telnet-probe(1) — Linux manual page


TELNET-PROBE(1)            General Commands Manual           TELNET-PROBE(1)

NAME         top

       telnet-probe - lightweight telnet-like port probe

SYNOPSIS         top

       $PCP_BINADM_DIR/telnet-probe [-cv?]  host port

DESCRIPTION         top

       telnet-probe allows the pmdashping(1) daemons to establish
       connections to arbitrary local and remote service-providing daemons
       so that response time and service availability information can be

       The required host and port number arguments have the same meaning as
       their telnet(1) equivalents.

       The -c option causes telnet-probe to perform a connect(2) only.  This
       skips the read(2) and write(2) exercise that would otherwise be done
       after connecting (see below).

       Once the telnet connection has been established, telnet-probe reads
       from stdin until end-of-file, and writes all the input data to the
       telnet connection.  Next, telnet-probe will read from the telnet
       connection until end-of-file, discarding whatever data it receives.
       Then telnet-probe exits.

       To operate successfully, the input passed via telnet-probe to the
       remote service must be sufficient to cause the remote service to
       close the connection when the last line of input has been processed,
       e.g. ending with ``quit'' when probing SMTP on port 25.

       By default telnet-probe will not produce any output, unless there is
       an error in which case a diagnostic message can be displayed (in
       verbose mode only) and the exit status will be non-zero indicating a

OPTIONS         top

       The available command line options are:

       -c   Connect only, do not read or write.

       -v   Enable verbose mode.

       -?   Display usage message and exit.

DIAGNOSTICS         top

       If telnet-probe succeeds, then 0 will be returned.  If the attempt to
       establish a connection fails or is terminated, then a non-zero exit
       status is returned.


       Environment variables with the prefix PCP_ are used to parameterize
       the file and directory names used by PCP.  On each installation, the
       file /etc/pcp.conf contains the local values for these variables.
       The $PCP_CONF variable may be used to specify an alternative
       configuration file, as described in pcp.conf(5).

SEE ALSO         top

       PCPIntro(1), pmdashping(1), pmie(1), telnet(1), connect(2), read(2)
       and write(2).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at ⟨⟩.
       If you have a bug report for this manual page, send it to  This page was obtained from the project's upstream
       Git repository ⟨⟩ on
       2020-11-01.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-10-30.)  If you discover any
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       (which is not part of the original manual page), send a mail to

Performance Co-Pilot                 PCP                     TELNET-PROBE(1)