1.\" Copyright (c) 1983, 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)telnet.1 6.14 (Berkeley) 03/14/91 7.\" 8.Vx 9.Vx 10.Dd 11.Dt TELNET 1 12.Os BSD 4.2 13.Sh NAME 14.Nm telnet 15.Nd user interface to the 16.Li TELNET 17protocol 18.Sh SYNOPSIS 19.Nm telnet 20.Op Fl d 21.Op Fl a 22.Op Fl n Ar tracefile 23.Op Fl e Ar escapechar 24.Ob 25.Op Fl l Ar user 26.Ar host 27.Op port 28.Oe 29.Sh DESCRIPTION 30The 31.Nm telnet 32command 33is used to communicate with another host using the 34.Li TELNET 35protocol. 36If 37.Nm telnet 38is invoked without the 39.Ar host 40argument, it enters command mode, 41indicated by its prompt 42.Pq Nm telnet\&> . 43In this mode, it accepts and executes the commands listed below. 44If it is invoked with arguments, it performs an 45.Ic open 46command with those arguments. 47.Pp 48Options: 49.Tw Fl 50.Tp Fl d 51Sets the initial value of the 52.Ic debug 53toggle to 54.Li TRUE 55.Tp Fl a 56Attempt automatic login. 57Currently, this sends the user name via the USER variable 58of the ENVIRON option if supported by the remote system. 59The name used is that of the current user as returned by 60.Xr getlogin 2 61if it agrees with the current user ID, 62otherwise it is the name associated with the user ID. 63.Tp Cx Fl n 64.Cx \&\ \& 65.Ar tracefile 66.Cx 67Opens 68.Ar tracefile 69for recording trace information. 70See the 71.Ic set tracefile 72command below. 73.Tp Cx Fl l 74.Cx \&\ \& 75.Ar user 76.Cx 77When connecting to the remote system, if the remote system 78understands the ENVIRON option, then 79.Ar user 80will be sent to the remote system as the value for the variable USER. 81This option implies the 82.Fl a 83option. 84This option may also be used with the 85.Ic open 86command. 87.Tp Cx Fl e 88.Cx \&\ \& 89.Ar escape char 90.Cx 91Sets the initial 92.Nm 93.B telnet 94escape character to 95.Ar escape char. 96If 97.Ar escape char 98is ommitted, then 99there will be no escape character. 100.Tp Ar host 101Indicates the official name, an alias, or the Internet address 102of a remote host. 103.Tp Ar port 104Indicates a port number (address of an application). If a number is 105not specified, the default 106.Nm telnet 107port is used. 108.Tp 109.Pp 110Once a connection has been opened, 111.Nm telnet 112will attempt to enable the 113.Li TELNET LINEMODE 114option. 115If this fails, then 116.Nm telnet 117will revert to one of two input modes: 118either \*(Lqcharacter at a time\*(Rq 119or \*(Lqold line by line\*(Rq 120depending on what the remote system supports. 121.Pp 122When 123.Li LINEMODE 124is enabled, character processing is done on the 125local system, under the control of the remote system. When input 126editing or character echoing is to be disabled, the remote system 127will relay that information. The remote system will also relay 128changes to any special characters that happen on the remote 129system, so that they can take effect on the local system. 130.Pp 131In \*(Lqcharacter at a time\*(Rq mode, most 132text typed is immediately sent to the remote host for processing. 133.Pp 134In \*(Lqold line by line\*(Rq mode, all text is echoed locally, 135and (normally) only completed lines are sent to the remote host. 136The \*(Lqlocal echo character\*(Rq (initially \*(Lq^E\*(Rq) may be used 137to turn off and on the local echo 138(this would mostly be used to enter passwords 139without the password being echoed). 140.Pp 141If the 142.Li LINEMODE 143option is enabled, or if the 144.Ic localchars 145toggle is TRUE (the default for \*(Lqold line by line\*(Lq; see below), 146the user's 147.Ic quit , 148.Ic intr , 149and 150.Ic flush 151characters are trapped locally, and sent as 152.Li TELNET 153protocol sequences to the remote side. 154If 155.Li LINEMODE 156has ever been enabled, then the user's 157.Ic susp 158and 159.Ic eof 160are also sent as 161.Li TELNET 162protocol sequences, 163and 164.Ic quit 165is sent as a 166.Li TELNET ABORT 167instead of 168.Li BREAK 169There are options (see 170.Ic toggle 171.Ic autoflush 172and 173.Ic toggle 174.Ic autosynch 175below) 176which cause this action to flush subsequent output to the terminal 177(until the remote host acknowledges the 178.Li TELNET 179sequence) and flush previous terminal input 180(in the case of 181.Ic quit 182and 183.Ic intr ) . 184.Pp 185While connected to a remote host, 186.Nm telnet 187command mode may be entered by typing the 188.Nm telnet 189\*(Lqescape character\*(Rq (initially \*(Lq^ 190\*(Rq). 191When in command mode, the normal terminal editing conventions are available. 192.Pp 193The following .Nm telnet 194commands are available. 195Only enough of each command to uniquely identify it need be typed 196(this is also true for arguments to the 197.Ic mode , 198.Ic set , 199.Ic toggle , 200.Ic unset , 201.Ic slc , 202.Ic environ , 203and 204.Ic display 205commands). 206.Pp 207.Tw Ic 208.Tp Ic close 209Close a 210.Li TELNET 211session and return to command mode. 212.Tp Cx Ic display 213.Cx \&\ \& 214.Ar argument ... 215.Cx 216Displays all, or some, of the 217.Ic set 218and 219.Ic toggle 220values (see below). 221.Tp Cx Ic mode 222.Cx \&\ \& 223.Ar type 224.Cx 225.Ar Type 226is one of several options, depending on the state of the 227.Li TELNET 228session. 229The remote host is asked for permission to go into the requested mode. 230If the remote host is capable of entering that mode, the requested 231mode will be entered. 232.Tw Ar 233.Tp Ic character 234Disable the 235.Li TELNET LINEMODE 236option, or, if the remote side does not understand the 237.Li LINEMODE 238option, then enter \*(Lqcharacter at a time\*(Lq mode. 239.Tp Ic line 240Enable the 241.Li TELNET LINEMODE 242option, or, if the remote side does not understand the 243.Li LINEMODE 244option, then attempt to enter \*(Lqold-line-by-line\*(Lq mode. 245.Tp Cx Ic isig 246.Cx \&\ \& 247.Pq Ic \-isig 248.Cx 249Attempt to enable (disable) the 250.Li TRAPSIG 251mode of the 252.Li LINEMODE 253option. 254This requires that the 255.Li LINEMODE 256option be enabled. 257.Tp Cx Ic edit 258.Cx \&\ \& 259.Pq Ic \-edit 260.Cx 261Attempt to enable (disable) the 262.Li EDIT 263mode of the 264.Li LINEMODE 265option. 266This requires that the 267.Li LINEMODE 268option be enabled. 269.Tp Cx Ic softtabs 270.Cx \&\ \& 271.Pq Ic \-softtabs 272.Cx 273Attempt to enable (disable) the 274.Li SOFT_TAB 275mode of the 276.Li LINEMODE 277option. 278This requires that the 279.Li LINEMODE 280option be enabled. 281.Tp Cx Ic litecho 282.Cx \&\ \& 283.Pq Ic \-litecho 284.Cx 285Attempt to enable (disable) the 286.Li LIT_ECHO 287mode of the 288.Li LINEMODE 289option. 290This requires that the 291.Li LINEMODE 292option be enabled. 293.Tp Ic \&? 294Prints out help information for the 295.Ic mode 296command. 297.Tp 298.Tp Cx Ic open 299.Cx \&\ \& 300.Ar host 301.Cx \&\ \& 302.Cx [ 303.Op Fl l 304.Cx \&\ \& 305.Ar user 306.Cx ] 307.Cx [ 308.Op Fl 309.Cx \&\ \& 310.Ar port 311.Cx ] 312.Cx 313Open a connection to the named host. 314If no port number 315is specified, 316.Nm telnet 317will attempt to contact a 318.Li TELNET 319server at the default port. 320The host specification may be either a host name (see 321.Xr hosts 5 ) 322or an Internet address specified in the \*(Lqdot notation\*(Rq (see 323.Xr inet 3 ) . 324The 325.Op Fl l 326option may be used to specify the user name 327to be passed to the remote system via the 328.Li ENVIRON 329option. 330When connecting to a non-standard port, 331.Nm telnet 332omits any automatic initiation of 333.Li TELNET 334options. When the port number is preceeded by a minus sign, 335the inital option negotiation is done. 336After establishing a connection, the file 337.Pa \&.telnetrc 338in the 339users home directory is opened. Lines begining with a # are 340comment lines. Blank lines are ignored. Lines that begin 341without whitespace are the start of a machine entry. The 342first thing on the line is the name of the machine that is 343being connected to. The rest of the line, and successive 344lines that begin with whitespace are assumed to be 345.Nm telnet 346commands and are processed as if they had been typed 347in manually to the 348.Nm telnet 349command prompt. 350.Tp Ic quit 351Close any open 352.Li TELNET 353session and exit 354.Nm telnet . 355An end of file (in command mode) will also close a session and exit. 356.Tp Cx Ic send 357.Cx \&\ \& 358.Ar arguments 359.Cx 360Sends one or more special character sequences to the remote host. 361The following are the arguments which may be specified 362(more than one argument may be specified at a time): 363.Pp 364.Tw Ds 365.Tp Ic abort 366Sends the 367.Li TELNET ABORT 368(ABORT processes) 369sequence. 370.Tp Ic ao 371Sends the 372.Li TELNET AO 373(Abort Output) sequence, which should cause the remote system to flush 374all output 375.Em from 376the remote system 377.Em to 378the user's terminal. 379.Tp Ic ayt 380Sends the 381.Li TELNET AYT 382(Are You There) 383sequence, to which the remote system may or may not choose to respond. 384.Tp Ic brk 385Sends the 386.Li TELNET BRK 387(Break) sequence, which may have significance to the remote 388system. 389.Tp Ic ec 390Sends the 391.Li TELNET EC 392(Erase Character) 393sequence, which should cause the remote system to erase the last character 394entered. 395.Tp Ic el 396Sends the 397.Li TELNET EL 398(Erase Line) 399sequence, which should cause the remote system to erase the line currently 400being entered. 401.Tp Ic eof 402Sends the 403.Li TELNET EOF 404(End Of File) 405sequence. 406.Tp Ic eor 407Sends the 408.Li TELNET EOR 409(End of Record) 410sequence. 411.Tp Ic escape 412Sends the current 413.Nm telnet 414escape character (initially \*(Lq^\*(Rq). 415.Tp Ic ga 416Sends the 417.Li TELNET GA 418(Go Ahead) 419sequence, which likely has no significance to the remote system. 420.Tp Ic getstatus 421If the remote side supports the 422.Li TELNET STATUS 423command, 424.Ic getstatus 425will send the subnegotiation to request that the server send 426its current option status. 427.Tp Ic ip 428Sends the 429.Li TELNET IP 430(Interrupt Process) sequence, which should cause the remote 431system to abort the currently running process. 432.Tp Ic nop 433Sends the 434.Li TELNET NOP 435(No OPeration) 436sequence. 437.Tp Ic susp 438Sends the 439.Li TELNET SUSP 440(SUSPend process) 441sequence. 442.Tp Ic synch 443Sends the 444.Li TELNET SYNCH 445sequence. 446This sequence causes the remote system to discard all previously typed 447(but not yet read) input. 448This sequence is sent as TCP urgent 449data (and may not work if the remote system is a 4.2 BSD system -- if 450it doesn't work, a lower case \*(Lqr\*(Rq may be echoed on the terminal). 451.Tp Ic \&? 452Prints out help information for the 453.Ic send 454command. 455.Tp 456.Tp Cx Ic set 457.Cx \&\ \& 458.Ar argument value 459.Cx 460.Tp Cx Ic unset 461.Cx \&\ \& 462.Ar argument value 463.Cx 464The 465.Ic set 466command will set any one of a number of 467.Nm telnet 468variables to a specific value or to TRUE. 469The special value 470.Ic off 471turns off the function associated with 472the variable, this is equivalent to using the 473.Ic unset 474command. 475The 476.Ic unset 477command will disable or set to FALSE any of the specified functions. 478The values of variables may be interrogated with the 479.Ic display 480command. 481The variables which may be set or unset, but not toggled, are 482listed here. In addition, any of the variables for the 483.Ic toggle 484command may be explicitly set or unset using 485the 486.Ic set 487and 488.Ic unset 489commands. 490.Tw Fl 491.Tp Ic echo 492This is the value (initially \*(Lq^E\*(Rq) which, when in 493\*(Lqline by line\*(Rq mode, toggles between doing local echoing 494of entered characters (for normal processing), and suppressing 495echoing of entered characters (for entering, say, a password). 496.Tp Ic eof 497If 498.Nm telnet 499is operating in 500.Li LINEMODE 501or \*(Lqold line by line\*(Rq mode, entering this character 502as the first character on a line will cause this character to be 503sent to the remote system. 504The initial value of the eof character is taken to be the terminal's 505.Ic eof 506character. 507.Tp Ic erase 508If 509.Nm telnet 510is in 511.Ic localchars 512mode (see 513.Ic toggle 514.Ic localchars 515below), 516.Sy and 517if 518.Nm telnet 519is operating in \*(Lqcharacter at a time\*(Rq mode, then when this 520character is typed, a 521.Li TELNET EC 522sequence (see 523.Ic send 524.Ic ec 525above) 526is sent to the remote system. 527The initial value for the erase character is taken to be 528the terminal's 529.Ic erase 530character. 531.Tp Ic escape 532This is the 533.Nm telnet 534escape character (initially \*(Lq^[\*(Rq) which causes entry 535into 536.Nm telnet 537command mode (when connected to a remote system). 538.Tp Ic flushoutput 539If 540.Nm telnet 541is in 542.Ic localchars 543mode (see 544.Ic toggle 545.Ic localchars 546below) 547and the 548.Ic flushoutput 549character is typed, a 550.Li TELNET AO 551sequence (see 552.Ic send 553.Ic ao 554above) 555is sent to the remote host. 556The initial value for the flush character is taken to be 557the terminal's 558.Ic flush 559character. 560.Tp Ic interrupt 561If 562.Nm telnet 563is in 564.Ic localchars 565mode (see 566.Ic toggle 567.Ic localchars 568below) 569and the 570.Ic interrupt 571character is typed, a 572.Li TELNET IP 573sequence (see 574.Ic send 575.Ic ip 576above) 577is sent to the remote host. 578The initial value for the interrupt character is taken to be 579the terminal's 580.Ic intr 581character. 582.Tp Ic kill 583If 584.Nm telnet 585is in 586.Ic localchars 587mode (see 588.Ic toggle 589.Ic localchars 590below), 591.Ic and 592if 593.Nm telnet 594is operating in \*(Lqcharacter at a time\*(Rq mode, then when this 595character is typed, a 596.Li TELNET EL 597sequence (see 598.Ic send 599.Ic el 600above) 601is sent to the remote system. 602The initial value for the kill character is taken to be 603the terminal's 604.Ic kill 605character. 606.Tp Ic lnext 607If 608.Nm telnet 609is operating in 610.Li LINEMODE 611or \*(Lqold line by line\*(Lq mode, then this character is taken to 612be the terminal's 613.Ic lnext 614character. 615The initial value for the lnext character is taken to be 616the terminal's 617.Ic lnext 618character. 619.Tp Ic quit 620If 621.Nm telnet 622is in 623.Ic localchars 624mode (see 625.Ic toggle 626.Ic localchars 627below) 628and the 629.Ic quit 630character is typed, a 631.Li TELNET BRK 632sequence (see 633.Ic send 634.Ic brk 635above) 636is sent to the remote host. 637The initial value for the quit character is taken to be 638the terminal's 639.Ic quit 640character. 641.Tp Ic reprint 642If 643.Nm telnet 644is operating in 645.Li LINEMODE 646or \*(Lqold line by line\*(Lq mode, then this character is taken to 647be the terminal's 648.Ic reprint 649character. 650The initial value for the reprint character is taken to be 651the terminal's 652.Ic reprint 653character. 654.Tp Ic start 655If the 656.Li TELNET TOGGLE-FLOW-CONTROL 657option has been enabled, 658then this character is taken to 659be the terminal's 660.Ic start 661character. 662The initial value for the kill character is taken to be 663the terminal's 664.Ic start 665character. 666.Tp Ic stop 667If the 668.Li TELNET TOGGLE-FLOW-CONTROL 669option has been enabled, 670then this character is taken to 671be the terminal's 672.Ic stop 673character. 674The initial value for the kill character is taken to be 675the terminal's 676.Ic stop 677character. 678.Tp Ic susp 679If 680.Nm telnet 681is in 682.Ic localchars 683mode, or 684.Li LINEMODE 685is enabled, and the 686.Ic suspend 687character is typed, a 688.Li TELNET SUSP 689sequence (see 690.Ic send 691.Ic susp 692above) 693is sent to the remote host. 694The initial value for the suspend character is taken to be 695the terminal's 696.Ic suspend 697character. 698.Tp Ic tracefile 699Thi is the file to which the output, caused by 700.Ic netdata 701or 702.Ic option 703tracing being TRUE, will be written. If it is set to 704.Dq Fl , 705then tracing information will be written to standard output (the default). 706.Tp Ic worderase 707If 708.Nm telnet 709is operating in 710.Li LINEMODE 711or \*(Lqold line by line\*(Lq mode, then this character is taken to 712be the terminal's 713.Ic worderase 714character. 715The initial value for the worderase character is taken to be 716the terminal's 717.Ic worderase 718character. 719.Tp Ic \&? 720Displays the legal 721.Ic set 722.Pq Ic unset 723commands. 724.Tp 725.Tp Cx Ic slc 726.Cx \&\ \& 727.Ar state 728.Cx 729The 730.Ic slc 731command (Set Local Characters) is used to set 732or change the state of the the special 733characters when the 734.Li TELNET LINEMODE 735option has 736been enabled. Special characters are characters that get 737mapped to 738.Li TELNET 739commands sequences (like 740.Ic ip 741or 742.Ic quit ) 743or line editing characters (like 744.Ic erase 745and 746.Ic kill ) . 747By default, the local special characters are exported. 748.Tw Fl 749.Tp Ic export 750Switch to the local defaults for the special characters. The 751local default characters are those of the local terminal at 752the time when 753.Nm telnet 754was started. 755.Tp Ic import 756Switch to the remote defaults for the special characters. 757The remote default characters are those of the remote system 758at the time when the 759.Li TELNET 760connection was established. 761.Tp Ic check 762Verify the current settings for the current special characters. 763The remote side is requested to send all the current special 764character settings, and if there are any discrepencies with 765the local side, the local side will switch to the remote value. 766.Tp Ic \&? 767Prints out help information for the 768.Ic slc 769command. 770.Tp 771.Tp Cx Ic environ 772.Cx \&\ \& 773.Ar arguments... 774.Cx 775The 776.Ic environ 777command is used to manipulate the 778the variables that my be sent through the 779.Li TELNET ENVIRON 780option. 781The initial set of variables is taken from the users 782environment, with only the 783.Ev DISPLAY 784and 785.Ev PRINTER 786variables being exported by default. 787The 788.Ev USER 789variable is also exported if the 790.Fl a 791or 792.Fl l 793options are used. 794.br 795Valid arguments for the \fBenviron\fP command are: 796.Tw Fl 797.Tp Cx Ic define 798.Cx \&\ \& 799.Ar variable value 800.Cx 801Define the variable 802.Ar variable 803to have a value of 804.Ar value. 805Any variables defined by this command are automatically exported. 806The 807.Ar value 808may be enclosed in single or double quotes so 809that tabs and spaces may be included. 810.Tp Cx Ic undefine 811.Cx \&\ \& 812.Ar variable 813.Cx 814Remove 815.Ar variable 816from the list of environment variables. 817.Tp Cx Ic export 818.Cx \&\ \& 819.Ar variable 820.Cx 821Mark the variable 822.Ar variable 823to be exported to the remote side. 824.Tp Cx Ic unexport 825.Cx \&\ \& 826.Ar variable 827.Cx 828Mark the variable 829.Ar variable 830to not be exported unless 831explicitly asked for by the remote side. 832.Tp Ic list 833List the current set of environment variables. 834Those marked with a \fB*\fR will be sent automatically, 835other variables will only be sent if explicitly requested. 836.Tp Ic \&? 837Prints out help information for the 838.Ic environ 839command. 840.Tp 841.Tp Cx Ic toggle 842.Cx \&\ \& 843.Ar arguments ... 844.Cx 845Toggle (between 846TRUE 847and 848FALSE) 849various flags that control how 850.Nm telnet 851responds to events. 852These flags may be set explicitly to TRUE or FALSE 853using the 854.Ic set 855and 856.Ic unset 857commands listed above. 858More than one argument may be specified. 859The state of these flags may be interrogated with the 860.Ic display 861command. 862Valid arguments are: 863.Tw Ar 864.Tp Ic autoflush 865If 866.Ic autoflush 867and 868.Ic localchars 869are both 870TRUE, 871then when the 872.Ic ao , 873or 874.Ic quit 875characters are recognized (and transformed into 876.Li TELNET 877sequences; see 878.Ic set 879above for details), 880.Nm telnet 881refuses to display any data on the user's terminal 882until the remote system acknowledges (via a 883.Li TELNET TIMING MARK 884option) 885that it has processed those 886.Li TELNET 887sequences. 888The initial value for this toggle is TRUE if the terminal user had not 889done an "stty noflsh", otherwise FALSE (see 890.Xr stty 1 ) . 891.Tp Ic autosynch 892If 893.Ic autosynch 894and 895.Ic localchars 896are both 897TRUE, 898then when either the 899.Ic intr 900or 901.Ic quit 902characters is typed (see 903.Ic set 904above for descriptions of the 905.Ic intr 906and 907.Ic quit 908characters), the resulting 909.Li TELNET 910sequence sent is followed by the 911.Li TELNET SYNCH 912sequence. 913This procedure 914.Ic should 915cause the remote system to begin throwing away all previously 916typed input until both of the 917.Li TELNET 918sequences have been read and acted upon. 919The initial value of this toggle is FALSE. 920.Tp Ic binary 921Enable or disable the 922.Li TELNET BINARY 923option on both input and output. 924.Tp Ic inbinary 925Enable or disable the 926.Li TELNET BINARY 927option on input. 928.Tp Ic outbinary 929Enable or disable the 930.Li TELNET BINARY 931option on output. 932.Tp Ic crlf 933If this is TRUE, then carriage returns will be sent as <CR><LF>. 934If this is FALSE, then carriage returns will be send as <CR><NUL>. 935The initial value for this toggle is FALSE. 936.Tp Ic crmod 937Toggle carriage return mode. 938When this mode is enabled, most carriage return characters received from 939the remote host will be mapped into a carriage return followed by 940a line feed. 941This mode does not affect those characters typed by the user, only 942those received from the remote host. 943This mode is not very useful unless the remote host 944only sends carriage return, but never line feed. 945The initial value for this toggle is FALSE. 946.Tp Ic debug 947Toggles socket level debugging (useful only to the 948.Ic super user ) . 949The initial value for this toggle is FALSE. 950.Tp Ic localchars 951If this is 952TRUE, 953then the 954.Ic flush , 955.Ic interrupt , 956.Ic quit , 957.Ic erase , 958and 959.Ic kill 960characters (see 961.Ic set 962above) are recognized locally, and transformed into (hopefully) appropriate 963.Li TELNET 964control sequences 965(respectively 966.Ic ao , 967.Ic ip , 968.Ic brk , 969.Ic ec , 970and 971.Ic el ; 972see 973.Ic send 974above). 975The initial value for this toggle is TRUE in \*(Lqold line by line\*(Rq mode, 976and FALSE in \*(Lqcharacter at a time\*(Rq mode. 977When the 978.Li LINEMODE 979option is enabled, the value of 980.Ic localchars 981is ignored, and assumed to always be TRUE. 982If 983.Li LINEMODE 984has ever been enabled, then 985.Ic quit 986is sent as 987.Ic abort , 988and 989.Ic eof and 990.B suspend 991are sent as 992.Ic eof and 993.Ic susp , 994see 995.Ic send 996above). 997.Tp Ic netdata 998Toggles the display of all network data (in hexadecimal format). 999The initial value for this toggle is FALSE. 1000.Tp Ic options 1001Toggles the display of some internal 1002.Nm telnet 1003protocol processing (having to do with 1004.Li TELNET 1005options). 1006The initial value for this toggle is FALSE. 1007.Tp Ic prettydump 1008When the 1009.Ic netdata 1010toggle is enabled, if 1011.Ic prettydump 1012is enabled the output from the 1013.Ic netdata 1014command will be formated in a more user readable format. 1015Spaces are put between each character in the output, and the 1016begining of any 1017.Li TELNET 1018escape sequence is preceeded by a '*' to aid in locating them. 1019.Tp Ic \&? 1020Displays the legal 1021.Ic toggle 1022commands. 1023.Tp 1024.Tp Ic z 1025Suspend 1026.Nm telnet . 1027This command only works when the user is using the 1028.Xr csh 1 . 1029.Tp Cx Ic \&! 1030.Cx \&\ \& 1031.Op Ar command 1032.Cx 1033Execute a single command in a subshell on the local 1034system. If 1035.Ic command 1036is ommitted, then an interactive 1037subshell is invoked. 1038.Tp Ic status 1039Show the current status of 1040.Nm telnet . 1041This includes the peer one is connected to, as well 1042as the current mode. 1043.Tp Cx Ic \&? 1044.Cx \&\ \& 1045.Op Ar command 1046.Cx 1047Get help. With no arguments, 1048.Nm telnet 1049prints a help summary. 1050If a command is specified, 1051.Nm telnet 1052will print the help information for just that command. 1053.Sh ENVIRONMENT 1054.Nm Telnet 1055uses at least the 1056.Ev HOME , 1057.Ev SHELL , 1058.Ev DISPLAY , 1059and 1060.Ev TERM 1061environent variables. 1062Other envirnoment variables may be propogated 1063to the other side via the 1064.Li TELNET ENVIRON 1065option. 1066.Sh FILES 1067.Dw ~/.telnetrc 1068.Di L 1069.Dp Pa ~/.telnetrc 1070user customized telnet startup values 1071.Dp 1072.Sh HISTORY 1073.Nm Telnet 1074appeared in 4.2 BSD. 1075.Sh NOTES 1076.Pp 1077On some remote systems, echo has to be turned off manually when in 1078\*(Lqold line by line\*(Rq mode. 1079.Pp 1080In \*(Lqold line by line\*(Rq mode or 1081.Li LINEMODE 1082the terminal's 1083.Ic eof 1084character is only recognized (and sent to the remote system) 1085when it is the first character on a line. 1086