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

NNAAMMEE
     tteellnneett — user interface to the TELNET
     protocol

SSYYNNOOPPSSIISS
     tteellnneett [--88EEFFKKLLaaccddffrrxx]
     [--SS _t_o_s] [--XX _a_u_t_h_t_y_p_e]
     [--ee _e_s_c_a_p_e_c_h_a_r] [--kk
     _r_e_a_l_m]
            [--ll _u_s_e_r] [--nn
            _t_r_a_c_e_f_i_l_e] [_h_o_s_t
            [_p_o_r_t]]

DDEESSCCRRIIPPTTIIOONN
     The tteellnneett command is used to communicate
     with another host using the TELNET protocol.  If
     tteellnneett is invoked without the _h_o_s_t
     argument, it enters command mode, indicated by its prompt
     (tteellnneett>>).  In this mode, it accepts and
     executes the commands listed below.  If it is invoked
     with arguments, it performs an ooppeenn command with
     those arguments.

     Options:

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

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

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

     --KK      Specifies no automatic login to the remote
     system.

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

     --NN      Prevents IP address to name lookup when
     destination host is given
             as an IP address.

     --SS _t_o_s  Sets the IP type-of-service (TOS)
     option for the telnet connec‐
             tion to the value _t_o_s_, which can
             be a numeric TOS value or, on systems that
             support it, a symbolic TOS name found in the
             _/_e_t_c_/_i_p_t_o_s file.

     --XX _a_t_y_p_e
             Disables the _a_t_y_p_e type of
             authentication.

     --a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.

     --cc      Disables the reading of the user's
     _._t_e_l_n_e_t_r_c file.  (See the
             ttooggggllee sskkiipprrcc command
             on this man page.)

     --dd      Sets the initial value of the ddeebbuugg
     toggle to TRUE.

     --ee _e_s_c_a_p_e_c_h_a_r
             Sets the initial tteellnneett escape
             character to _e_s_c_a_p_e_c_h_a_r.
             If _e_s_c_a_p_e_c_h_a_r is omitted,
             then there will be no escape character.

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

     --kk _r_e_a_l_m
             If Kerberos authentication is being used, the
             --kk option requests that tteellnneett
             obtain tickets for the remote host in realm
             _r_e_a_l_m instead of the remote host's
             realm, as determined by krb_realmofhost(3).

     --ll _u_s_e_r
             When connecting to the remote system, if the
             remote system under‐ stands the ENVIRON option,
             then _u_s_e_r will be sent to the remote
             system as the value for the variable USER.  This
             option implies the --aa option.  This option may
             also be used with the ooppeenn com‐ mand.

     --nn _t_r_a_c_e_f_i_l_e
             Opens _t_r_a_c_e_f_i_l_e for
             recording trace information.  See the sseett
             ttrraacceeffiillee command below.

     --r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e option.

     --xx      Turns on encryption of the data stream
     if possible.  This option
             is not available outside of the United States
             and Canada.

     _h_o_s_t    Indicates the official name, an alias,
     or the Internet address of
             a remote host.

     _p_o_r_t    Indicates a port number (address of
     an application).  If a number
             is not specified, the default tteellnneett
             port is used.

     When in rlogin mode, a line of the form ~.  disconnects
     from the remote host; ~ is the tteellnneett
     escape character.  Similarly, the line ~^Z suspends the
     tteellnneett session.  The line ~^] escapes to
     the normal tteellnneett escape prompt.

     Once a connection has been opened, tteellnneett
     will attempt to enable the TELNET LINEMODE option.
     If this fails, then tteellnneett 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 char‐ acter echoing is
     to be disabled, the remote system will relay that infor‐
     mation.  The remote system will also relay changes to any
     special charac‐ ters 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 char‐ acter”
     (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
     llooccaallcchhaarrss toggle is TRUE (the
     default for “old line by line”; see below), the user's
     qquuiitt, iinnttrr, and fflluusshh characters
     are trapped locally, and sent as TELNET protocol sequences
     to the remote side.  If LINEMODE has ever been enabled,
     then the user's ssuusspp and eeooff are also sent
     as TELNET protocol sequences, and qquuiitt is sent
     as a TELNET ABORT instead of BREAK.  There are options
     (see ttooggggllee aauuttoofflluusshh and
     ttooggggllee aauuttoossyynncchh below)
     which cause this action to flush subsequent output to
     the terminal (until the remote host acknowl‐ edges
     the TELNET sequence) and flush previous terminal input
     (in the case of qquuiitt and iinnttrr).

     While connected to a remote host, tteellnneett
     command mode may be entered by typing the
     tteellnneett “escape character” (initially
     “^]”).  When in command mode, the normal terminal
     editing conventions are available.

     The following tteellnneett commands are available.
     Only enough of each command to uniquely identify
     it need be typed (this is also true for arguments
     to the mmooddee, sseett, ttooggggllee,
     uunnsseett, ssllcc, eennvviirroonn,
     and ddiissppllaayy commands).

     aauutthh _a_r_g_u_m_e_n_t _._._.
                The auth command manipulates the information
                sent through the TELNET AUTHENTICATE option.
                Valid arguments for the aauutthh com‐
                mand are:

                ddiissaabbllee _t_y_p_e  Disables
                the specified type of authentication.
                              To obtain a list of available
                              types, use the aauutthh
                              ddiissaabbllee
                              ?? command.

                eennaabbllee _t_y_p_e   Enables
                the specified type of authentication.
                              To obtain a list of available
                              types, use the aauutthh
                              eennaabbllee ?? command.

                ssttaattuuss        Lists the current
                status of the various types of
                              authentication.

     cclloossee      Close a TELNET session and return
     to command mode.

     ddiissppllaayy _a_r_g_u_m_e_n_t _._._.
                Displays all, or some, of the sseett and
                ttooggggllee values (see below).

     eennccrryypptt _a_r_g_u_m_e_n_t _._._.
                The encrypt command manipulates the information
                sent through the TELNET ENCRYPT option.

                Note:  Because of export controls, the TELNET
                ENCRYPT option is not supported outside of
                the United States and Canada.

                Valid arguments for the eennccrryypptt
                command are:

                ddiissaabbllee _t_y_p_e
                [[iinnppuutt||oouuttppuutt]]
                              Disables the specified type
                              of encryption.  If you omit the
                              input and output, both input and
                              output are disabled.  To obtain
                              a list of avail‐ able types,
                              use the eennccrryypptt
                              ddiissaabbllee
                              ?? command.

                eennaabbllee _t_y_p_e
                [[iinnppuutt||oouuttppuutt]]
                              Enables the specified type
                              of encryption.  If you omit
                              input and output, both input and
                              output are enabled.  To obtain
                              a list of available types,
                              use the eennccrryypptt
                              eennaabbllee ?? command.

                iinnppuutt         This is the same as
                the eennccrryypptt ssttaarrtt
                iinnppuutt com‐
                              mand.

                --iinnppuutt        This is the same
                as the eennccrryypptt ssttoopp
                iinnppuutt com‐
                              mand.

                oouuttppuutt        This is the same
                as the eennccrryypptt ssttaarrtt
                oouuttppuutt
                              command.

                --oouuttppuutt       This is the same
                as the eennccrryypptt ssttoopp
                oouuttppuutt com‐
                              mand.

                ssttaarrtt
                [[iinnppuutt||oouuttppuutt]]
                              Attempts to start encryption.
                              If you omit iinnppuutt
                              and oouuttppuutt,, both
                              input and output are enabled.  To
                              obtain a list of available types,
                              use the eennccrryypptt
                              eennaabbllee ?? command.

                ssttaattuuss        Lists the current
                status of encryption.

                ssttoopp
                [[iinnppuutt||oouuttppuutt]]
                              Stops encryption.  If you omit
                              input and output, encryption
                              is on both input and output.

                ttyyppee _t_y_p_e     Sets the default
                type of encryption to be used
                              with later eennccrryypptt
                              ssttaarrtt or
                              eennccrryypptt
                              ssttoopp com‐ mands.

     eennvviirroonn _a_r_g_u_m_e_n_t_s_._._.
                The eennvviirroonn command is used
                to manipulate the variables that my 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a or --ll options are used.

                Valid arguments for the eennvviirroonn
                command are:

                ddeeffiinnee _v_a_r_i_a_b_l_e
                _v_a_l_u_e
                            Define the variable
                            _v_a_r_i_a_b_l_e to have
                            a value of _v_a_l_u_e_. Any
                            variables defined by this command
                            are automatically exported.
                            The _v_a_l_u_e may be enclosed
                            in single or double quotes so that
                            tabs and spaces may be included.

                uunnddeeffiinnee
                _v_a_r_i_a_b_l_e
                            Remove _v_a_r_i_a_b_l_e
                            from the list of environment
                            vari‐ ables.

                eexxppoorrtt _v_a_r_i_a_b_l_e
                            Mark the variable
                            _v_a_r_i_a_b_l_e to be
                            exported to the remote side.

                uunneexxppoorrtt
                _v_a_r_i_a_b_l_e
                            Mark the variable
                            _v_a_r_i_a_b_l_e to not
                            be exported unless explicitly
                            asked for by the remote side.

                lliisstt        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 eennvviirroonn com‐
                            mand.

     llooggoouutt     Sends the TELNET LOGOUT option
     to the remote side.  This com‐
                mand is similar to a cclloossee 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 con‐ nection.
                If the remote side also supports the concept
                of sus‐ pending a user's session for later
                reattachment, the logout argument indicates
                that you should terminate the session imme‐
                diately.

     mmooddee _t_y_p_e  _T_y_p_e 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.

                cchhaarraacctteerr     Disable the
                TELNET LINEMODE option, or, if the
                              remote side does not understand
                              the LINEMODE option, then enter
                              “character at a time” mode.

                lliinnee          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.

                iissiigg (--iissiigg)  Attempt to
                enable (disable) the TRAPSIG mode of
                              the LINEMODE option.  This
                              requires that the LINEMODE
                              option be enabled.

                eeddiitt (--eeddiitt)  Attempt to
                enable (disable) the EDIT mode of the
                              LINEMODE option.  This requires
                              that the LINEMODE option
                              be enabled.

                ssooffttttaabbss
                (--ssooffttttaabbss)
                              Attempt to enable (disable) the
                              SOFT_TAB mode of the LINEMODE
                              option.  This requires that
                              the LINEMODE option be enabled.

                lliitteecchhoo
                (--lliitteecchhoo)
                              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 mmooddee com‐
                              mand.

     ooppeenn _h_o_s_t [--ll _u_s_e_r] [[--]
     _p_o_r_t]
                Open a connection to the named host.  If no
                port number is specified, tteellnneett
                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l
                option may be used to specify the user
                name to be passed to the remote system via
                the ENVIRON option.  When connecting to a
                non-standard port, tteellnneett 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
                _._t_e_l_n_e_t_r_c in the users home
                directory is opened.  Lines beginning with a #
                are comment lines.  Blank lines are ignored.
                Lines that begin without white space 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 white
                space are assumed to be tteellnneett
                commands and are processed as if they had been
                typed in manually to the tteellnneett
                command prompt.

     qquuiitt       Close any open TELNET session and
     exit tteellnneett.  An end of file
                (in command mode) will also close a session
                and exit.

     sseenndd _a_r_g_u_m_e_n_t_s
                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):

                aabboorrtt   Sends the TELNET ABORT
                (Abort processes) sequence.

                aaoo      Sends the TELNET AO (Abort Output)
                sequence, which
                        should cause the remote system to flush
                        all output _f_r_o_m the remote
                        system _t_o the user's terminal.

                aayytt     Sends the TELNET AYT (Are You
                There) sequence, to
                        which the remote system may or may
                        not choose to respond.

                bbrrkk     Sends the TELNET BRK (Break)
                sequence, which may have
                        significance to the remote system.

                eecc      Sends the TELNET EC (Erase
                Character) sequence, which
                        should cause the remote system to
                        erase the last char‐ acter entered.

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

                eeooff     Sends the TELNET EOF (End Of
                File) sequence.

                eeoorr     Sends the TELNET EOR (End of
                Record) sequence.

                eessccaappee  Sends the current
                tteellnneett escape character (initially
                        “^”).

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

                ggeettssttaattuuss
                        If the remote side supports
                        the TELNET STATUS command,
                        ggeettssttaattuuss will send
                        the subnegotiation to request that the
                        server send its current option status.

                iipp      Sends the TELNET IP (Interrupt
                Process) sequence,
                        which should cause the remote system
                        to abort the cur‐ rently running
                        process.

                nnoopp     Sends the TELNET NOP (No
                OPeration) sequence.

                ssuusspp    Sends the TELNET SUSP (SUSPend
                process) sequence.

                ssyynncchh   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 terminal).

                ddoo _c_m_d

                ddoonntt _c_m_d

                wwiillll _c_m_d

                wwoonntt _c_m_d
                        Sends the TELNET DO _c_m_d
                        sequence.  _C_m_d can be either
                        a decimal number between 0 and 255,
                        or a symbolic name for a specific
                        TELNET command.  _C_m_d can also be
                        either hheellpp or ?? to print
                        out help information, including a
                        list of known symbolic names.

                ??       Prints out help information for
                the sseenndd command.

     sseett _a_r_g_u_m_e_n_t _v_a_l_u_e

     uunnsseett _a_r_g_u_m_e_n_t _v_a_l_u_e
                The sseett command will set any one of a
                number of tteellnneett vari‐ ables to a
                specific value or to TRUE.  The special value
                ooffff turns off the function associated
                with the variable, this is equivalent
                to using the uunnsseett command.
                The uunnsseett command will disable or
                set to FALSE any of the specified functions.
                The values of variables may be interrogated
                with the ddiissppllaayy com‐ mand.
                The variables which may be set or unset, but
                not tog‐ gled, are listed here.  In addition,
                any of the variables for the ttooggggllee
                command may be explicitly set or unset using
                the sseett and uunnsseett commands.

                aayytt     If TELNET is in localchars mode,
                or LINEMODE is
                        enabled, and the status character
                        is typed, a TELNET AYT sequence (see
                        sseenndd aayytt preceding) is
                        sent to the remote host.  The initial
                        value for the “Are You There”
                        character is the terminal's status
                        character.

                eecchhoo    This is the value (initially
                “^E”) which, when in
                        “line by line” mode, toggles
                        between doing local echo‐ ing
                        of entered characters (for normal
                        processing), and suppressing echoing
                        of entered characters (for enter‐
                        ing, say, a password).

                eeooff     If tteellnneett is
                operating in LINEMODE or “old line by
                        line” mode, entering this character
                        as the first char‐ acter 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 eeooff character.

                eerraassee   If tteellnneett
                is in llooccaallcchhaarrss
                mode (see ttooggggllee
                llooccaallcchhaarrss
                        below), aanndd if tteellnneett
                        is operating in “character at a
                        time” mode, then when this character
                        is typed, a TELNET EC sequence (see
                        sseenndd eecc above) is sent to
                        the remote system.  The initial value
                        for the erase char‐ acter is taken
                        to be the terminal's eerraassee
                        character.

                eessccaappee  This is the
                tteellnneett escape character (initially
                “^[”)
                        which causes entry into
                        tteellnneett command mode (when
                        con‐ nected to a remote system).

                fflluusshhoouuttppuutt
                        If tteellnneett is in
                        llooccaallcchhaarrss
                        mode (see ttooggggllee
                        llooccaallcchhaarrss
                        below) and the
                        fflluusshhoouuttppuutt
                        character is typed, a TELNET AO
                        sequence (see sseenndd aaoo
                        above) is sent to the remote host.
                        The initial value for the flush
                        charac‐ ter is taken to be the
                        terminal's fflluusshh character.

                ffoorrww11

                ffoorrww22   If tteellnneett 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 termi‐ nal's eol
                        and eol2 characters.

                iinntteerrrruupptt
                        If tteellnneett is in
                        llooccaallcchhaarrss
                        mode (see ttooggggllee
                        llooccaallcchhaarrss below)
                        and the iinntteerrrruupptt
                        character is typed, a TELNET IP
                        sequence (see sseenndd iipp
                        above) is sent to the remote host.
                        The initial value for the interrupt
                        character is taken to be the terminal's
                        iinnttrr character.

                kkiillll    If tteellnneett
                is in llooccaallcchhaarrss
                mode (see ttooggggllee
                llooccaallcchhaarrss
                        below), aanndd if tteellnneett
                        is operating in “character at a
                        time” mode, then when this character
                        is typed, a TELNET EL sequence (see
                        sseenndd eell above) is sent to
                        the remote system.  The initial value
                        for the kill charac‐ ter is taken
                        to be the terminal's kkiillll
                        character.

                llnneexxtt   If tteellnneett is
                operating in LINEMODE or “old line by
                        line” mode, then this character
                        is taken to be the terminal's
                        llnneexxtt character.  The initial
                        value for the lnext character is taken
                        to be the terminal's llnneexxtt
                        character.

                qquuiitt    If tteellnneett
                is in llooccaallcchhaarrss
                mode (see ttooggggllee
                llooccaallcchhaarrss
                        below) and the qquuiitt character
                        is typed, a TELNET BRK sequence (see
                        sseenndd bbrrkk above) is sent
                        to the remote host.  The initial value
                        for the quit character is taken to be
                        the terminal's qquuiitt character.

                rreepprriinntt
                        If tteellnneett is operating
                        in LINEMODE or “old line by line”
                        mode, then this character is taken to
                        be the terminal's rreepprriinntt
                        character.  The initial value for
                        the reprint character is taken to be
                        the terminal's rreepprriinntt
                        character.

                rrllooggiinn  This is the rlogin escape
                character.  If set, the nor‐
                        mal tteellnneett 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 followed by a ^Z it suspends
                        the tteellnneett command.
                        The initial state is to disable the
                        rrllooggiinn escape character.

                ssttaarrtt   If the TELNET
                TOGGLE-FLOW-CONTROL option has been
                        enabled, then this character is
                        taken to be the termi‐ nal's
                        ssttaarrtt character.  The initial
                        value for the start character is taken
                        to be the terminal's ssttaarrtt
                        character.

                ssttoopp    If the TELNET
                TOGGLE-FLOW-CONTROL option has been
                        enabled, then this character is taken
                        to be the termi‐ nal's ssttoopp
                        character.  The initial value for
                        the stop character is taken to be the
                        terminal's ssttoopp charac‐ ter.

                ssuusspp    If tteellnneett is
                in llooccaallcchhaarrss mode,
                or LINEMODE is
                        enabled, and the ssuussppeenndd
                        character is typed, a TELNET SUSP
                        sequence (see sseenndd ssuusspp
                        above) is sent to the remote host.
                        The initial value for the suspend
                        char‐ acter is taken to be the
                        terminal's ssuussppeenndd
                        character.

                ttrraacceeffiillee
                        This is the file to which the output,
                        caused by nneettddaattaa or
                        ooppttiioonn tracing being TRUE,
                        will be written.  If it is set to
                        “--”, then tracing information
                        will be written to standard output
                        (the default).

                wwoorrddeerraassee
                        If tteellnneett is operating
                        in LINEMODE or “old line by
                        line” mode, then this character
                        is taken to be the terminal's
                        wwoorrddeerraassee character.
                        The initial value for the worderase
                        character is taken to be the terminal's
                        wwoorrddeerraassee character.

                ??       Displays the legal sseett
                (uunnsseett) commands.

     ssllcc _s_t_a_t_e  The ssllcc 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 iipp or qquuiitt) or line
                editing characters (like eerraassee
                and kkiillll).  By default, the local
                special characters are exported.

                cchheecckk       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.

                eexxppoorrtt      Switch to the local
                defaults for the special char‐
                            acters.  The local default
                            characters are those of the
                            local terminal at the time when
                            tteellnneett was started.

                iimmppoorrtt      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 ssllcc command.

     ssttaattuuss     Show the current status of
     tteellnneett.  This includes the peer one
                is connected to, as well as the current mode.

     ttooggggllee _a_r_g_u_m_e_n_t_s _._._.
                Toggle (between TRUE and FALSE) various flags
                that control how tteellnneett responds
                to events.  These flags may be set explicitly
                to TRUE or FALSE using the sseett and
                uunnsseett commands listed above.
                More than one argument may be specified.
                The state of these flags may be interrogated
                with the ddiissppllaayy command.
                Valid arguments are:

                aauutthhddeebbuugg     Turns on
                debugging information for the authenti‐
                              cation code.

                aauuttoofflluusshh     If
                aauuttoofflluusshh and
                llooccaallcchhaarrss are both
                TRUE, then
                              when the aaoo, or qquuiitt
                              characters are recognized
                              (and transformed into TELNET
                              sequences; see sseett above
                              for details), tteellnneett
                              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)).

                aauuttooddeeccrryypptt   When the
                TELNET ENCRYPT option is negotiated, by
                              default the actual encryption
                              (decryption) of the data stream
                              does not start automatically.
                              The autoencrypt (autodecrypt)
                              command states that encryption of
                              the output (input) stream should
                              be enabled as soon as possible.

                              Note:  Because of export
                              controls, the TELNET ENCRYPT
                              option is not supported outside
                              the United States and Canada.

                aauuttoollooggiinn     If the remote
                side supports the TELNET
                              AUTHENTICATION option
                              tteellnneett 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a option on
                              the ooppeenn command.

                aauuttoossyynncchh     If
                aauuttoossyynncchh and
                llooccaallcchhaarrss are both
                TRUE, then
                              when either the iinnttrr
                              or qquuiitt characters is
                              typed (see sseett above for
                              descriptions of the iinnttrr
                              and qquuiitt characters),
                              the resulting TELNET sequence
                              sent is followed by the TELNET
                              SYNCH sequence.  This procedure
                              sshhoouulldd 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.

                bbiinnaarryy        Enable or disable
                the TELNET BINARY option on
                              both input and output.

                iinnbbiinnaarryy      Enable or
                disable the TELNET BINARY option on
                              input.

                oouuttbbiinnaarryy     Enable or
                disable the TELNET BINARY option on
                              output.

                ccrrllff          If this is TRUE, then
                carriage returns will be
                              sent as <CR><LF>.  If this is
                              FALSE, then car‐ riage returns
                              will be send as <CR><NUL>.
                              The initial value for this
                              toggle is FALSE.

                ccrrmmoodd         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 feed.  The initial
                              value for this toggle is FALSE.

                ddeebbuugg         Toggles socket level
                debugging (useful only to
                              the ssuuppeerr
                              uusseerr).  The initial
                              value for this toggle is FALSE.

                eennccddeebbuugg      Turns on
                debugging information for the encryp‐
                              tion code.

                llooccaallcchhaarrss    If
                this is TRUE, then the fflluusshh,
                iinntteerrrruupptt,
                              qquuiitt, eerraassee,
                              and kkiillll characters (see
                              sseett above) are recognized
                              locally, and transformed into
                              (hopefully) appropriate TELNET
                              control sequences (respectively
                              aaoo, iipp, bbrrkk,
                              eecc, and eell; see
                              sseenndd 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
                              llooccaallcchhaarrss is
                              ignored, and assumed to always
                              be TRUE.  If LINEMODE has ever
                              been enabled, then qquuiitt
                              is sent as aabboorrtt,
                              and eeooff aanndd
                              ssuussppeenndd are sent as
                              eeooff aanndd ssuusspp
                              (see sseenndd above).

                nneettddaattaa       Toggles the
                display of all network data (in
                              hexadecimal format).  The initial
                              value for this toggle is FALSE.

                ooppttiioonnss       Toggles the display
                of some internal tteellnneett pro‐
                              tocol processing (having
                              to do with TELNET options).
                              The initial value for this
                              toggle is FALSE.

                pprreettttyydduummpp    When the
                nneettddaattaa toggle is enabled, if
                              pprreettttyydduummpp
                              is enabled the output from the
                              nneettddaattaa command
                              will be formatted in a more user
                              readable format.  Spaces are put
                              between each character in the
                              output, and the beginning of
                              any tteellnneett escape
                              sequence is preceded by a '*'
                              to aid in locating them.

                sskkiipprrcc        When the skiprc
                toggle is TRUE, tteellnneett skips the
                              reading of the
                              _._t_e_l_n_e_t_r_c file
                              in the users home directory
                              when connections are opened.
                              The ini‐ tial value for this
                              toggle is FALSE.

                tteerrmmddaattaa      Toggles the
                display of all terminal data (in
                              hexadecimal format).  The initial
                              value for this toggle is FALSE.

                vveerrbboossee__eennccrryypptt
                              When the
                              vveerrbboossee__eennccrryypptt
                              toggle is TRUE,
                              tteellnneett prints out a
                              message each time encryption
                              is enabled or disabled.
                              The initial value for this
                              toggle is FALSE. Note:  Because
                              of export con‐ trols, data
                              encryption is not supported
                              outside of the United States
                              and Canada.

                ??             Displays the legal
                ttooggggllee commands.

     zz          Suspend tteellnneett.  This command
     only works when the user is
                using the csh(1).

     !! [_c_o_m_m_a_n_d]
                Execute a single command in a subshell on
                the local system.  If _c_o_m_m_a_n_d
                is omitted, then an interactive subshell
                is invoked.

     ?? [_c_o_m_m_a_n_d]
                Get help.  With no arguments,
                tteellnneett prints a help summary.
                If _c_o_m_m_a_n_d is specified,
                tteellnneett will print the help
                informa‐ tion for just that command.

EENNVVIIRROONNMMEENNTT
     tteellnneett uses at least the HOME, SHELL, DISPLAY,
     and TERM environment vari‐ ables.  Other environment
     variables may be propagated to the other side via the
     TELNET ENVIRON option.

SSEEEE AALLSSOO
     rlogin(1), rsh(1), hosts(5), nologin(5), telnetd(8)

FFIILLEESS
     ~/.telnetrc  user customized telnet startup values

HHIISSTTOORRYY
     The tteellnneett command appeared in 4.2BSD.

NNOOTTEESS
     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
     eeooff character is only recognized (and sent to the
     remote system) when it is the first character on a line.

4.2 Berkeley Distribution        March 1, 1994       4.2
Berkeley Distribution
