Annotation of src/usr.bin/telnet/telnet.1, Revision 1.6
1.6 ! lukem 1: .\" $NetBSD: telnet.1,v 1.5 1996/02/28 21:04:12 thorpej Exp $
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1.4 cgd 34: .\" from: @(#)telnet.1 8.4 (Berkeley) 2/3/94
1.1 cgd 35: .\"
1.4 cgd 36: .Dd February 3, 1994
1.1 cgd 37: .Dt TELNET 1
38: .Os BSD 4.2
39: .Sh NAME
40: .Nm telnet
1.4 cgd 41: .Nd user interface to the
1.1 cgd 42: .Tn TELNET
43: protocol
44: .Sh SYNOPSIS
45: .Nm telnet
1.4 cgd 46: .Op Fl 8
47: .Op Fl E
48: .Op Fl F
49: .Op Fl K
50: .Op Fl L
51: .Op Fl S Ar tos
52: .Op Fl X Ar authtype
53: .Op Fl a
54: .Op Fl c
1.1 cgd 55: .Op Fl d
1.4 cgd 56: .Op Fl e Ar escapechar
57: .Op Fl f
58: .Op Fl k Ar realm
59: .Op Fl l Ar user
1.1 cgd 60: .Op Fl n Ar tracefile
1.4 cgd 61: .Op Fl r
62: .Op Fl x
1.1 cgd 63: .Oo
64: .Ar host
65: .Op port
66: .Oc
67: .Sh DESCRIPTION
68: The
69: .Nm telnet
70: command
71: is used to communicate with another host using the
72: .Tn TELNET
73: protocol.
74: If
75: .Nm telnet
76: is invoked without the
77: .Ar host
78: argument, it enters command mode,
79: indicated by its prompt
80: .Pq Nm telnet\&> .
81: In this mode, it accepts and executes the commands listed below.
82: If it is invoked with arguments, it performs an
83: .Ic open
84: command with those arguments.
85: .Pp
86: Options:
87: .Bl -tag -width indent
1.4 cgd 88: .It Fl 8
89: Specifies an 8-bit data path. This causes an attempt to
90: negotiate the
91: .Dv TELNET BINARY
92: option on both input and output.
93: .It Fl E
94: Stops any character from being recognized as an escape character.
95: .It Fl F
96: If Kerberos V5 authentication is being used, the
97: .Fl F
98: option allows the local credentials to be forwarded
99: to the remote system, including any credentials that
100: have already been forwarded into the local environment.
101: .It Fl K
102: Specifies no automatic login to the remote system.
103: .It Fl L
104: Specifies an 8-bit data path on output. This causes the
105: BINARY option to be negotiated on output.
106: .It Fl S Ar tos
107: Sets the IP type-of-service (TOS) option for the telnet
108: connection to the value
109: .Ar tos,
110: which can be a numeric TOS value
111: or, on systems that support it, a symbolic
112: TOS name found in the /etc/iptos file.
113: .It Fl X Ar atype
114: Disables the
115: .Ar atype
116: type of authentication.
1.1 cgd 117: .It Fl a
118: Attempt automatic login.
119: Currently, this sends the user name via the
120: .Ev USER
121: variable
122: of the
123: .Ev ENVIRON
124: option if supported by the remote system.
125: The name used is that of the current user as returned by
126: .Xr getlogin 2
127: if it agrees with the current user ID,
128: otherwise it is the name associated with the user ID.
1.4 cgd 129: .It Fl c
130: Disables the reading of the user's
131: .Pa \&.telnetrc
132: file. (See the
133: .Ic toggle skiprc
134: command on this man page.)
135: .It Fl d
136: Sets the initial value of the
137: .Ic debug
138: toggle to
139: .Dv TRUE
140: .It Fl e Ar escape char
141: Sets the initial
142: .Nm
143: .Nm telnet
144: escape character to
145: .Ar escape char.
146: If
147: .Ar escape char
148: is omitted, then
149: there will be no escape character.
150: .It Fl f
151: If Kerberos V5 authentication is being used, the
152: .Fl f
153: option allows the local credentials to be forwarded to the remote system.
154: .It Fl k Ar realm
155: If Kerberos authentication is being used, the
156: .Fl k
157: option requests that telnet obtain tickets for the remote host in
158: realm realm instead of the remote host's realm, as determined
159: by
160: .Xr krb_realmofhost 3 .
1.1 cgd 161: .It Fl l Ar user
162: When connecting to the remote system, if the remote system
163: understands the
164: .Ev ENVIRON
165: option, then
166: .Ar user
167: will be sent to the remote system as the value for the variable USER.
168: This option implies the
169: .Fl a
170: option.
171: This option may also be used with the
172: .Ic open
173: command.
1.4 cgd 174: .It Fl n Ar tracefile
175: Opens
176: .Ar tracefile
177: for recording trace information.
178: See the
179: .Ic set tracefile
180: command below.
181: .It Fl r
182: Specifies a user interface similar to
183: .Xr rlogin 1 .
184: In this
185: mode, the escape character is set to the tilde (~) character,
186: unless modified by the -e option.
187: .It Fl x
188: Turns on encryption of the data stream if possible. This
189: option is not available outside of the United States and
190: Canada.
1.1 cgd 191: .It Ar host
192: Indicates the official name, an alias, or the Internet address
193: of a remote host.
194: .It Ar port
195: Indicates a port number (address of an application). If a number is
196: not specified, the default
197: .Nm telnet
198: port is used.
199: .El
200: .Pp
1.4 cgd 201: When in rlogin mode, a line of the form ~. disconnects from the
202: remote host; ~ is the telnet escape character.
203: Similarly, the line ~^Z suspends the telnet session.
204: The line ~^] escapes to the normal telnet escape prompt.
205: .Pp
1.1 cgd 206: Once a connection has been opened,
207: .Nm telnet
208: will attempt to enable the
209: .Dv TELNET LINEMODE
210: option.
211: If this fails, then
212: .Nm telnet
213: will revert to one of two input modes:
214: either \*(Lqcharacter at a time\*(Rq
215: or \*(Lqold line by line\*(Rq
216: depending on what the remote system supports.
217: .Pp
218: When
219: .Dv LINEMODE
220: is enabled, character processing is done on the
221: local system, under the control of the remote system. When input
222: editing or character echoing is to be disabled, the remote system
223: will relay that information. The remote system will also relay
224: changes to any special characters that happen on the remote
225: system, so that they can take effect on the local system.
226: .Pp
227: In \*(Lqcharacter at a time\*(Rq mode, most
228: text typed is immediately sent to the remote host for processing.
229: .Pp
230: In \*(Lqold line by line\*(Rq mode, all text is echoed locally,
231: and (normally) only completed lines are sent to the remote host.
232: The \*(Lqlocal echo character\*(Rq (initially \*(Lq^E\*(Rq) may be used
233: to turn off and on the local echo
234: (this would mostly be used to enter passwords
235: without the password being echoed).
236: .Pp
237: If the
238: .Dv LINEMODE
239: option is enabled, or if the
240: .Ic localchars
241: toggle is
242: .Dv TRUE
243: (the default for \*(Lqold line by line\*(Lq; see below),
244: the user's
245: .Ic quit ,
246: .Ic intr ,
247: and
248: .Ic flush
249: characters are trapped locally, and sent as
250: .Tn TELNET
251: protocol sequences to the remote side.
252: If
253: .Dv LINEMODE
254: has ever been enabled, then the user's
255: .Ic susp
256: and
257: .Ic eof
258: are also sent as
259: .Tn TELNET
260: protocol sequences,
261: and
262: .Ic quit
263: is sent as a
264: .Dv TELNET ABORT
265: instead of
266: .Dv BREAK
267: There are options (see
268: .Ic toggle
269: .Ic autoflush
270: and
271: .Ic toggle
272: .Ic autosynch
273: below)
274: which cause this action to flush subsequent output to the terminal
275: (until the remote host acknowledges the
276: .Tn TELNET
277: sequence) and flush previous terminal input
278: (in the case of
279: .Ic quit
280: and
281: .Ic intr ) .
282: .Pp
283: While connected to a remote host,
284: .Nm telnet
285: command mode may be entered by typing the
286: .Nm telnet
287: \*(Lqescape character\*(Rq (initially \*(Lq^]\*(Rq).
288: When in command mode, the normal terminal editing conventions are available.
289: .Pp
290: The following
291: .Nm telnet
292: commands are available.
293: Only enough of each command to uniquely identify it need be typed
294: (this is also true for arguments to the
295: .Ic mode ,
296: .Ic set ,
297: .Ic toggle ,
298: .Ic unset ,
299: .Ic slc ,
300: .Ic environ ,
301: and
302: .Ic display
303: commands).
304: .Pp
305: .Bl -tag -width "mode type"
1.4 cgd 306: .It Ic auth Ar argument ...
307: The auth command manipulates the information sent through the
308: .Dv TELNET AUTHENTICATE
309: option. Valid arguments for the
310: auth command are as follows:
311: .Bl -tag -width "disable type"
312: .It Ic disable Ar type
313: Disables the specified type of authentication. To
314: obtain a list of available types, use the
315: .Ic auth disable \&?
316: command.
317: .It Ic enable Ar type
318: Enables the specified type of authentication. To
319: obtain a list of available types, use the
320: .Ic auth enable \&?
321: command.
322: .It Ic status
323: Lists the current status of the various types of
324: authentication.
325: .El
1.1 cgd 326: .It Ic close
327: Close a
328: .Tn TELNET
329: session and return to command mode.
330: .It Ic display Ar argument ...
331: Displays all, or some, of the
332: .Ic set
333: and
334: .Ic toggle
335: values (see below).
1.4 cgd 336: .It Ic encrypt Ar argument ...
337: The encrypt command manipulates the information sent through the
338: .Dv TELNET ENCRYPT
339: option.
340: .Pp
341: Note: Because of export controls, the
342: .Dv TELNET ENCRYPT
343: option is not supported outside of the United States and Canada.
344: .Pp
345: Valid arguments for the encrypt command are as follows:
346: .Bl -tag -width Ar
347: .It Ic disable Ar type Ic [input|output]
348: Disables the specified type of encryption. If you
349: omit the input and output, both input and output
350: are disabled. To obtain a list of available
351: types, use the
352: .Ic encrypt disable \&?
353: command.
354: .It Ic enable Ar type Ic [input|output]
355: Enables the specified type of encryption. If you
356: omit input and output, both input and output are
357: enabled. To obtain a list of available types, use the
358: .Ic encrypt enable \&?
359: command.
360: .It Ic input
361: This is the same as the
362: .Ic encrypt start input
363: command.
364: .It Ic -input
365: This is the same as the
366: .Ic encrypt stop input
367: command.
368: .It Ic output
369: This is the same as the
370: .Ic encrypt start output
371: command.
372: .It Ic -output
373: This is the same as the
374: .Ic encrypt stop output
375: command.
376: .It Ic start Ic [input|output]
377: Attempts to start encryption. If you omit
378: .Ic input
379: and
380: .Ic output,
381: both input and output are enabled. To
382: obtain a list of available types, use the
383: .Ic encrypt enable \&?
384: command.
385: .It Ic status
386: Lists the current status of encryption.
387: .It Ic stop Ic [input|output]
388: Stops encryption. If you omit input and output,
389: encryption is on both input and output.
390: .It Ic type Ar type
391: Sets the default type of encryption to be used
392: with later
393: .Ic encrypt start
394: or
395: .Ic encrypt stop
396: commands.
397: .El
398: .It Ic environ Ar arguments...
399: The
400: .Ic environ
401: command is used to manipulate the
1.6 ! lukem 402: variables that may be sent through the
1.4 cgd 403: .Dv TELNET ENVIRON
404: option.
405: The initial set of variables is taken from the users
406: environment, with only the
407: .Ev DISPLAY
408: and
409: .Ev PRINTER
410: variables being exported by default.
411: The
412: .Ev USER
413: variable is also exported if the
414: .Fl a
415: or
416: .Fl l
417: options are used.
418: .br
419: Valid arguments for the
420: .Ic environ
421: command are:
422: .Bl -tag -width Fl
423: .It Ic define Ar variable value
424: Define the variable
425: .Ar variable
426: to have a value of
427: .Ar value.
428: Any variables defined by this command are automatically exported.
429: The
430: .Ar value
431: may be enclosed in single or double quotes so
432: that tabs and spaces may be included.
433: .It Ic undefine Ar variable
434: Remove
435: .Ar variable
436: from the list of environment variables.
437: .It Ic export Ar variable
438: Mark the variable
439: .Ar variable
440: to be exported to the remote side.
441: .It Ic unexport Ar variable
442: Mark the variable
443: .Ar variable
444: to not be exported unless
445: explicitly asked for by the remote side.
446: .It Ic list
447: List the current set of environment variables.
448: Those marked with a
449: .Cm *
450: will be sent automatically,
451: other variables will only be sent if explicitly requested.
452: .It Ic \&?
453: Prints out help information for the
454: .Ic environ
455: command.
456: .El
457: .It Ic logout
458: Sends the
459: .Dv TELNET LOGOUT
460: option to the remote side.
461: This command is similar to a
462: .Ic close
463: command; however, if the remote side does not support the
464: .Dv LOGOUT
465: option, nothing happens.
466: If, however, the remote side does support the
467: .Dv LOGOUT
468: option, this command should cause the remote side to close the
469: .Tn TELNET
470: connection.
471: If the remote side also supports the concept of
472: suspending a user's session for later reattachment,
473: the logout argument indicates that you
474: should terminate the session immediately.
1.1 cgd 475: .It Ic mode Ar type
476: .Ar Type
477: is one of several options, depending on the state of the
478: .Tn TELNET
479: session.
480: The remote host is asked for permission to go into the requested mode.
481: If the remote host is capable of entering that mode, the requested
482: mode will be entered.
483: .Bl -tag -width Ar
484: .It Ic character
485: Disable the
486: .Dv TELNET LINEMODE
487: option, or, if the remote side does not understand the
488: .Dv LINEMODE
489: option, then enter \*(Lqcharacter at a time\*(Lq mode.
490: .It Ic line
491: Enable the
492: .Dv TELNET LINEMODE
493: option, or, if the remote side does not understand the
494: .Dv LINEMODE
495: option, then attempt to enter \*(Lqold-line-by-line\*(Lq mode.
496: .It Ic isig Pq Ic \-isig
497: Attempt to enable (disable) the
498: .Dv TRAPSIG
499: mode of the
500: .Dv LINEMODE
501: option.
502: This requires that the
503: .Dv LINEMODE
504: option be enabled.
505: .It Ic edit Pq Ic \-edit
506: Attempt to enable (disable) the
507: .Dv EDIT
508: mode of the
509: .Dv LINEMODE
510: option.
511: This requires that the
512: .Dv LINEMODE
513: option be enabled.
514: .It Ic softtabs Pq Ic \-softtabs
515: Attempt to enable (disable) the
516: .Dv SOFT_TAB
517: mode of the
518: .Dv LINEMODE
519: option.
520: This requires that the
521: .Dv LINEMODE
522: option be enabled.
523: .It Ic litecho Pq Ic \-litecho
524: Attempt to enable (disable) the
525: .Dv LIT_ECHO
526: mode of the
527: .Dv LINEMODE
528: option.
529: This requires that the
530: .Dv LINEMODE
531: option be enabled.
532: .It Ic \&?
533: Prints out help information for the
534: .Ic mode
535: command.
536: .El
537: .It Xo
538: .Ic open Ar host
539: .Oo Op Fl l
540: .Ar user
541: .Oc Ns Oo Fl
542: .Ar port Oc
543: .Xc
544: Open a connection to the named host.
545: If no port number
546: is specified,
547: .Nm telnet
548: will attempt to contact a
549: .Tn TELNET
550: server at the default port.
551: The host specification may be either a host name (see
552: .Xr hosts 5 )
553: or an Internet address specified in the \*(Lqdot notation\*(Rq (see
554: .Xr inet 3 ) .
555: The
556: .Op Fl l
557: option may be used to specify the user name
558: to be passed to the remote system via the
559: .Ev ENVIRON
560: option.
561: When connecting to a non-standard port,
562: .Nm telnet
563: omits any automatic initiation of
564: .Tn TELNET
1.4 cgd 565: options. When the port number is preceded by a minus sign,
1.3 jtc 566: the initial option negotiation is done.
1.1 cgd 567: After establishing a connection, the file
568: .Pa \&.telnetrc
569: in the
1.3 jtc 570: users home directory is opened. Lines beginning with a # are
1.1 cgd 571: comment lines. Blank lines are ignored. Lines that begin
1.4 cgd 572: without white space are the start of a machine entry. The
1.1 cgd 573: first thing on the line is the name of the machine that is
574: being connected to. The rest of the line, and successive
1.4 cgd 575: lines that begin with white space are assumed to be
1.1 cgd 576: .Nm telnet
577: commands and are processed as if they had been typed
578: in manually to the
579: .Nm telnet
580: command prompt.
581: .It Ic quit
582: Close any open
583: .Tn TELNET
584: session and exit
585: .Nm telnet .
586: An end of file (in command mode) will also close a session and exit.
587: .It Ic send Ar arguments
588: Sends one or more special character sequences to the remote host.
589: The following are the arguments which may be specified
590: (more than one argument may be specified at a time):
591: .Pp
592: .Bl -tag -width escape
593: .It Ic abort
594: Sends the
595: .Dv TELNET ABORT
596: (Abort
597: processes)
598: sequence.
599: .It Ic ao
600: Sends the
601: .Dv TELNET AO
602: (Abort Output) sequence, which should cause the remote system to flush
603: all output
604: .Em from
605: the remote system
606: .Em to
607: the user's terminal.
608: .It Ic ayt
609: Sends the
610: .Dv TELNET AYT
611: (Are You There)
612: sequence, to which the remote system may or may not choose to respond.
613: .It Ic brk
614: Sends the
615: .Dv TELNET BRK
616: (Break) sequence, which may have significance to the remote
617: system.
618: .It Ic ec
619: Sends the
620: .Dv TELNET EC
621: (Erase Character)
622: sequence, which should cause the remote system to erase the last character
623: entered.
624: .It Ic el
625: Sends the
626: .Dv TELNET EL
627: (Erase Line)
628: sequence, which should cause the remote system to erase the line currently
629: being entered.
630: .It Ic eof
631: Sends the
632: .Dv TELNET EOF
633: (End Of File)
634: sequence.
635: .It Ic eor
636: Sends the
637: .Dv TELNET EOR
638: (End of Record)
639: sequence.
640: .It Ic escape
641: Sends the current
642: .Nm telnet
643: escape character (initially \*(Lq^\*(Rq).
644: .It Ic ga
645: Sends the
646: .Dv TELNET GA
647: (Go Ahead)
648: sequence, which likely has no significance to the remote system.
649: .It Ic getstatus
650: If the remote side supports the
651: .Dv TELNET STATUS
652: command,
653: .Ic getstatus
654: will send the subnegotiation to request that the server send
655: its current option status.
656: .It Ic ip
657: Sends the
658: .Dv TELNET IP
659: (Interrupt Process) sequence, which should cause the remote
660: system to abort the currently running process.
661: .It Ic nop
662: Sends the
663: .Dv TELNET NOP
664: (No OPeration)
665: sequence.
666: .It Ic susp
667: Sends the
668: .Dv TELNET SUSP
669: (SUSPend process)
670: sequence.
671: .It Ic synch
672: Sends the
673: .Dv TELNET SYNCH
674: sequence.
675: This sequence causes the remote system to discard all previously typed
676: (but not yet read) input.
677: This sequence is sent as
678: .Tn TCP
679: urgent
680: data (and may not work if the remote system is a
681: .Bx 4.2
682: system -- if
683: it doesn't work, a lower case \*(Lqr\*(Rq may be echoed on the terminal).
1.4 cgd 684: .It Ic do Ar cmd
685: .It Ic dont Ar cmd
686: .It Ic will Ar cmd
687: .It Ic wont Ar cmd
688: Sends the
689: .Dv TELNET DO
690: .Ar cmd
691: sequence.
692: .Ar Cmd
693: can be either a decimal number between 0 and 255,
694: or a symbolic name for a specific
695: .Dv TELNET
696: command.
697: .Ar Cmd
698: can also be either
699: .Ic help
700: or
701: .Ic \&?
702: to print out help information, including
703: a list of known symbolic names.
1.1 cgd 704: .It Ic \&?
705: Prints out help information for the
706: .Ic send
707: command.
708: .El
709: .It Ic set Ar argument value
710: .It Ic unset Ar argument value
711: The
712: .Ic set
713: command will set any one of a number of
714: .Nm telnet
715: variables to a specific value or to
716: .Dv TRUE .
717: The special value
718: .Ic off
719: turns off the function associated with
720: the variable, this is equivalent to using the
721: .Ic unset
722: command.
723: The
724: .Ic unset
725: command will disable or set to
726: .Dv FALSE
727: any of the specified functions.
728: The values of variables may be interrogated with the
729: .Ic display
730: command.
731: The variables which may be set or unset, but not toggled, are
732: listed here. In addition, any of the variables for the
733: .Ic toggle
734: command may be explicitly set or unset using
735: the
736: .Ic set
737: and
738: .Ic unset
739: commands.
740: .Bl -tag -width escape
1.4 cgd 741: .It Ic ayt
742: If
743: .Tn TELNET
744: is in localchars mode, or
745: .Dv LINEMODE
746: is enabled, and the status character is typed, a
747: .Dv TELNET AYT
748: sequence (see
749: .Ic send ayt
750: preceding) is sent to the
751: remote host. The initial value for the "Are You There"
752: character is the terminal's status character.
1.1 cgd 753: .It Ic echo
754: This is the value (initially \*(Lq^E\*(Rq) which, when in
755: \*(Lqline by line\*(Rq mode, toggles between doing local echoing
756: of entered characters (for normal processing), and suppressing
757: echoing of entered characters (for entering, say, a password).
758: .It Ic eof
759: If
760: .Nm telnet
761: is operating in
762: .Dv LINEMODE
763: or \*(Lqold line by line\*(Rq mode, entering this character
764: as the first character on a line will cause this character to be
765: sent to the remote system.
766: The initial value of the eof character is taken to be the terminal's
767: .Ic eof
768: character.
769: .It Ic erase
770: If
771: .Nm telnet
772: is in
773: .Ic localchars
774: mode (see
775: .Ic toggle
776: .Ic localchars
777: below),
778: .Sy and
779: if
780: .Nm telnet
781: is operating in \*(Lqcharacter at a time\*(Rq mode, then when this
782: character is typed, a
783: .Dv TELNET EC
784: sequence (see
785: .Ic send
786: .Ic ec
787: above)
788: is sent to the remote system.
789: The initial value for the erase character is taken to be
790: the terminal's
791: .Ic erase
792: character.
793: .It Ic escape
794: This is the
795: .Nm telnet
796: escape character (initially \*(Lq^[\*(Rq) which causes entry
797: into
798: .Nm telnet
799: command mode (when connected to a remote system).
800: .It Ic flushoutput
801: If
802: .Nm telnet
803: is in
804: .Ic localchars
805: mode (see
806: .Ic toggle
807: .Ic localchars
808: below)
809: and the
810: .Ic flushoutput
811: character is typed, a
812: .Dv TELNET AO
813: sequence (see
814: .Ic send
815: .Ic ao
816: above)
817: is sent to the remote host.
818: The initial value for the flush character is taken to be
819: the terminal's
820: .Ic flush
821: character.
1.4 cgd 822: .It Ic forw1
823: .It Ic forw2
824: If
825: .Tn TELNET
826: is operating in
827: .Dv LINEMODE ,
828: these are the
829: characters that, when typed, cause partial lines to be
830: forwarded to the remote system. The initial value for
831: the forwarding characters are taken from the terminal's
832: eol and eol2 characters.
1.1 cgd 833: .It Ic interrupt
834: If
835: .Nm telnet
836: is in
837: .Ic localchars
838: mode (see
839: .Ic toggle
840: .Ic localchars
841: below)
842: and the
843: .Ic interrupt
844: character is typed, a
845: .Dv TELNET IP
846: sequence (see
847: .Ic send
848: .Ic ip
849: above)
850: is sent to the remote host.
851: The initial value for the interrupt character is taken to be
852: the terminal's
853: .Ic intr
854: character.
855: .It Ic kill
856: If
857: .Nm telnet
858: is in
859: .Ic localchars
860: mode (see
861: .Ic toggle
862: .Ic localchars
863: below),
864: .Ic and
865: if
866: .Nm telnet
867: is operating in \*(Lqcharacter at a time\*(Rq mode, then when this
868: character is typed, a
869: .Dv TELNET EL
870: sequence (see
871: .Ic send
872: .Ic el
873: above)
874: is sent to the remote system.
875: The initial value for the kill character is taken to be
876: the terminal's
877: .Ic kill
878: character.
879: .It Ic lnext
880: If
881: .Nm telnet
882: is operating in
883: .Dv LINEMODE
884: or \*(Lqold line by line\*(Lq mode, then this character is taken to
885: be the terminal's
886: .Ic lnext
887: character.
888: The initial value for the lnext character is taken to be
889: the terminal's
890: .Ic lnext
891: character.
892: .It Ic quit
893: If
894: .Nm telnet
895: is in
896: .Ic localchars
897: mode (see
898: .Ic toggle
899: .Ic localchars
900: below)
901: and the
902: .Ic quit
903: character is typed, a
904: .Dv TELNET BRK
905: sequence (see
906: .Ic send
907: .Ic brk
908: above)
909: is sent to the remote host.
910: The initial value for the quit character is taken to be
911: the terminal's
912: .Ic quit
913: character.
914: .It Ic reprint
915: If
916: .Nm telnet
917: is operating in
918: .Dv LINEMODE
919: or \*(Lqold line by line\*(Lq mode, then this character is taken to
920: be the terminal's
921: .Ic reprint
922: character.
923: The initial value for the reprint character is taken to be
924: the terminal's
925: .Ic reprint
926: character.
1.4 cgd 927: .It Ic rlogin
928: This is the rlogin escape character.
929: If set, the normal
930: .Tn TELNET
931: escape character is ignored unless it is
932: preceded by this character at the beginning of a line.
933: This character, at the beginning of a line followed by
934: a "." closes the connection; when followed by a ^Z it
935: suspends the telnet command. The initial state is to
936: disable the rlogin escape character.
1.1 cgd 937: .It Ic start
938: If the
939: .Dv TELNET TOGGLE-FLOW-CONTROL
940: option has been enabled,
941: then this character is taken to
942: be the terminal's
943: .Ic start
944: character.
945: The initial value for the kill character is taken to be
946: the terminal's
947: .Ic start
948: character.
949: .It Ic stop
950: If the
951: .Dv TELNET TOGGLE-FLOW-CONTROL
952: option has been enabled,
953: then this character is taken to
954: be the terminal's
955: .Ic stop
956: character.
957: The initial value for the kill character is taken to be
958: the terminal's
959: .Ic stop
960: character.
961: .It Ic susp
962: If
963: .Nm telnet
964: is in
965: .Ic localchars
966: mode, or
967: .Dv LINEMODE
968: is enabled, and the
969: .Ic suspend
970: character is typed, a
971: .Dv TELNET SUSP
972: sequence (see
973: .Ic send
974: .Ic susp
975: above)
976: is sent to the remote host.
977: The initial value for the suspend character is taken to be
978: the terminal's
979: .Ic suspend
980: character.
981: .It Ic tracefile
1.3 jtc 982: This is the file to which the output, caused by
1.1 cgd 983: .Ic netdata
984: or
985: .Ic option
986: tracing being
987: .Dv TRUE ,
988: will be written. If it is set to
989: .Dq Fl ,
990: then tracing information will be written to standard output (the default).
991: .It Ic worderase
992: If
993: .Nm telnet
994: is operating in
995: .Dv LINEMODE
996: or \*(Lqold line by line\*(Lq mode, then this character is taken to
997: be the terminal's
998: .Ic worderase
999: character.
1000: The initial value for the worderase character is taken to be
1001: the terminal's
1002: .Ic worderase
1003: character.
1004: .It Ic \&?
1005: Displays the legal
1006: .Ic set
1007: .Pq Ic unset
1008: commands.
1009: .El
1010: .It Ic slc Ar state
1011: The
1012: .Ic slc
1013: command (Set Local Characters) is used to set
1.6 ! lukem 1014: or change the state of the special
1.1 cgd 1015: characters when the
1016: .Dv TELNET LINEMODE
1017: option has
1018: been enabled. Special characters are characters that get
1019: mapped to
1020: .Tn TELNET
1021: commands sequences (like
1022: .Ic ip
1023: or
1024: .Ic quit )
1025: or line editing characters (like
1026: .Ic erase
1027: and
1028: .Ic kill ) .
1029: By default, the local special characters are exported.
1030: .Bl -tag -width Fl
1.4 cgd 1031: .It Ic check
1032: Verify the current settings for the current special characters.
1033: The remote side is requested to send all the current special
1034: character settings, and if there are any discrepancies with
1035: the local side, the local side will switch to the remote value.
1.1 cgd 1036: .It Ic export
1037: Switch to the local defaults for the special characters. The
1038: local default characters are those of the local terminal at
1039: the time when
1040: .Nm telnet
1041: was started.
1042: .It Ic import
1043: Switch to the remote defaults for the special characters.
1044: The remote default characters are those of the remote system
1045: at the time when the
1046: .Tn TELNET
1047: connection was established.
1048: .It Ic \&?
1049: Prints out help information for the
1050: .Ic slc
1051: command.
1052: .El
1.4 cgd 1053: .It Ic status
1054: Show the current status of
1055: .Nm telnet .
1056: This includes the peer one is connected to, as well
1057: as the current mode.
1.1 cgd 1058: .It Ic toggle Ar arguments ...
1059: Toggle (between
1060: .Dv TRUE
1061: and
1062: .Dv FALSE )
1063: various flags that control how
1064: .Nm telnet
1065: responds to events.
1066: These flags may be set explicitly to
1067: .Dv TRUE
1068: or
1069: .Dv FALSE
1070: using the
1071: .Ic set
1072: and
1073: .Ic unset
1074: commands listed above.
1075: More than one argument may be specified.
1076: The state of these flags may be interrogated with the
1077: .Ic display
1078: command.
1079: Valid arguments are:
1080: .Bl -tag -width Ar
1.4 cgd 1081: .It Ic authdebug
1082: Turns on debugging information for the authentication code.
1.1 cgd 1083: .It Ic autoflush
1084: If
1085: .Ic autoflush
1086: and
1087: .Ic localchars
1088: are both
1089: .Dv TRUE ,
1090: then when the
1091: .Ic ao ,
1092: or
1093: .Ic quit
1094: characters are recognized (and transformed into
1095: .Tn TELNET
1096: sequences; see
1097: .Ic set
1098: above for details),
1099: .Nm telnet
1100: refuses to display any data on the user's terminal
1101: until the remote system acknowledges (via a
1102: .Dv TELNET TIMING MARK
1103: option)
1104: that it has processed those
1105: .Tn TELNET
1106: sequences.
1107: The initial value for this toggle is
1108: .Dv TRUE
1109: if the terminal user had not
1110: done an "stty noflsh", otherwise
1111: .Dv FALSE
1112: (see
1113: .Xr stty 1 ) .
1.4 cgd 1114: .It Ic autodecrypt
1115: When the
1116: .Dv TELNET ENCRYPT
1117: option is negotiated, by
1118: default the actual encryption (decryption) of the data
1119: stream does not start automatically. The autoencrypt
1120: (autodecrypt) command states that encryption of the
1121: output (input) stream should be enabled as soon as
1122: possible.
1123: .Pp
1124: Note: Because of export controls, the
1125: .Dv TELNET ENCRYPT
1126: option is not supported outside the United States and Canada.
1127: .It Ic autologin
1128: If the remote side supports the
1129: .Dv TELNET AUTHENTICATION
1130: option
1131: .Tn TELNET
1132: attempts to use it to perform automatic authentication. If the
1133: .Dv AUTHENTICATION
1134: option is not supported, the user's login
1135: name are propagated through the
1136: .Dv TELNET ENVIRON
1137: option.
1138: This command is the same as specifying
1139: .Ar a
1140: option on the
1141: .Ic open
1142: command.
1.1 cgd 1143: .It Ic autosynch
1144: If
1145: .Ic autosynch
1146: and
1147: .Ic localchars
1148: are both
1149: .Dv TRUE ,
1150: then when either the
1151: .Ic intr
1152: or
1153: .Ic quit
1154: characters is typed (see
1155: .Ic set
1156: above for descriptions of the
1157: .Ic intr
1158: and
1159: .Ic quit
1160: characters), the resulting
1161: .Tn TELNET
1162: sequence sent is followed by the
1163: .Dv TELNET SYNCH
1164: sequence.
1165: This procedure
1166: .Ic should
1167: cause the remote system to begin throwing away all previously
1168: typed input until both of the
1169: .Tn TELNET
1170: sequences have been read and acted upon.
1171: The initial value of this toggle is
1172: .Dv FALSE .
1173: .It Ic binary
1174: Enable or disable the
1175: .Dv TELNET BINARY
1176: option on both input and output.
1177: .It Ic inbinary
1178: Enable or disable the
1179: .Dv TELNET BINARY
1180: option on input.
1181: .It Ic outbinary
1182: Enable or disable the
1183: .Dv TELNET BINARY
1184: option on output.
1185: .It Ic crlf
1186: If this is
1187: .Dv TRUE ,
1188: then carriage returns will be sent as
1189: .Li <CR><LF> .
1190: If this is
1191: .Dv FALSE ,
1192: then carriage returns will be send as
1193: .Li <CR><NUL> .
1194: The initial value for this toggle is
1195: .Dv FALSE .
1196: .It Ic crmod
1197: Toggle carriage return mode.
1198: When this mode is enabled, most carriage return characters received from
1199: the remote host will be mapped into a carriage return followed by
1200: a line feed.
1201: This mode does not affect those characters typed by the user, only
1202: those received from the remote host.
1203: This mode is not very useful unless the remote host
1204: only sends carriage return, but never line feed.
1205: The initial value for this toggle is
1206: .Dv FALSE .
1207: .It Ic debug
1208: Toggles socket level debugging (useful only to the
1209: .Ic super user ) .
1210: The initial value for this toggle is
1211: .Dv FALSE .
1.4 cgd 1212: .It Ic encdebug
1213: Turns on debugging information for the encryption code.
1.1 cgd 1214: .It Ic localchars
1215: If this is
1216: .Dv TRUE ,
1217: then the
1218: .Ic flush ,
1219: .Ic interrupt ,
1220: .Ic quit ,
1221: .Ic erase ,
1222: and
1223: .Ic kill
1224: characters (see
1225: .Ic set
1226: above) are recognized locally, and transformed into (hopefully) appropriate
1227: .Tn TELNET
1228: control sequences
1229: (respectively
1230: .Ic ao ,
1231: .Ic ip ,
1232: .Ic brk ,
1233: .Ic ec ,
1234: and
1235: .Ic el ;
1236: see
1237: .Ic send
1238: above).
1239: The initial value for this toggle is
1240: .Dv TRUE
1241: in \*(Lqold line by line\*(Rq mode,
1242: and
1243: .Dv FALSE
1244: in \*(Lqcharacter at a time\*(Rq mode.
1245: When the
1246: .Dv LINEMODE
1247: option is enabled, the value of
1248: .Ic localchars
1249: is ignored, and assumed to always be
1250: .Dv TRUE .
1251: If
1252: .Dv LINEMODE
1253: has ever been enabled, then
1254: .Ic quit
1255: is sent as
1256: .Ic abort ,
1257: and
1258: .Ic eof and
1259: .B suspend
1260: are sent as
1261: .Ic eof and
1262: .Ic susp ,
1263: see
1264: .Ic send
1265: above).
1266: .It Ic netdata
1267: Toggles the display of all network data (in hexadecimal format).
1268: The initial value for this toggle is
1269: .Dv FALSE .
1270: .It Ic options
1271: Toggles the display of some internal
1272: .Nm telnet
1273: protocol processing (having to do with
1274: .Tn TELNET
1275: options).
1276: The initial value for this toggle is
1277: .Dv FALSE .
1278: .It Ic prettydump
1279: When the
1280: .Ic netdata
1281: toggle is enabled, if
1282: .Ic prettydump
1283: is enabled the output from the
1284: .Ic netdata
1.3 jtc 1285: command will be formatted in a more user readable format.
1.1 cgd 1286: Spaces are put between each character in the output, and the
1.3 jtc 1287: beginning of any
1.1 cgd 1288: .Tn TELNET
1.4 cgd 1289: escape sequence is preceded by a '*' to aid in locating them.
1290: .It Ic skiprc
1291: When the skiprc toggle is
1292: .Dv TRUE ,
1293: .Tn TELNET
1294: skips the reading of the
1295: .Pa \&.telnetrc
1296: file in the users home
1297: directory when connections are opened. The initial
1298: value for this toggle is
1299: .Dv FALSE.
1300: .It Ic termdata
1301: Toggles the display of all terminal data (in hexadecimal format).
1302: The initial value for this toggle is
1303: .Dv FALSE .
1304: .It Ic verbose_encrypt
1305: When the
1306: .Ic verbose_encrypt
1307: toggle is
1308: .Dv TRUE ,
1309: .Tn TELNET
1310: prints out a message each time encryption is enabled or
1311: disabled. The initial value for this toggle is
1312: .Dv FALSE.
1313: Note: Because of export controls, data encryption
1314: is not supported outside of the United States and Canada.
1.1 cgd 1315: .It Ic \&?
1316: Displays the legal
1317: .Ic toggle
1318: commands.
1319: .El
1320: .It Ic z
1321: Suspend
1322: .Nm telnet .
1323: This command only works when the user is using the
1324: .Xr csh 1 .
1325: .It Ic \&! Op Ar command
1326: Execute a single command in a subshell on the local
1327: system. If
1328: .Ic command
1.3 jtc 1329: is omitted, then an interactive
1.1 cgd 1330: subshell is invoked.
1331: .It Ic \&? Op Ar command
1332: Get help. With no arguments,
1333: .Nm telnet
1334: prints a help summary.
1335: If a command is specified,
1336: .Nm telnet
1337: will print the help information for just that command.
1338: .El
1339: .Sh ENVIRONMENT
1340: .Nm Telnet
1341: uses at least the
1342: .Ev HOME ,
1343: .Ev SHELL ,
1344: .Ev DISPLAY ,
1345: and
1346: .Ev TERM
1.3 jtc 1347: environment variables.
1348: Other environment variables may be propagated
1.1 cgd 1349: to the other side via the
1350: .Dv TELNET ENVIRON
1351: option.
1352: .Sh FILES
1353: .Bl -tag -width ~/.telnetrc -compact
1354: .It Pa ~/.telnetrc
1355: user customized telnet startup values
1356: .El
1357: .Sh HISTORY
1358: The
1359: .Nm Telnet
1360: command appeared in
1361: .Bx 4.2 .
1362: .Sh NOTES
1363: .Pp
1364: On some remote systems, echo has to be turned off manually when in
1365: \*(Lqold line by line\*(Rq mode.
1366: .Pp
1367: In \*(Lqold line by line\*(Rq mode or
1368: .Dv LINEMODE
1369: the terminal's
1370: .Ic eof
1371: character is only recognized (and sent to the remote system)
1372: when it is the first character on a line.
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