TELNET linux command manual

TELNET(1)           BSD General Commands Manual                TELNET(1)

NAME
     telnet - user interface to the TELNET protocol

SYNOPSIS
     telnet [-8EFKLacdfrx] [-X authtype] [-b hostalias] [-e escapechar]
            [-k realm] [-l user] [-n tracefile] [host [port]]

DESCRIPTION
     The telnet command is used to communicate with another host using the
     TELNET protocol.  If telnet is invoked without the host argument, it
     enters command mode, indicated by its prompt (telnet>).  In this mode,
     it accepts and executes the commands listed below.  If it is invoked
     with arguments, it performs an open command with those arguments.

     The options are as follows:

     -7      Strip 8th bit on input and output. Telnet is 8-bit clean by
             default but doesn't send the TELNET BINARY option unless forced.

     -8      Specifies an 8-bit data path.  This causes an attempt to negoti-
             ate the TELNET BINARY option on both input and output.

     -E      Stops any character from being recognized as an escape charac-
             ter.

     -F      If Kerberos V5 authentication is being used, the -F option
             allows the local credentials to be forwarded to the remote sys-
             tem, including any credentials that have already been forwarded
             into the local environment.

     -K      Specifies no automatic login to the remote system.

     -L      Specifies an 8-bit data path on output.  This causes the BINARY
             option to be negotiated on output.

     -X atype
             Disables the atype type of authentication.

     -a      Attempt automatic login.  Currently, this sends the user name
             via the USER variable of the ENVIRON option if supported by the
             remote system.  The name used is that of the current user as
             returned by getlogin(2) if it agrees with the current user ID,
             otherwise it is the name associated with the user ID.

     -b hostalias
             Uses bind(2) on the local socket to bind it to an aliased
             address (see ifconfig(8) and the ''alias'' specifier) or to the
             address of another interface than the one naturally chosen by
             connect(2).  This can be useful when connecting to services
             which use IP addresses for authentication and reconfiguration of
             the server is undesirable (or impossible).

     -c      Disables the reading of the user's .telnetrc file.  (See the
             toggle skiprc command on this man page.)

     -d      Sets the initial value of the debug toggle to TRUE.

     -e escapechar
             Sets the initial telnet escape character to escapechar.  If
             escapechar is omitted, then there will be no escape character.

     -f      If Kerberos V5 authentication is being used, the -f option
             allows the local credentials to be forwarded to the remote sys-
             tem.

     -k realm
             If Kerberos authentication is being used, the -k option requests
             that telnet obtain tickets for the remote host in realm realm
             instead of the remote host's realm, as determined by
             krb_realmofhost(3).

     -l user
             When connecting to the remote system, if the remote system
             understands the ENVIRON option, then user will be sent to the
             remote system as the value for the variable USER.  This option
             implies the -a option.  This option may also be used with the
             open command.

     -n tracefile
             Opens tracefile for recording trace information.  See the set
             tracefile command below.

     -r      Specifies a user interface similar to rlogin(1).  In this mode,
             the escape character is set to the tilde (~) character, unless
             modified by the -e option.

     -x      Turns on encryption of the data stream if possible.

     host    Indicates the official name, an alias, or the Internet address
             of a remote host.

     port    Indicates a port number (address of an application).  If a num-
             ber is not specified, the default telnet port is used.

     When in rlogin mode, a line of the form ~.  disconnects from the remote
     host; ~ is the telnet escape character.  Similarly, the line ~^Z sus-
     pends the telnet session.  The line ~^] escapes to the normal telnet
     escape prompt.

     Once a connection has been opened, telnet will attempt to enable the
     TELNET LINEMODE option.  If this fails, telnet will revert to one of two
     input modes: either ''character at a time'' or ''old line by line''
     depending on what the remote system supports.

     When LINEMODE is enabled, character processing is done on the local sys-
     tem, under the control of the remote system.  When input editing or
     character echoing is to be disabled, the remote system will relay that
     information.  The remote system will also relay changes to any special
     characters that happen on the remote system, so that they can take
     effect on the local system.

     In ''character at a time'' mode, most text typed is immediately sent to
     the remote host for processing.

     In ''old line by line'' mode, all text is echoed locally, and (normally)
     only completed lines are sent to the remote host.  The ''local echo
     character'' (initially ''^E'') may be used to turn off and on the local
     echo (this would mostly be used to enter passwords without the password
     being echoed).

     If the LINEMODE option is enabled, or if the localchars toggle is TRUE
     (the default for ''old line by line''; see below), the user's quit,
     intr, and flush characters are trapped locally, and sent as TELNET pro-
     tocol sequences to the remote side.  If LINEMODE has ever been enabled,
     then the user's susp and eof are also sent as TELNET protocol sequences,
     and quit is sent as a TELNET ABORT instead of BREAK.  There are options
     (see toggle autoflush and toggle autosynch below) which cause this
     action to flush subsequent output to the terminal (until the remote host
     acknowledges the TELNET sequence) and flush previous terminal input (in
     the case of quit and intr).

     While connected to a remote host, telnet command mode may be entered by
     typing the telnet ''escape character'' (initially ''^]'').  When in com-
     mand mode, the normal terminal editing conventions are available.  Note
     that the escape character will return to the command mode of the initial
     invocation of telnet that has the controlling terminal.  Use the send
     escape command to switch to command mode in subsequent telnet processes
     on remote hosts.

     The following telnet commands are available.  Only enough of each com-
     mand to uniquely identify it need be typed (this is also true for argu-
     ments to the mode, set, toggle, unset, slc, environ, and display com-
     mands).

     auth argument [...]
                The auth command manipulates the information sent through the
                TELNET AUTHENTICATE option.  Valid arguments for the auth
                command are as follows:

                disable type  Disables the specified type of authentication.
                              To obtain a list of available types, use the
                              auth disable ? command.

                enable type   Enables the specified type of authentication.
                              To obtain a list of available types, use the
                              auth enable ? command.

                status        Lists the current status of the various types
                              of authentication.

     close      Close a TELNET session and return to command mode.

     display argument [...]
                Displays all, or some, of the set and toggle values (see
                below).

     encrypt argument [...]
                The encrypt command manipulates the information sent through
                the TELNET ENCRYPT option.

                Valid arguments for the encrypt command are as follows:

                disable type [input|output]
                              Disables the specified type of encryption.  If
                              you omit input and output, both input and out-
                              put are disabled.  To obtain a list of avail-
                              able types, use the encrypt disable ? command.

                enable type [input|output]
                              Enables the specified type of encryption.  If
                              you omit input and output, both input and out-
                              put are enabled.  To obtain a list of available
                              types, use the encrypt enable ? command.

                input         This is the same as the encrypt start input
                              command.

                -input        This is the same as the encrypt stop input com-
                              mand.

                output        This is the same as the encrypt start output
                              command.

                -output       This is the same as the encrypt stop output
                              command.

                start [input|output]
                              Attempts to start encryption.  If you omit
                              input and output, both input and output are
                              enabled.  To obtain a list of available types,
                              use the encrypt enable ? command.

                status        Lists the current status of encryption.

                stop [input|output]
                              Stops encryption.  If you omit input and
                              output, encryption is on both input and output.

                type type     Sets the default type of encryption to be used
                              with later encrypt start or encrypt stop com-
                              mands.

     environ arguments [...]
                The environ command is used to manipulate the variables that
                may be sent through the TELNET ENVIRON option.  The initial
                set of variables is taken from the users environment, with
                only the DISPLAY and PRINTER variables being exported by
                default.  The USER variable is also exported if the -a or -l
                options are used.
                Valid arguments for the environ command are:

                define variable value
                            Define the variable variable to have a value of
                            value.  Any variables defined by this command are
                            automatically exported.  The value may be
                            enclosed in single or double quotes so that tabs
                            and spaces may be included.

                undefine variable
                            Remove variable from the list of environment
                            variables.

                export variable
                            Mark the variable variable to be exported to the
                            remote side.

                unexport variable
                            Mark the variable variable to not be exported
                            unless explicitly asked for by the remote side.

                list        List the current set of environment variables.
                            Those marked with a * will be sent automatically,
                            other variables will only be sent if explicitly
                            requested.

                ?           Prints out help information for the environ com-
                            mand.

     logout     Sends the TELNET LOGOUT option to the remote side.  This com-
                mand is similar to a close command; however, if the remote
                side does not support the LOGOUT option, nothing happens.
                If, however, the remote side does support the LOGOUT option,
                this command should cause the remote side to close the TELNET
                connection.  If the remote side also supports the concept of
                suspending a user's session for later reattachment, the
                logout argument indicates that you should terminate the ses-
                sion immediately.

     mode type  type is one of several options, depending on the state of the
                TELNET session.  The remote host is asked for permission to
                go into the requested mode.  If the remote host is capable of
                entering that mode, the requested mode will be entered.

                character     Disable the TELNET LINEMODE option, or, if the
                              remote side does not understand the LINEMODE
                              option, then enter ''character at a time''
                              mode.

                line          Enable the TELNET LINEMODE option, or, if the
                              remote side does not understand the LINEMODE
                              option, then attempt to enter ''old-line-by-
                              line'' mode.

                isig (-isig)  Attempt to enable (disable) the TRAPSIG mode of
                              the LINEMODE option.  This requires that the
                              LINEMODE option be enabled.

                edit (-edit)  Attempt to enable (disable) the EDIT mode of
                              the LINEMODE option.  This requires that the
                              LINEMODE option be enabled.

                softtabs (-softtabs)
                              Attempt to enable (disable) the SOFT_TAB mode
                              of the LINEMODE option.  This requires that the
                              LINEMODE option be enabled.

                litecho (-litecho)
                              Attempt to enable (disable) the LIT_ECHO mode
                              of the LINEMODE option.  This requires that the
                              LINEMODE option be enabled.

                ?             Prints out help information for the mode com-
                              mand.

     open host [-l user] [[-] port]
                Open a connection to the named host.  If no port number is
                specified, telnet will attempt to contact a TELNET server at
                the default port.  The host specification may be either a
                host name (see hosts(5)) or an Internet address specified in
                the ''dot notation'' (see inet(3)).  The -l option may be
                used to specify the user name to be passed to the remote sys-
                tem via the ENVIRON option.  When connecting to a non-stan-
                dard port, telnet omits any automatic initiation of TELNET
                options.  When the port number is preceded by a minus sign,
                the initial option negotiation is done.  After establishing a
                connection, the file .telnetrc in the user's home directory
                is opened.  Lines beginning with a ''#'' are comment lines.
                Blank lines are ignored.  Lines that begin without whitespace
                are the start of a machine entry.  The first thing on the
                line is the name of the machine that is being connected to.
                The rest of the line, and successive lines that begin with
                whitespace are assumed to be telnet commands and are pro-
                cessed as if they had been typed in manually to the telnet
                command prompt.

     quit       Close any open TELNET session and exit telnet.  An end-of-
                file (in command mode) will also close a session and exit.

     send arguments
                Sends one or more special character sequences to the remote
                host.  The following are the arguments which may be specified
                (more than one argument may be specified at a time):

                abort   Sends the TELNET ABORT (Abort processes) sequence.

                ao      Sends the TELNET AO (Abort Output) sequence, which
                        should cause the remote system to flush all output
                        from the remote system to the user's terminal.

                ayt     Sends the TELNET AYT (Are You There) sequence, to
                        which the remote system may or may not choose to
                        respond.

                brk     Sends the TELNET BRK (Break) sequence, which may have
                        significance to the remote system.

                ec      Sends the TELNET EC (Erase Character) sequence, which
                        should cause the remote system to erase the last
                        character entered.

                el      Sends the TELNET EL (Erase Line) sequence, which
                        should cause the remote system to erase the line cur-
                        rently being entered.

                eof     Sends the TELNET EOF (End Of File) sequence.

                eor     Sends the TELNET EOR (End of Record) sequence.

                escape  Sends the current telnet escape character (initially
                        ''^]'').

                ga      Sends the TELNET GA (Go Ahead) sequence, which likely
                        has no significance to the remote system.

                getstatus
                        If the remote side supports the TELNET STATUS com-
                        mand, getstatus will send the subnegotiation to
                        request that the server send its current option sta-
                        tus.

                ip      Sends the TELNET IP (Interrupt Process) sequence,
                        which should cause the remote system to abort the
                        currently running process.

                nop     Sends the TELNET NOP (No OPeration) sequence.

                susp    Sends the TELNET SUSP (SUSPend process) sequence.

                synch   Sends the TELNET SYNCH sequence.  This sequence
                        causes the remote system to discard all previously
                        typed (but not yet read) input.  This sequence is
                        sent as TCP urgent data (and may not work if the
                        remote system is a 4.2BSD system -- if it doesn't
                        work, a lower case ''r'' may be echoed on the termi-
                        nal).

                do cmd  Sends the TELNET DO cmd sequence.  cmd can be either
                        a decimal number between 0 and 255, or a symbolic
                        name for a specific TELNET command.  cmd can also be
                        either help or ? to print out help information,
                        including a list of known symbolic names.

                dont cmd
                        Sends the TELNET DONT cmd sequence.  cmd can be
                        either a decimal number between 0 and 255, or a sym-
                        bolic name for a specific TELNET command.  cmd can
                        also be either help or ? to print out help informa-
                        tion, including a list of known symbolic names.

                will cmd
                        Sends the TELNET WILL cmd sequence.  cmd can be
                        either a decimal number between 0 and 255, or a sym-
                        bolic name for a specific TELNET command.  cmd can
                        also be either help or ? to print out help informa-
                        tion, including a list of known symbolic names.

                wont cmd
                        Sends the TELNET WONT cmd sequence.  cmd can be
                        either a decimal number between 0 and 255, or a sym-
                        bolic name for a specific TELNET command.  cmd can
                        also be either help or ? to print out help informa-
                        tion, including a list of known symbolic names.

                ?       Prints out help information for the send command.

     set argument value

     unset argument value
                The set command will set any one of a number of telnet vari-
                ables to a specific value or to TRUE.  The special value off
                turns off the function associated with the variable; this is
                equivalent to using the unset command.  The unset command
                will disable or set to FALSE any of the specified functions.
                The values of variables may be interrogated with the display
                command.  The variables which may be set or unset, but not
                toggled, are listed here.  In addition, any of the variables
                for the toggle command may be explicitly set or unset using
                the set and unset commands.

                ayt     If TELNET is in localchars mode, or LINEMODE is
                        enabled, and the status character is typed, a TELNET
                        AYT sequence (see send ayt preceding) is sent to the
                        remote host.  The initial value for the "Are You
                        There" character is the terminal's status character.

                echo    This is the value (initially ''^E'') which, when in
                        ''line by line'' mode, toggles between doing local
                        echoing of entered characters (for normal process-
                        ing), and suppressing echoing of entered characters
                        (for entering, say, a password).

                eof     If telnet is operating in LINEMODE or ''old line by
                        line'' mode, entering this character as the first
                        character on a line will cause this character to be
                        sent to the remote system.  The initial value of the
                        eof character is taken to be the terminal's eof char-
                        acter.

                erase   If telnet is in localchars mode (see toggle
                        localchars below), and if telnet is operating in
                        ''character at a time'' mode, then when this charac-
                        ter is typed, a TELNET EC sequence (see send ec
                        above) is sent to the remote system.  The initial
                        value for the erase character is taken to be the ter-
                        minal's erase character.

                escape  This is the telnet escape character (initially
                        ''^['') which causes entry into telnet command mode
                        (when connected to a remote system).

                flushoutput
                        If telnet is in localchars mode (see toggle
                        localchars below) and the flushoutput character is
                        typed, a TELNET AO sequence (see send ao above) is
                        sent to the remote host.  The initial value for the
                        flush character is taken to be the terminal's flush
                        character.

                forw1

                forw2   If TELNET is operating in LINEMODE, these are the
                        characters that, when typed, cause partial lines to
                        be forwarded to the remote system.  The initial value
                        for the forwarding characters are taken from the ter-
                        minal's eol and eol2 characters.

                interrupt
                        If telnet is in localchars mode (see toggle
                        localchars below) and the interrupt character is
                        typed, a TELNET IP sequence (see send ip above) is
                        sent to the remote host.  The initial value for the
                        interrupt character is taken to be the terminal's
                        intr character.

                kill    If telnet is in localchars mode (see toggle
                        localchars below), and if telnet is operating in
                        ''character at a time'' mode, then when this charac-
                        ter is typed, a TELNET EL sequence (see send el
                        above) is sent to the remote system.  The initial
                        value for the kill character is taken to be the ter-
                        minal's kill character.

                lnext   If telnet is operating in LINEMODE or ''old line by
                        line'' mode, then this character is taken to be the
                        terminal's lnext character.  The initial value for
                        the lnext character is taken to be the terminal's
                        lnext character.

                quit    If telnet is in localchars mode (see toggle
                        localchars below) and the quit character is typed, a
                        TELNET BRK sequence (see send brk above) is sent to
                        the remote host.  The initial value for the quit
                        character is taken to be the terminal's quit charac-
                        ter.

                reprint
                        If telnet is operating in LINEMODE or old line by
                        line'' mode, then this character is taken to be the
                        terminal's reprint character.  The initial value for
                        the reprint character is taken to be the terminal's
                        reprint character.

                rlogin  This is the rlogin escape character.  If set, the
                        normal TELNET escape character is ignored unless it
                        is preceded by this character at the beginning of a
                        line.  This character, at the beginning of a line,
                        followed by a "." closes the connection; when fol-
                        lowed by a ^Z it suspends the telnet command.  The
                        initial state is to disable the rlogin escape charac-
                        ter.

                start   If the TELNET TOGGLE-FLOW-CONTROL option has been
                        enabled, then this character is taken to be the ter-
                        minal's start character.  The initial value for the
                        start character is taken to be the terminal's start
                        character.

                stop    If the TELNET TOGGLE-FLOW-CONTROL option has been
                        enabled, then this character is taken to be the ter-
                        minal's stop character.  The initial value for the
                        stop character is taken to be the terminal's stop
                        character.

                susp    If telnet is in localchars mode, or LINEMODE is
                        enabled, and the suspend character is typed, a TELNET
                        SUSP sequence (see send susp above) is sent to the
                        remote host.  The initial value for the suspend char-
                        acter is taken to be the terminal's suspend charac-
                        ter.

                tracefile
                        This is the file to which the output, caused by
                        netdata or option tracing being TRUE, will be writ-
                        ten.  If it is set to "-", then tracing information
                        will be written to standard output (the default).

                worderase
                        If telnet is operating in LINEMODE or ''old line by
                        line'' mode, then this character is taken to be the
                        terminal's worderase character.  The initial value
                        for the worderase character is taken to be the termi-
                        nal's worderase character.

                ?       Displays the legal set (unset) commands.

     skey sequence challenge
                The skey command computes a response to the S/Key challenge.
                See skey(1) for more information on the S/Key system.

     slc state  The slc command (Set Local Characters) is used to set or
                change the state of the special characters when the TELNET
                LINEMODE option has been enabled.  Special characters are
                characters that get mapped to TELNET commands sequences (like
                ip or quit) or line editing characters (like erase and kill).
                By default, the local special characters are exported.

                check       Verify the current settings for the current spe-
                            cial characters.  The remote side is requested to
                            send all the current special character settings,
                            and if there are any discrepancies with the local
                            side, the local side will switch to the remote
                            value.

                export      Switch to the local defaults for the special
                            characters.  The local default characters are
                            those of the local terminal at the time when
                            telnet was started.

                import      Switch to the remote defaults for the special
                            characters.  The remote default characters are
                            those of the remote system at the time when the
                            TELNET connection was established.

                ?           Prints out help information for the slc command.

     status     Show the current status of telnet.  This includes the peer
                one is connected to, as well as the current mode.

     toggle arguments [...]
                Toggle (between TRUE and FALSE) various flags that control
                how telnet responds to events.  These flags may be set
                explicitly to TRUE or FALSE using the set and unset commands
                listed above.  More than one argument may be specified.  The
                state of these flags may be interrogated with the display
                command.  Valid arguments are:

                authdebug     Turns on debugging information for the authen-
                              tication code.

                autoflush     If autoflush and localchars are both TRUE, then
                              when the ao or quit characters are recognized
                              (and transformed into TELNET sequences; see set
                              above for details), telnet refuses to display
                              any data on the user's terminal until the
                              remote system acknowledges (via a TELNET TIMING
                              MARK option) that it has processed those TELNET
                              sequences.  The initial value for this toggle
                              is TRUE if the terminal user had not done an
                              "stty noflsh", otherwise FALSE (see stty(1)).

                autodecrypt   When the TELNET ENCRYPT option is negotiated,
                              by default the actual encryption (decryption)
                              of the data stream does not start automati-
                              cally.  The autoencrypt (autodecrypt) command
                              states that encryption of the output (input)
                              stream should be enabled as soon as possible.

                autologin     If the remote side supports the TELNET
                              AUTHENTICATION option TELNET attempts to use it
                              to perform automatic authentication.  If the
                              AUTHENTICATION option is not supported, the
                              user's login name are propagated through the
                              TELNET ENVIRON option.  This command is the
                              same as specifying a option on the open com-
                              mand.

                autosynch     If autosynch and localchars are both TRUE, then
                              when either the intr or quit character is typed
                              (see set above for descriptions of the intr and
                              quit characters), the resulting TELNET sequence
                              sent is followed by the TELNET SYNCH sequence.
                              This procedure should cause the remote system
                              to begin throwing away all previously typed
                              input until both of the TELNET sequences have
                              been read and acted upon.  The initial value of
                              this toggle is FALSE.

                binary        Enable or disable the TELNET BINARY option on
                              both input and output.

                inbinary      Enable or disable the TELNET BINARY option on
                              input.

                outbinary     Enable or disable the TELNET BINARY option on
                              output.

                crlf          If this is TRUE, then carriage returns will be
                              sent as .  If this is FALSE, then car-
                              riage returns will be send as .  The
                              initial value for this toggle is FALSE.

                crmod         Toggle carriage return mode.  When this mode is
                              enabled, most carriage return characters
                              received from the remote host will be mapped
                              into a carriage return followed by a line feed.
                              This mode does not affect those characters
                              typed by the user, only those received from the
                              remote host.  This mode is not very useful
                              unless the remote host only sends carriage
                              return, but never line feeds.  The initial
                              value for this toggle is FALSE.

                debug         Toggles socket level debugging (useful only to
                              the superuser).  The initial value for this
                              toggle is FALSE.

                encdebug      Turns on debugging information for the encryp-
                              tion code.

                localchars    If this is TRUE, then the flush, interrupt,
                              quit, erase, and kill characters (see set
                              above) are recognized locally, and transformed
                              into (hopefully) appropriate TELNET control
                              sequences (respectively ao, ip, brk, ec, and
                              el; see send above).  The initial value for
                              this toggle is TRUE in ''old line by line''
                              mode, and FALSE in ''character at a time''
                              mode.  When the LINEMODE option is enabled, the
                              value of localchars is ignored, and assumed to
                              always be TRUE.  If LINEMODE has ever been
                              enabled, then quit is sent as abort, and eof
                              and suspend are sent as eof and susp (see send
                              above).

                netdata       Toggles the display of all network data (in
                              hexadecimal format).  The initial value for
                              this toggle is FALSE.

                options       Toggles the display of some internal telnet
                              protocol processing (having to do with TELNET
                              options).  The initial value for this toggle is
                              FALSE.

                prettydump    When the netdata toggle is enabled, if
                              prettydump is enabled the output from the
                              netdata command will be formatted in a more
                              user readable format.  Spaces are put between
                              each character in the output, and the beginning
                              of any TELNET escape sequence is preceded by a
                              '*' to aid in locating them.

                skiprc        When the skiprc toggle is TRUE, TELNET skips
                              the reading of the .telnetrc file in the user's
                              home directory when connections are opened.
                              The initial value for this toggle is FALSE.

                termdata      Toggles the display of all terminal data (in
                              hexadecimal format).  The initial value for
                              this toggle is FALSE.

                verbose_encrypt
                              When the verbose_encrypt toggle is TRUE, telnet
                              prints out a message each time encryption is
                              enabled or disabled.  The initial value for
                              this toggle is FALSE.

                ?             Displays the legal toggle commands.

     z          Suspend telnet.  This command only works when the user is
                using the csh(1).

     ! [command]
                Execute a single command in a subshell on the local system.
                If command is omitted, then an interactive subshell is
                invoked.

     ? [command]
                Get help.  With no arguments, telnet prints a help summary.
                If a command is specified, telnet will print the help infor-
                mation for just that command.

ENVIRONMENT
     telnet uses at least the HOME, SHELL, DISPLAY, and TERM environment
     variables.  Other environment variables may be propagated to the other
     side via the TELNET ENVIRON option.

FILES
     ~/.telnetrc  user customized telnet startup values

HISTORY
     The telnet command appeared in 4.2BSD.

NOTES
     On some remote systems, echo has to be turned off manually when in ''old
     line by line'' mode.

     In ''old line by line'' mode or LINEMODE the terminal's eof character is
     only recognized (and sent to the remote system) when it is the first
     character on a line.

     Source routing is not supported yet for IPv6.

BSD                            February 3, 1994                           BSD