.  If left
              unspecifed, the implementation will use the protocol  family  of
              the first record returned from getaddrinfo(3), based on the for-
              mat of the host parameter.  Specifying  host  as  dotted-decimal
              IPv4 or hex IPv6 address string will use the respective protocol
              stack. Specification as a hostname character string will cause a
              dependency  on  the order of IPv4 and IPv6 records returned from
              getaddrinfo(3).

       -t timeout-sec
              Connection timeout in seconds.

       -u timeout-usec
              Connection timeout in microseconds.

       host   Destination host. Either a host name node name or a numeric host
              address  string  (i.e., a dotted-decimal IPv4 address or an IPv6
              hex address), per RFC 2553.

       port   Destination port. Either a service name or a decimal  port  num-
              ber, per RFC 2553.

RETURN VALUES
       tcping  encodes  the  result  of  the  connection attempt in its return
       value:

       0      The connection attempt was successful.

       1      The connection attempt was unsuccessful.

       2      The connection attempt timed out.

       255    An error occured.

DIAGNOSTICS
       Unless the quiet (-q) flag is set, the following diagnostics are issued
       on  stderr.  The  messages  align  with  the  program return value (see
       above).

       <host> port <port> open.
              The connection attempt to host:port was successful.
       <host> port <port> closed.
              The connection attempt to host:port  was  unsuccessful  and  the
              server side signaled a closed port.
       <host> port <port> user timeout.
              The  connection attempt to host:port did not complete within the
              user-defined timeout interval.

AUTHOR
       Marc Kirchner <mail at marc-kirchner dot de>

HISTORY
       tcping came to be in 2002 as a utility to allow  basic  TCP  connection
       checking  and  to  enable  failure shortcircutry before issuing network
       commands with long timeouts (on  Solarix  2.x,  Solaris  7/8,  AIX  and
       Linux).  IPv6  functionality  was  added  for 2.0.0 in 2023, which also
       dropped support for the AIX and Solaris OS.

ACKNOWLEDGEMENTS
       Many thanks to Kai Hambrecht, John Smith and Vincent Loriot.

SEE ALSO
       nc(1)




Linux                             MARCH 2023                         TCPING(1)