1.\" Copyright (c) 1985, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)termcap.5 8.1 (Berkeley) 06/08/93 7.\" 8.Dd 9.Dt TERMCAP 5 10.Os BSD 3 11.Sh NAME 12.Nm termcap 13.Nd terminal capability data base 14.Sh SYNOPSIS 15.Nm termcap 16.Sh DESCRIPTION 17The 18.Nm Termcap 19file 20is a data base describing terminals, 21used, 22for example, 23by 24.Xr \&vi 1 25and 26.Xr curses 3 . 27Terminals are described in 28.Nm termcap 29by giving a set of capabilities that they have and by describing 30how operations are performed. 31Padding requirements and initialization sequences 32are included in 33.Nm termcap . 34.Pp 35Entries in 36.Nm termcap 37consist of a number of `:'-separated fields. 38The first entry for each terminal gives the names that are known for the 39terminal, separated by `|' characters. 40The first name given is the most common abbreviation for the terminal. 41The last name given should be a long name fully identifying the terminal, 42and all others are understood as synonyms for the terminal name. 43All names but the last should be in lower case and contain no blanks; 44the last name may well contain upper case characters and blanks for 45readability. 46.Pp 47Terminal names (except for the last, verbose entry) 48should be chosen using the following conventions. 49The particular piece of hardware making up the terminal 50should have a root name chosen, thus 51.Dq hp2621 52This name should not contain hyphens. 53Modes that the hardware can be in 54or user preferences 55should be indicated by appending a hyphen and an indicator of the mode. 56Therefore, a 57.Dq vt100 58in 132-column mode would be 59.Dq vt100-w . 60The following suffixes should be used where possible: 61.Pp 62.Bd -filled -offset indent 63.Bl -column indent "With automatic margins (usually default)xx" 64.Sy Suffix Meaning Example 65-w Wide mode (more than 80 columns) vt100-w 66-am With automatic margins (usually default) vt100-am 67-nam Without automatic margins vt100-nam 68.Pf \- Ar n Ta No "Number of lines on the screen aaa-60" 69-na No arrow keys (leave them in local) concept100-na 70.Pf \- Ar \&np Ta No "Number of pages of memory concept100-4p" 71-rv Reverse video concept100-rv 72.El 73.Ed 74.Sh CAPABILITIES 75The characters in the 76The 77.Em Notes 78function 79field in the table have the following meanings 80(more than one may apply to a capability): 81.Pp 82.Bd -unfilled -offset indent 83N indicates numeric parameter(s) 84P indicates that padding may be specified 85* indicates that padding may be based on the number of lines affected 86o indicates capability is obsolete 87.Ed 88.Pp 89.Dq Obsolete 90capabilities have no 91.Em terminfo 92equivalents, 93since they were considered useless, 94or are subsumed by other capabilities. 95New software should not rely on them at all. 96.Pp 97.Bl -column indent indent indent 98.Sy Name Type Notes Description 99functions 100.It "ae str (P) End alternate character set." 101.It AL str (NP*) Add" 102.Em n 103new blank lines 104.It "al str (P*) Add new blank line." 105.It "am bool Terminal has automatic margins." 106.It "as str (P) Start alternate character set." 107.It "bc str (o) Backspace if not." 108.Sy \&^H . 109.It "bl str (P) Audible signal (bell)." 110.It "bs bool (o) Terminal can backspace with" 111.Sy \&^H . 112.It "bt str (P) Back tab." 113.It "bw bool " Ta Sy \&le 114(backspace) wraps from column 0 to last column. 115.It "CC str Terminal settable command character in prototype." 116.It "cd str (P*) Clear to end of display." 117.It "ce str (P) Clear to end of line." 118.It "ch str (NP) Set cursor column (horizontal position)." 119.It "cl str (P*) Clear screen and home cursor." 120.It "CM str (NP) Memory-relative cursor addressing." 121.It "cm str (NP) Screen-relative cursor motion." 122.It "co num Number of columns in a line (See" 123.Sx BUGS 124section below). 125.It "cr str (P) Carriage return." 126.It "cs str (NP) Change scrolling region (VT100)." 127.It "ct str (P) Clear all tab stops." 128.It "cv str (NP) Set cursor row (vertical position)." 129.It "da bool Display may be retained above the screen." 130.It "dB num (o) Milliseconds of" 131.Sy \&bs 132delay needed (default 0). 133.It "db bool Display may be retained below the screen." 134.It "DC str (NP*) Delete" 135.Em n 136characters. 137.It "dC num (o) Milliseconds of" 138.Sy \&cr 139delay needed (default 0). 140.It "dc str (P*) Delete character." 141.It "dF num (o) Milliseconds of" 142.Sy \&ff 143delay needed (default 0). 144.It "DL str (NP*) Delete" 145.Ar n 146lines. 147.It "dl str (P*) Delete line." 148.It "dm str Enter delete mode." 149.It "dN num (o) Milliseconds of 150.Sy \&nl 151delay needed (default 0). 152.It "DO str (NP*) Move cursor down: 153.Ar n 154lines. 155.It "do str Down one line." 156.It "ds str Disable status line." 157.It "dT num (o) Milliseconds of horizontal tab delay needed (default 0)." 158.It "dV num (o) Milliseconds of vertical tab delay needed (default 0)." 159.It "ec str (NP) Erase" 160.Ar n 161characters. 162.It "ed str End delete mode." 163.It "ei str End insert mode." 164.It "eo bool Can erase overstrikes with a blank." 165.It "EP bool (o) Even parity." 166.It "es bool Escape can be used on the status line." 167.It "ff str (P*) Hardcopy terminal page eject." 168.It "fs str Return from status line." 169.It "gn bool Generic line type, for example dialup, switch)." 170.It "hc bool Hardcopy terminal." 171.It "HD bool (o) Half-duplex." 172.It "hd str Half-line down (forward 1/2 linefeed)." 173.It "ho str (P) Home cursor." 174.It "hs bool Has extra" 175.Dq status line . 176.It "hu str Half-line up (reverse 1/2 linefeed)." 177.It "hz bool Cannot print ``~'' (Hazeltine)." 178.It "i1-i3 str Terminal initialization strings" 179.Pf ( Xr terminfo 180only) 181.It "IC str (NP*) Insert" 182.Ar n 183blank characters. 184.It "ic str (P*) Insert character." 185.It "if str Name of file containing initialization string." 186.It "im str Enter insert mode." 187.It "in bool Insert mode distinguishes nulls." 188.It "iP str Pathname of program for initialization" 189.Pf ( Xr terminfo 190only). 191.It "ip str (P*) Insert pad after character inserted." 192.It "is str Terminal initialization string" 193.Pf ( Nm termcap 194only). 195.It "it num Tabs initially every" 196.Ar n 197positions. 198.It "K1 str Sent by keypad upper left." 199.It "K2 str Sent by keypad upper right." 200.It "K3 str Sent by keypad center." 201.It "K4 str Sent by keypad lower left." 202.It "K5 str Sent by keypad lower right." 203.It "k0-k9 str Sent by function keys 0-9." 204.It "kA str Sent by insert-line key." 205.It "ka str Sent by clear-all-tabs key." 206.It "kb str Sent by backspace key." 207.It "kC str Sent by clear-screen or erase key." 208.It "kD str Sent by delete-character key." 209.It "kd str Sent by down-arrow key." 210.It "kE str Sent by clear-to-end-of-line key." 211.It "ke str Out of" 212.Dq keypad transmit 213mode. 214.It "kF str Sent by scroll-forward/down key." 215.It "kH str Sent by home-down key." 216.It "kh str Sent by home key." 217.It "kI str Sent by insert-character or enter-insert-mode key." 218.It "kL str Sent by delete-line key." 219.It "kl str Sent by left-arrow key." 220.It "kM str Sent by insert key while in insert mode." 221.It "km bool Has a" 222.Dq meta 223key (shift, sets parity bit). 224.It "kN str Sent by next-page key." 225.It "kn num (o) Number of function" 226.Pq Sy \&k\&0 Ns \- Sy \&k\&9 227keys (default 0). 228.It "ko str (o) Termcap entries for other non-function keys." 229.It "kP str Sent by previous-page key." 230.It "kR str Sent by scroll-backward/up key." 231.It "kr str Sent by right-arrow key." 232.It "kS str Sent by clear-to-end-of-screen key." 233.It "ks str Put terminal in" 234.Dq keypad transmit 235mode. 236.It "kT str Sent by set-tab key." 237.It "kt str Sent by clear-tab key." 238.It "ku str Sent by up-arrow key." 239.It "l0-l9 str Labels on function keys if not" 240.Dq \&f Ns Em n . 241.It "LC bool (o) Lower-case only." 242.It "LE str (NP) Move cursor left" 243.Ar n 244positions. 245.It "le str (P) Move cursor left one position." 246.It "li num Number of lines on screen or page (See" 247.Sx BUGS 248section below) 249.It "ll str Last line, first column 250.It "lm num Lines of memory if >" Sy \&li 251(0 means varies). 252.It "ma str (o) Arrow key map (used by" 253.Xr \&vi 254version 2 only). 255.It "mb str Turn on blinking attribute." 256.It "md str Turn on bold (extra bright) attribute." 257.It "me str Turn off all attributes." 258.It "mh str Turn on half-bright attribute." 259.It "mi bool Safe to move while in insert mode." 260.It "mk str Turn on blank attribute (characters invisible)." 261.It "ml str (o) Memory lock on above cursor." 262.It "mm str Turn on" 263.Dq meta mode 264(8th bit). 265.It "mo str Turn off" 266.Dq meta mode . 267.It "mp str Turn on protected attribute." 268.It "mr str Turn on reverse-video attibute." 269.It "ms bool Safe to move in standout modes." 270.It "mu str (o) Memory unlock (turn off memory lock)." 271.It "nc bool (o) No correctly-working" 272.Sy \&cr 273(Datamedia 2500, Hazeltine 2000). 274.It "nd str Non-destructive space (cursor right)." 275.It "NL bool (o)" Ta Sy \&\en No "is newline, not line feed." 276.It "nl str (o) Newline character if not" Sy \en . 277.It "ns bool (o) Terminal is a" Tn CRT No "but doesn't scroll." 278.It "nw str (P) Newline (behaves like" 279.Sy \&cr 280followed by 281.Sy \&do ). 282.It "OP bool (o) Odd parity." 283.It "os bool Terminal overstrikes." 284.It "pb num Lowest baud where delays are required." 285.It "pc str Pad character (default" Tn NUL ). 286.It "pf str Turn off the printer." 287.It "pk str Program function key" 288.Em n 289to type string 290.Em s 291.Pf ( Xr terminfo 292only). 293.It "pl str Program function key" 294.Em n 295to execute string 296.Em s 297.Pf ( Xr terminfo 298only). 299.It "pO str (N) Turn on the printer for" 300.Em n 301bytes. 302.It "po str Turn on the printer." 303.It "ps str Print contents of the screen." 304.It "pt bool (o) Has hardware tabs (may need to be set with" 305.Sy \&is ). 306.It "px str Program function key" 307.Em n 308to transmit string 309.Em s 310.Pf ( Xr terminfo 311only). 312.It "r1-r3 str Reset terminal completely to sane modes" 313.Pf ( Xr terminfo 314only). 315.It "rc str (P) Restore cursor to position of last" 316.Sy \&sc . 317.It "rf str Name of file containing reset codes." 318.It "RI str (NP) Move cursor right" 319.Em n 320positions. 321.It "rp str (NP*) Repeat character" 322.Em c n 323times. 324.It "rs str Reset terminal completely to sane modes" 325.Pf ( Nm termcap 326only). 327.It "sa str (NP) Define the video attributes." 328.It "sc str (P) Save cursor position." 329.It "se str End standout mode." 330.It "SF str (NP*) Scroll forward" 331.Em n 332lines. 333.It "sf str (P) Scroll text up." 334.It "sg num Number of garbage chars left by" 335.Sy \&so 336or 337.Sy \&se 338(default 0). 339.It "so str Begin standout mode." 340.It "SR str (NP*) Scroll backward" 341.Em n 342lines. 343.It "sr str (P) Scroll text down." 344.It "st str Set a tab in all rows, current column." 345.It "ta str (P) Tab to next 8-position hardware tab stop." 346.It "tc str Entry of similar terminal \- must be last." 347.It "te str String to end programs that use" 348.Nm termcap . 349.It "ti str String to begin programs that use" 350.Nm termcap . 351.It "ts str (N) Go to status line, column" 352.Em n . 353.It "UC bool (o) Upper-case only." 354.It "uc str Underscore one character and move past it." 355.It "ue str End underscore mode." 356.It "ug num Number of garbage chars left by" 357.Sy \&us 358or 359.Sy \&ue 360(default 0). 361.It "ul bool Underline character overstrikes." 362.It "UP str (NP*) Move cursor up" 363.Em n 364lines. 365.It "up str Upline (cursor up)." 366.It "us str Start underscore mode." 367.It "vb str Visible bell (must not move cursor)." 368.It "ve str Make cursor appear normal (undo" 369.Sy \&vs Ns / Sy \&vi ) . 370.It "vi str Make cursor invisible." 371.It "vs str Make cursor very visible." 372.It "vt num Virtual terminal number (not supported on all systems)." 373.It "wi str (N) Set current window." 374.It "ws num Number of columns in status line." 375.It "xb bool Beehive" 376.Pf ( "f1=" Dv ESC , 377.Pf "f2=" Sy \&^C ) . 378.It "xn bool Newline ignored after 80 cols (Concept)." 379.It "xo bool Terminal uses xoff/xon" 380.Pq Dv DC3 Ns / Ns Dv DC1 381handshaking. 382.It "xr bool (o) Return acts like" 383.Sy "ce cr nl" 384(Delta Data). 385.It "xs bool Standout not erased by overwriting (Hewlett-Packard)." 386.It "xt bool Tabs ruin, magic" 387.SY \&so 388char (Teleray 1061). 389.It "xx bool (o) Tektronix 4025 insert-line." 390.El 391.Ss A Sample Entry 392The following entry, which describes the Concept\-100, is among the more 393complex entries in the 394.Nm termcap 395file as of this writing. 396.Pp 397.Bd -literal 398ca\||\|concept100\||\|c100\||\|concept\||\|c104\||\|concept100-4p\||\|HDS Concept\-100:\e 399 :al=3*\eE^R:am:bl=^G:cd=16*\eE^C:ce=16\eE^U:cl=2*^L:cm=\eEa%+ %+ :\e 400 :co#80:.cr=9^M:db:dc=16\eE^A:dl=3*\eE^B:do=^J:ei=\eE\e200:eo:im=\eE^P:in:\e 401 :ip=16*:is=\eEU\eEf\eE7\eE5\eE8\eEl\eENH\eEK\eE\e200\eEo&\e200\eEo\e47\eE:k1=\eE5:\e 402 :k2=\eE6:k3=\eE7:kb=^h:kd=\eE<:ke=\eEx:kh=\eE?:kl=\eE>:kr=\eE=:ks=\eEX:\e 403 :ku=\eE;:le=^H:li#24:mb=\eEC:me=\eEN\e200:mh=\eEE:mi:mk=\eEH:mp=\eEI:\e 404 :mr=\eED:nd=\eE=:pb#9600:rp=0.2*\eEr%.%+ :se=\eEd\eEe:sf=^J:so=\eEE\eED:\e 405 :.ta=8\et:te=\eEv \e200\e200\e200\e200\e200\e200\eEp\er\en:\e 406 :ti=\eEU\eEv 8p\eEp\er:ue=\eEg:ul:up=\eE;:us=\eEG:\e 407 :vb=\eEk\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\eEK:\e 408 :ve=\eEw:vs=\eEW:vt#8:xn:\e 409 :bs:cr=^M:dC#9:dT#8:nl=^J:ta=^I:pt: 410.Ed 411.Pp 412Entries may continue onto multiple lines by giving a \e as the last 413character of a line, and empty fields 414may be included for readability (here between the last field on a line 415and the first field on the next). 416Comments may be included on lines beginning with 417.Dq # . 418.Ss Types of Capabilities 419Capabilities in 420.Nm termcap 421are of three types: Boolean capabilities, 422which indicate particular features that the terminal has; 423numeric capabilities, 424giving the size of the display or the size of other attributes; 425and string capabilities, 426which give character sequences that can be used to perform particular 427terminal operations. 428All capabilities have two-letter codes. 429For instance, the fact that 430the Concept has 431.Em automatic margins 432(an automatic return and linefeed 433when the end of a line is reached) is indicated by the Boolean capability 434.Sy \&am . 435Hence the description of the Concept includes 436.Sy \&am . 437.Pp 438Numeric capabilities are followed by the character `#' then the value. 439In the example above 440.Sy \&co , 441which indicates the number of columns the display has, 442gives the value `80' for the Concept. 443.Pp 444Finally, string-valued capabilities, such as 445.Sy \&ce 446(clear-to-end-of-line 447sequence) are given by the two-letter code, an `=', then a string 448ending at the next following `:'. 449A delay in milliseconds may appear after 450the `=' in such a capability, 451which causes padding characters to be supplied by 452.Xr tputs 453after the remainder of the string is sent to provide this delay. 454The delay can be either a number, 455such as `20', or a number followed by 456an `*', 457such as `3*'. 458An `*' indicates that the padding required is proportional 459to the number of lines affected by the operation, and the amount given is 460the per-affected-line padding required. 461(In the case of insert-character, 462the factor is still the number of 463.Em lines 464affected; 465this is always 1 unless the terminal has 466.Sy \&in 467and the software uses it.) 468When an `*' is specified, it is sometimes useful to give a delay of the form 469`3.5' to specify a delay per line to tenths of milliseconds. 470(Only one decimal place is allowed.) 471.Pp 472A number of escape sequences are provided in the string-valued capabilities 473for easy encoding of control characters there. 474.Sy \&\eE 475maps to an 476.Dv ESC 477character, 478.Sy \&^X 479maps to a control-X for any appropriate X, 480and the sequences 481.Sy \&\en 482.Sy \&\er 483.Sy \&\et 484.Sy \&\eb 485.Sy \&\ef 486map to linefeed, return, tab, backspace, and formfeed, respectively. 487Finally, characters may be given as three octal digits after a 488.Sy \&\e , 489and the characters 490.Sy \&^ 491and 492.Sy \&\e 493may be given as 494.Sy \&\e^ 495and 496.Sy \&\e\e . 497If it is necessary to place a 498.Sy \&: 499in a capability it must be escaped in 500octal as 501.Sy \&\e072 . 502If it is necessary to place a 503.Dv NUL 504character in a string capability it 505must be encoded as 506.Sy \&\e200 . 507(The routines that deal with 508.Nm termcap 509use C strings and strip the high bits of the output very late, so that 510a 511.Sy \&\e200 512comes out as a 513.Sy \&\e000 514would.) 515.Pp 516Sometimes individual capabilities must be commented out. 517To do this, put a period before the capability name. 518For example, see the first 519.Sy \&cr 520and 521.Sy \&ta 522in the example above. 523.Ss Preparing Descriptions 524The most effective way to prepare a terminal description is by imitating 525the description of a similar terminal in 526.Nm termcap 527and to build up a description gradually, using partial descriptions 528with 529.Xr \&vi 530to check that they are correct. 531Be aware that a very unusual terminal may expose deficiencies in 532the ability of the 533.Nm termcap 534file to describe it 535or bugs in 536.Xr \&vi . 537To easily test a new terminal description you are working on 538you can put it in your home directory in a file called 539.Pa .termcap 540and programs will look there before looking in 541.Pa /usr/share/misc/termcap . 542You can also set the environment variable 543.Ev TERMPATH 544to a list of absolute file pathnames (separated by spaces or colons), 545one of which contains the description you are working on, 546and programs will search them in the order listed, and nowhere else. 547See 548.Xr termcap 3 . 549The 550.Ev TERMCAP 551environment variable is usually set to the 552.Nm termcap 553entry itself 554to avoid reading files when starting up a program. 555.Pp 556To get the padding for insert-line right 557(if the terminal manufacturer did not document it), 558a severe test is to use 559.Xr \&vi 560to edit 561.Pa /etc/passwd 562at 9600 baud, delete roughly 16 lines from the middle of the screen, 563then hit the `u' key several times quickly. 564If the display messes up, more padding is usually needed. 565A similar test can be used for insert-character. 566.Ss Basic Capabilities 567The number of columns on each line of the display is given by the 568.Sy \&co 569numeric capability. 570If the display is a 571.Tn CRT , 572then the 573number of lines on the screen is given by the 574.Sy \&li 575capability. 576If the display wraps around to the beginning of the next line when 577the cursor reaches the right margin, then it should have the 578.Sy \&am 579capability. 580If the terminal can clear its screen, 581the code to do this is given by the 582.Sy \&cl 583string capability. 584If the terminal overstrikes 585(rather than clearing the position when a character is overwritten), 586it should have the 587.Sy \&os 588capability. 589If the terminal is a printing terminal, 590with no soft copy unit, 591give it both 592.Sy \&hc 593and 594.Sy \&os . 595.Pf ( Sy \&os 596applies to storage scope terminals, 597such as the Tektronix 4010 series, 598as well as to hard copy and 599.Tn APL 600terminals.) 601If there is a code to move the cursor to the left edge of the current row, 602give this as 603.Sy \&cr . 604(Normally this will be carriage-return, 605.Sy \&^M . ) 606If there is a code to produce an audible signal (bell, beep, 607etc. ) , 608give this as 609.Sy \&bl . 610.Pp 611If there is a code (such as backspace) 612to move the cursor one position to the left, 613that capability should be given as 614.Sy \&le . 615Similarly, 616codes to move to the right, up, and down 617should be given as 618.Sy \&nd , 619.Sy \&up , 620and 621.Sy \&do , 622respectively. 623These 624.Em local cursor motions 625should not alter the text they pass over; 626for example, you would not normally use 627.Dq nd=\ \& 628unless the terminal has the 629.Sy \&os 630capability, 631because the space would erase the character moved over. 632.Pp 633A very important point here is that the local cursor motions encoded 634in 635.Nm termcap 636have undefined behavior at the left and top edges of a 637.Tn CRT 638display. 639Programs should never attempt to backspace around the left edge, 640unless 641.Sy \&bw 642is given, and never attempt to go up off the top 643using local cursor motions. 644.Pp 645In order to scroll text up, 646a program goes to the bottom left corner of the screen and sends the 647.Sy \&sf 648(index) string. 649To scroll text down, 650a program goes to the top left corner of the screen and sends the 651.Sy \&sr 652(reverse index) string. 653The strings 654.Sy \&sf 655and 656.Sy \&sr 657have undefined behavior 658when not on their respective corners of the screen. 659Parameterized versions of the scrolling sequences are 660.Sy \&SF 661and 662.Sy \&SR , 663which have the same semantics as 664.Sy \&sf 665and 666.Sy \&sr 667except that they take one parameter 668and scroll that many lines. 669They also have undefined behavior 670except at the appropriate corner of the screen. 671.Pp 672The 673.Sy \&am 674capability tells whether the cursor sticks at the right 675edge of the screen when text is output there, 676but this does not necessarily apply to 677.Sy \&nd 678from the last column. 679Leftward local motion is defined from the left edge only when 680.Sy \&bw 681is given; then an 682.Sy \&le 683from the left edge will move to the right edge of the previous row. 684This is useful for drawing a box around the edge of the screen, 685for example. 686If the terminal has switch-selectable automatic margins, 687the 688.Nm termcap 689description usually assumes that this feature is on, 690.Em i.e . , 691.Sy \&am . 692If the terminal has a command 693that moves to the first column of the next line, 694that command can be given as 695.Sy \&nw 696(newline). 697It is permissible for this to clear the remainder of the current line, 698so if the terminal has no correctly-working 699.Tn \&CR 700and 701.Tn \&LF 702it may still be possible to craft a working 703.Sy \&nw 704out of one or both of them. 705.Pp 706These capabilities suffice to describe hardcopy and 707.Dq glass-tty 708terminals. 709Thus the Teletype model 33 is described as 710.Bd -literal -offset indent 711T3\||\|tty33\||\|33\||\|tty\||\|Teletype model 33:\e 712 :bl=^G:co#72:cr=^M:do=^J:hc:os: 713.Ed 714.Pp 715and the Lear Siegler 716.Tn ADM Ns \-3 717is described as 718.Bd -literal -offset indent 719l3\||\|adm3\||\|3\||\|LSI \s-1ADM\s0-3:\e 720:am:bl=^G:cl=^Z:co#80:cr=^M:do=^J:le=^H:li#24:sf=^J: 721.Ed 722.Ss Parameterized Strings 723Cursor addressing and other strings requiring parameters 724are described by a 725parameterized string capability, with 726.Xr printf 3 Ns \-like 727escapes 728.Sy \&%x 729in it, 730while other characters are passed through unchanged. 731For example, to address the cursor the 732.Sy \&cm 733capability is given, using two parameters: the row and column to move to. 734(Rows and columns are numbered from zero and refer to the physical screen 735visible to the user, not to any unseen memory. 736If the terminal has memory-relative cursor addressing, 737that can be indicated by an analogous 738.Sy \&CM 739capability.) 740.Pp 741The 742.Sy \&% 743encodings have the following meanings: 744.Bl -column xxxxx 745.It "%% output `%'" 746.It "%d output value as in" 747.Xr printf 748%d 749.It "%2 output value as in" 750.Xr printf 751%2d 752.It "%3 output value as in" 753.Xr printf 754%3d 755.It "%. output value as in" 756.Xr printf 757%c 758.It "%+" Ns Em x Ta No add 759.Em x 760to value, then do %. 761.It "%>" Ns Em \&xy Ta No if 762value > 763.Em x 764then add 765.Em y , 766no output 767.It "%r reverse order of two parameters, no output" 768.It "%i increment by one, no output" 769.It "%n exclusive-or all parameters with 0140 (Datamedia 2500)" 770.It "%B" Ta Tn BCD No "(16*(value/10)) + (value%10), no output" 771.It "%D Reverse coding (value \- 2*(value%16)), no output (Delta Data)." 772.El 773.Pp 774Consider the Hewlett-Packard 2645, which, to get to row 3 and column 12, needs 775to be sent 776.Dq \eE&a12c03Y 777padded for 6 milliseconds. 778Note that the order 779of the row and column coordinates is reversed here 780and that the row and column 781are sent as two-digit integers. 782Thus its 783.Sy \&cm 784capability is 785.Dq Li cm=6\eE&%r%2c%2Y . 786.Pp 787The Datamedia 2500 needs the current row and column sent 788encoded in binary using 789.Dq \&%. . 790Terminals that use 791.Dq \&%. 792need to be able to 793backspace the cursor 794.Po Sy \&le Pc 795and to move the cursor up one line on the screen 796.Po Sy \&up Pc . 797This is necessary because it is not always safe to transmit 798.Sy \&\en , 799.Sy \&^D , 800and 801.Sy \&\er , 802as the system may change or discard them. 803(Programs using 804.Nm termcap 805must set terminal modes so that tabs are not expanded, so 806.Sy \&\et 807is safe to send. 808This turns out to be essential for the Ann Arbor 4080.) 809.Pp 810A final example is the Lear Siegler 811.Tn ADM Ns \-3a, 812which offsets row and column 813by a blank character, thus 814.Dq Li cm=\eE=%+ %+\ \& . 815.Pp 816Row or column absolute cursor addressing 817can be given as single parameter capabilities 818.Sy \&ch 819(horizontal position absolute) and 820.Sy \&cv 821(vertical position absolute). 822Sometimes these are shorter than the more general two-parameter sequence 823(as with the Hewlett-Packard 2645) and can be used in preference to 824.Sy \&cm . 825If there are parameterized local motions 826.Pf ( Em e.g . , 827move 828.Ar n 829positions to the right) 830these can be given as 831.Sy \&DO , 832.Sy \&LE , 833.Sy \&RI , 834and 835.Sy \&UP 836with a single parameter indicating how many positions to move. 837These are primarily useful if the terminal does not have 838.Sy \&cm , 839such as the Tektronix 4025. 840.Ss Cursor Motions 841.Pp 842If the terminal has a fast way to home the cursor 843(to the very upper left corner of the screen), this can be given as 844.Sy \&ho . 845Similarly, a fast way of getting to the lower left-hand corner 846can be given as 847.Sy \&ll ; 848this may involve going up with 849.Sy \&up 850from the home position, 851but a program should never do this itself (unless 852.Sy \&ll 853does), because it can 854make no assumption about the effect of moving up from the home position. 855Note that the home position is the same as 856cursor address (0,0): to the top left corner of the screen, not of memory. 857(Therefore, the 858.Dq \eEH 859sequence on Hewlett-Packard terminals 860cannot be used for 861.Sy \&ho . ) 862.Ss Area Clears 863If the terminal can clear from the current position to the end of the 864line, leaving the cursor where it is, this should be given as 865.Sy \&ce . 866If the terminal can clear from the current position to the end of the 867display, this should be given as 868.Sy \&cd . 869.Sy \&cd 870must only be invoked from the first column of a line. 871(Therefore, 872it can be simulated by a request to delete a large number of lines, 873if a true 874.Sy \&cd 875is not available.) 876.Ss Insert/Delete Line 877If the terminal can open a new blank line 878before the line containing the cursor, 879this should be given as 880.Sy \&al ; 881this must be invoked only from the first 882position of a line. 883The cursor must then appear at the left of the newly blank line. 884If the terminal can delete the line that the cursor is on, this 885should be given as 886.Sy \&dl ; 887this must only be used from the first position on 888the line to be deleted. 889Versions of 890.Sy \&al 891and 892.Sy \&dl 893which take a single parameter 894and insert or delete that many lines 895can be given as 896.Sy \&AL 897and 898.Sy \&DL . 899If the terminal has a settable scrolling region 900(like the VT100), 901the command to set this can be described with the 902.Sy \&cs 903capability, 904which takes two parameters: the top and bottom lines of the scrolling region. 905The cursor position is, alas, undefined after using this command. 906It is possible to get the effect of insert or delete line 907using this command \(em the 908.Sy \&sc 909and 910.Sy \&rc 911(save and restore cursor) commands are also useful. 912Inserting lines at the top or bottom of the screen can also be done using 913.Sy \&sr 914or 915.Sy \&sf 916on many terminals without a true insert/delete line, 917and is often faster even on terminals with those features. 918.Pp 919If the terminal has the ability to define a window as part of memory 920which all commands affect, it should be given as the parameterized string 921.Sy \&wi . 922The four parameters are the starting and ending lines in memory 923and the starting and ending columns in memory, in that order. 924(This 925.Xr terminfo 926capability is described for completeness. 927It is unlikely that any 928.Nm termcap Ns \- using 929program will support it.) 930.Pp 931If the terminal can retain display memory above the screen, then the 932.Sy \&da 933capability should be given; 934if display memory can be retained 935below, then 936.Sy \&db 937should be given. 938These indicate 939that deleting a line or scrolling may bring non-blank lines up from below 940or that scrolling back with 941.Sy \&sr 942may bring down non-blank lines. 943.Ss Insert/Delete Character 944There are two basic kinds of intelligent terminals with respect to 945insert/delete character that can be described using 946.Nm termcap . 947The most common insert/delete character operations affect only the characters 948on the current line and shift characters off the end of the line rigidly. 949Other terminals, such as the Concept\-100 and the Perkin Elmer Owl, make 950a distinction between typed and untyped blanks on the screen, shifting 951upon an insert or delete only to an untyped blank on the screen which is 952either eliminated or expanded to two untyped blanks. 953You can determine 954the kind of terminal you have by clearing the screen then typing 955text separated by cursor motions. 956Type 957.Dq Li abc\ \ \ \ def 958using local 959cursor motions (not spaces) between the 960.Dq abc 961and the 962.Dq def . 963Then position the cursor before the 964.Dq abc 965and put the terminal in insert 966mode. 967If typing characters causes the rest of the line to shift 968rigidly and characters to fall off the end, then your terminal does 969not distinguish between blanks and untyped positions. 970If the 971.Dq abc 972shifts over to the 973.Dq def 974which then move together around the end of the 975current line and onto the next as you insert, then you have the second type of 976terminal and should give the capability 977.Sy \&in , 978which stands for 979.Dq insert null . 980While these are two logically separate attributes 981(one line 982.Em \&vs . 983multi-line insert mode, 984and special treatment of untyped spaces), 985we have seen no terminals whose insert 986mode cannot be described with the single attribute. 987.Pp 988.Nm Termcap 989can describe both terminals that have an insert mode and terminals 990that send a simple sequence to open a blank position on the current line. 991Give as 992.Sy \&im 993the sequence to get into insert mode. 994Give as 995.Sy \&ei 996the sequence to leave insert mode. 997Now give as 998.Sy \&ic 999any sequence that needs to be sent just before 1000each character to be inserted. 1001Most terminals with a true insert mode 1002will not give 1003.Sy \&ic ; 1004terminals that use a sequence to open a screen 1005position should give it here. 1006(If your terminal has both, 1007insert mode is usually preferable to 1008.Sy \&ic . 1009Do not give both unless the terminal actually requires both to be used 1010in combination.) 1011If post-insert padding is needed, give this as a number of milliseconds 1012in 1013.Sy \&ip 1014(a string option). 1015Any other sequence that may need to be 1016sent after insertion of a single character can also be given in 1017.Sy \&ip . 1018If your terminal needs to be placed into an `insert mode' 1019and needs a special code preceding each inserted character, 1020then both 1021.Sy \&im Ns / Sy \&ei 1022and 1023.Sy \&ic 1024can be given, and both will be used. 1025The 1026.Sy \&IC 1027capability, with one parameter 1028.Em n , 1029will repeat the effects of 1030.Sy \&ic 1031.Em n 1032times. 1033.Pp 1034It is occasionally necessary to move around while in insert mode 1035to delete characters on the same line 1036.Pf ( Em e.g . , 1037if there is a tab after 1038the insertion position). 1039If your terminal allows motion while in 1040insert mode, you can give the capability 1041.Sy \&mi 1042to speed up inserting 1043in this case. 1044Omitting 1045.Sy \&mi 1046will affect only speed. 1047Some terminals 1048(notably Datamedia's) must not have 1049.Sy \&mi 1050because of the way their 1051insert mode works. 1052.Pp 1053Finally, you can specify 1054.Sy \&dc 1055to delete a single character, 1056.Sy \&DC 1057with one parameter 1058.Em n 1059to delete 1060.Em n 1061characters, 1062and delete mode by giving 1063.Sy \&dm 1064and 1065.Sy \&ed 1066to enter and exit delete mode 1067(which is any mode the terminal needs to be placed in for 1068.Sy \&dc 1069to work). 1070.Ss Highlighting, Underlining, and Visible Bells 1071If your terminal has one or more kinds of display attributes, 1072these can be represented in a number of different ways. 1073You should choose one display form as 1074.Em standout mode , 1075representing a good high-contrast, easy-on-the-eyes format 1076for highlighting error messages and other attention getters. 1077(If you have a choice, reverse video plus half-bright is good, 1078or reverse video alone.) 1079The sequences to enter and exit standout mode 1080are given as 1081.Sy \&so 1082and 1083.Sy \&se , 1084respectively. 1085If the code to change into or out of standout 1086mode leaves one or even two blank spaces or garbage characters on the screen, 1087as the 1088.Tn TVI 1089912 and Teleray 1061 do, 1090then 1091.Sy \&sg 1092should be given to tell how many characters are left. 1093.Pp 1094Codes to begin underlining and end underlining can be given as 1095.Sy \&us 1096and 1097.Sy \&ue , 1098respectively. 1099Underline mode change garbage is specified by 1100.Sy \&ug , 1101similar to 1102.Sy \&sg . 1103If the terminal has a code to underline the current character and move 1104the cursor one position to the right, 1105such as the Microterm Mime, 1106this can be given as 1107.Sy \&uc . 1108.Pp 1109Other capabilities to enter various highlighting modes include 1110.Sy \&mb 1111(blinking), 1112.Sy \&md 1113(bold or extra bright), 1114.Sy \&mh 1115(dim or half-bright), 1116.Sy \&mk 1117(blanking or invisible text), 1118.Sy \&mp 1119(protected), 1120.Sy \&mr 1121(reverse video), 1122.Sy \&me 1123(turn off 1124.Em all 1125attribute modes), 1126.Sy \&as 1127(enter alternate character set mode), and 1128.Sy \&ae 1129(exit alternate character set mode). 1130Turning on any of these modes singly may or may not turn off other modes. 1131.Pp 1132If there is a sequence to set arbitrary combinations of mode, 1133this should be given as 1134.Sy \&sa 1135(set attributes), taking 9 parameters. 1136Each parameter is either 0 or 1, 1137as the corresponding attributes is on or off. 1138The 9 parameters are, in order: standout, underline, reverse, blink, 1139dim, bold, blank, protect, and alternate character set. 1140Not all modes need be supported by 1141.Sy \&sa , 1142only those for which corresponding attribute commands exist. 1143(It is unlikely that a 1144.Nm termcap Ns \-using 1145program will support this capability, which is defined for compatibility 1146with 1147.Xr terminfo . ) 1148.Pp 1149Terminals with the 1150.Dq magic cookie 1151glitches 1152.Pf ( Sy \&sg 1153and 1154.Sy \&ug ) , 1155rather than maintaining extra attribute bits for each character cell, 1156instead deposit special 1157.Dq cookies , 1158or 1159.Dq garbage characters ,, 1160when they receive mode-setting sequences, 1161which affect the display algorithm. 1162.Pp 1163Some terminals, 1164such as the Hewlett-Packard 2621, 1165automatically leave standout 1166mode when they move to a new line or when the cursor is addressed. 1167Programs using standout mode 1168should exit standout mode on such terminals 1169before moving the cursor or sending a newline. 1170On terminals where this is not a problem, 1171the 1172.Sy \&ms 1173capability should be present 1174to say that this overhead is unnecessary. 1175.Pp 1176If the terminal has 1177a way of flashing the screen to indicate an error quietly 1178(a bell replacement), 1179this can be given as 1180.Sy \&vb ; 1181it must not move the cursor. 1182.Pp 1183If the cursor needs to be made more visible than normal 1184when it is not on the bottom line 1185(to change, for example, a non-blinking underline into an easier-to-find 1186block or blinking underline), 1187give this sequence as 1188.Sy \&vs . 1189If there is a way to make the cursor completely invisible, give that as 1190.Sy \&vi . 1191The capability 1192.Sy \&ve , 1193which undoes the effects of both of these modes, 1194should also be given. 1195.Pp 1196If your terminal correctly displays underlined characters 1197(with no special codes needed) 1198even though it does not overstrike, 1199then you should give the capability 1200.Sy \&ul . 1201If overstrikes are erasable with a blank, 1202this should be indicated by giving 1203.Sy \&eo . 1204.Ss Keypad 1205If the terminal has a keypad that transmits codes when the keys are pressed, 1206this information can be given. 1207Note that it is not possible to handle 1208terminals where the keypad only works in local mode 1209(this applies, for example, to the unshifted Hewlett-Packard 2621 keys). 1210If the keypad can be set to transmit or not transmit, 1211give these codes as 1212.Sy \&ks 1213and 1214.Sy \&ke . 1215Otherwise the keypad is assumed to always transmit. 1216The codes sent by the left-arrow, right-arrow, up-arrow, down-arrow, 1217and home keys can be given as 1218.Sy \&kl , 1219.Sy \&kr , 1220.Sy \&ku , 1221.Sy \&kd , 1222and 1223.Sy \&kh , 1224respectively. 1225If there are function keys such as f0, f1, ..., f9, the codes they send 1226can be given as 1227.Sy \&k0 , 1228.Sy \&k1 , 1229..., 1230.Sy \&k9 . 1231If these keys have labels other than the default f0 through f9, the labels 1232can be given as 1233.Sy \&l0 , 1234.Sy \&l1 , 1235..., 1236.Sy \&l9 . 1237The codes transmitted by certain other special keys can be given: 1238.Sy \&kH 1239(home down), 1240.Sy \&kb 1241(backspace), 1242.Sy \&ka 1243(clear all tabs), 1244.Sy \&kt 1245(clear the tab stop in this column), 1246.Sy \&kC 1247(clear screen or erase), 1248.Sy \&kD 1249(delete character), 1250.Sy \&kL 1251(delete line), 1252.Sy \&kM 1253(exit insert mode), 1254.Sy \&kE 1255(clear to end of line), 1256.Sy \&kS 1257(clear to end of screen), 1258.Sy \&kI 1259(insert character or enter insert mode), 1260.Sy \&kA 1261(insert line), 1262.Sy \&kN 1263(next page), 1264.Sy \&kP 1265(previous page), 1266.Sy \&kF 1267(scroll forward/down), 1268.Sy \&kR 1269(scroll backward/up), and 1270.Sy \&kT 1271(set a tab stop in this column). 1272In addition, if the keypad has a 3 by 3 array of keys 1273including the four arrow keys, then the other five keys can be given as 1274.Sy \&K1 , 1275.Sy \&K2 , 1276.Sy \&K3 , 1277.Sy \&K4 , 1278and 1279.Sy \&K5 . 1280These keys are useful when the effects of a 3 by 3 directional pad are needed. 1281The obsolete 1282.Sy \&ko 1283capability formerly used to describe 1284.Dq other 1285function keys has been 1286completely supplanted by the above capabilities. 1287.Pp 1288The 1289.Sy \&ma 1290entry is also used to indicate arrow keys on terminals that have 1291single-character arrow keys. 1292It is obsolete but still in use in 1293version 2 of 1294.Sy \&vi 1295which must be run on some minicomputers due to 1296memory limitations. 1297This field is redundant with 1298.Sy \&kl , 1299.Sy \&kr , 1300.Sy \&ku , 1301.Sy \&kd , 1302and 1303.Sy \&kh . 1304It consists of groups of two characters. 1305In each group, the first character is what an arrow key sends, and the 1306second character is the corresponding 1307.Sy \&vi 1308command. 1309These commands are 1310.Ar h 1311for 1312.Sy \&kl , 1313.Ar j 1314for 1315.Sy \&kd , 1316.Ar k 1317for 1318.Sy \&ku , 1319.Ar l 1320for 1321.Sy \&kr , 1322and 1323.Ar H 1324for 1325.Sy \&kh . 1326For example, the Mime would have 1327.Dq Li ma=^Hh^Kj^Zk^Xl 1328indicating arrow keys left (^H), down (^K), up (^Z), and right (^X). 1329(There is no home key on the Mime.) 1330.Ss Tabs and Initialization 1331If the terminal needs to be in a special mode when running 1332a program that uses these capabilities, 1333the codes to enter and exit this mode can be given as 1334.Sy \&ti 1335and 1336.Sy \&te . 1337This arises, for example, from terminals like the Concept with more than 1338one page of memory. 1339If the terminal has only memory-relative cursor addressing and not 1340screen-relative cursor addressing, 1341a screen-sized window must be fixed into 1342the display for cursor addressing to work properly. 1343This is also used for the Tektronix 4025, where 1344.Sy \&ti 1345sets the command character to be the one used by 1346.Nm termcap . 1347.Pp 1348Other capabilities 1349include 1350.Sy \&is , 1351an initialization string for the terminal, 1352and 1353.Sy \&if , 1354the name of a file containing long initialization strings. 1355These strings are expected to set the terminal into modes 1356consistent with the rest of the 1357.Nm termcap 1358description. 1359They are normally sent to the terminal by the 1360.Xr tset 1361program each time the user logs in. 1362They will be printed in the following order: 1363.Sy \&is ; 1364setting tabs using 1365.Sy \&ct 1366and 1367.Sy \&st ; 1368and finally 1369.Sy \&if . 1370.Pf ( Xr Terminfo 1371uses 1372.Sy \&i\&1-i2 1373instead of 1374.Sy \&is 1375and runs the program 1376.Sy \&iP 1377and prints 1378.Sy "\&i\&3" 1379after the other initializations.) 1380A pair of sequences that does a harder reset from a totally unknown state 1381can be analogously given as 1382.Sy \&rs 1383and 1384.Sy \&if . 1385These strings are output by the 1386.Xr reset 1387program, which is used when the terminal gets into a wedged state. 1388.Pf ( Xr Terminfo 1389uses 1390.Sy "\&r1-r3" 1391instead of 1392.Sy \&rs . ) 1393Commands are normally placed in 1394.Sy \&rs 1395and 1396.Sy \&rf 1397only if they produce annoying effects on the screen and are not necessary 1398when logging in. 1399For example, the command to set the VT100 into 80-column mode 1400would normally be part of 1401.Sy \&is , 1402but it causes an annoying glitch of the screen and is not normally needed 1403since the terminal is usually already in 80-column mode. 1404.Pp 1405If the terminal has hardware tabs, 1406the command to advance to the next tab stop can be given as 1407.Sy \&ta 1408(usually 1409.Sy \&^I ) . 1410A 1411.Dq backtab 1412command which moves leftward to the previous tab stop 1413can be given as 1414.Sy \&bt . 1415By convention, 1416if the terminal driver modes indicate that tab stops are being expanded 1417by the computer rather than being sent to the terminal, 1418programs should not use 1419.Sy \&ta 1420or 1421.Sy \&bt 1422even if they are present, 1423since the user may not have the tab stops properly set. 1424If the terminal has hardware tabs that are initially set every 1425.Ar n 1426positions when the terminal is powered up, then the numeric parameter 1427.Sy \&it 1428is given, showing the number of positions between tab stops. 1429This is normally used by the 1430.Xr tset 1431command to determine whether to set the driver mode for hardware tab 1432expansion, and whether to set the tab stops. 1433If the terminal has tab stops that can be saved in nonvolatile memory, the 1434.Nm termcap 1435description can assume that they are properly set. 1436.Pp 1437If there are commands to set and clear tab stops, they can be given as 1438.Sy \&ct 1439(clear all tab stops) and 1440.Sy \&st 1441(set a tab stop in the current column of every row). 1442If a more complex sequence is needed to set the tabs than can be 1443described by this, the sequence can be placed in 1444.Sy \&is 1445or 1446.Sy \&if . 1447.Ss Delays 1448Certain capabilities control padding in the terminal driver. 1449These are primarily needed by hardcopy terminals and are used by the 1450.Xr tset 1451program to set terminal driver modes appropriately. 1452Delays embedded in the capabilities 1453.Sy \&cr , 1454.Sy \&sf , 1455.Sy \&le , 1456.Sy \&ff , 1457and 1458.Sy \&ta 1459will cause the appropriate delay bits to be set in the terminal driver. 1460If 1461.Sy \&pb 1462(padding baud rate) is given, these values can be ignored at baud rates 1463below the value of 1464.Sy \&pb . 1465For 1466.Bx 4.2 1467.Xr tset , 1468the delays are given as numeric capabilities 1469.Sy \&dC , 1470.Sy \&dN , 1471.Sy \&dB , 1472.Sy \&dF , 1473and 1474.Sy \&dT 1475instead. 1476.Ss Miscellaneous 1477If the terminal requires other than a 1478.Dv NUL 1479(zero) character as a pad, 1480this can be given as 1481.Sy \&pc . 1482Only the first character of the 1483.Sy \&pc 1484string is used. 1485.Pp 1486If the terminal has commands to save and restore the position of the 1487cursor, give them as 1488.Sy \&sc 1489and 1490.Sy \&rc . 1491.Pp 1492If the terminal has an extra 1493.Dq status line 1494that is not normally used by 1495software, this fact can be indicated. 1496If the status line is viewed as an extra line below the bottom line, 1497then the capability 1498.Sy \&hs 1499should be given. 1500Special strings to go to a position in the status line and to return 1501from the status line can be given as 1502.Sy \&ts 1503and 1504.Sy \&fs . 1505.Pf ( Xr \&fs 1506must leave the cursor position in the same place that it was before 1507.Sy \&ts . 1508If necessary, the 1509.Sy \&sc 1510and 1511.Sy \&rc 1512strings can be included in 1513.Sy \&ts 1514and 1515.Sy \&fs 1516to get this effect.) 1517The capability 1518.Sy \&ts 1519takes one parameter, which is the column number of the status line 1520to which the cursor is to be moved. 1521If escape sequences and other special commands such as tab work while in 1522the status line, the flag 1523.Sy \&es 1524can be given. 1525A string that turns off the status line (or otherwise erases its contents) 1526should be given as 1527.Sy \&ds . 1528The status line is normally assumed to be the same width as the 1529rest of the screen, 1530.Em i.e . , 1531.Sy \&co . 1532If the status line is a different width (possibly because the terminal 1533does not allow an entire line to be loaded), then its width in columns 1534can be indicated with the numeric parameter 1535.Sy \&ws . 1536.Pp 1537If the terminal can move up or down half a line, this can be 1538indicated with 1539.Sy \&hu 1540(half-line up) and 1541.Sy \&hd 1542(half-line down). 1543This is primarily useful for superscripts and subscripts on hardcopy 1544terminals. 1545If a hardcopy terminal can eject to the next page (form feed), 1546give this as 1547.Sy \&ff 1548(usually 1549.Sy \&^L ) . 1550.Pp 1551If there is a command to repeat a given character a given number of times 1552(to save time transmitting a large number of identical characters), 1553this can be indicated with the parameterized string 1554.Sy \&rp . 1555The first parameter is the character to be repeated and the second is 1556the number of times to repeat it. 1557(This is a 1558.Xr terminfo 1559feature that is unlikely to be supported by a program that uses 1560.Nm termcap . ) 1561.Pp 1562If the terminal has a settable command character, such as the 1563Tektronix 4025, this can be indicated with 1564.Sy \&CC . 1565A prototype command character is chosen which is used in all capabilities. 1566This character is given in the 1567.Sy \&CC 1568capability to identify it. 1569The following convention is supported on some 1570.Ux 1571systems: 1572The environment is to be searched for a 1573.Ev \&CC 1574variable, 1575and if found, 1576all occurrences of the prototype character are replaced by the character 1577in the environment variable. 1578This use of the 1579.Ev \&CC 1580environment variable 1581is a very bad idea, as it conflicts with 1582.Xr make 1 . 1583.Pp 1584Terminal descriptions that do not represent a specific kind of known 1585terminal, such as 1586.Em switch , 1587.Em dialup , 1588.Em patch , 1589and 1590.Xr network , 1591should include the 1592.Sy \&gn 1593(generic) capability so that programs can complain that they do not know 1594how to talk to the terminal. 1595(This capability does not apply to 1596.Em virtual 1597terminal descriptions for which the escape sequences are known.) 1598.Pp 1599If the terminal uses xoff/xon 1600.Pq Tn DC3 Ns / Ns Tn DC1 1601handshaking for flow control, give 1602.Sy \&xo . 1603Padding information should still be included so that routines can make 1604better decisions about costs, but actual pad characters will not be 1605transmitted. 1606.Pp 1607If the terminal has a 1608.Dq meta key 1609which acts as a shift key, setting the 16108th bit of any character transmitted, then this fact can be indicated with 1611.Sy \&km . 1612Otherwise, software will assume that the 8th bit is parity and it will 1613usually be cleared. 1614If strings exist to turn this 1615.Dq meta mode 1616on and off, they can be given as 1617.Sy \&mm 1618and 1619.Sy \&mo . 1620.Pp 1621If the terminal has more lines of memory than will fit on the screen at once, 1622the number of lines of memory can be indicated with 1623.Sy \&lm . 1624An explicit value of 0 indicates that the number of lines is not fixed, 1625but that there is still more memory than fits on the screen. 1626.Pp 1627If the terminal is one of those supported by the 1628.Ux 1629system virtual 1630terminal protocol, the terminal number can be given as 1631.Sy \&vt . 1632.Pp 1633Media copy strings which control an auxiliary printer 1634connected to the terminal can be given as 1635.Sy \&ps : 1636print the contents of the screen; 1637.Sy \&pf : 1638turn off the printer; and 1639.Sy \&po : 1640turn on the printer. 1641When the printer is on, all text sent to the terminal will be sent to the 1642printer. 1643It is undefined whether the text is also displayed on the terminal screen 1644when the printer is on. 1645A variation 1646.Sy \&pO 1647takes one parameter and leaves the printer on for as many characters as the 1648value of the parameter, then turns the printer off. 1649The parameter should not exceed 255. 1650All text, including 1651.Sy \&pf , 1652is transparently passed to the printer while 1653.Sy \&pO 1654is in effect. 1655.Pp 1656Strings to program function keys can be given as 1657.Sy \&pk , 1658.Sy \&pl , 1659and 1660.Sy \&px . 1661Each of these strings takes two parameters: the function key number 1662to program (from 0 to 9) and the string to program it with. 1663Function key numbers out of this range may program undefined keys 1664in a terminal-dependent manner. 1665The differences among the capabilities are that 1666.Sy \&pk 1667causes pressing the given key to be the same as the user typing the given 1668string; 1669.Sy \&pl 1670causes the string to be executed by the terminal in local mode; 1671and 1672.Sy \&px 1673causes the string to be transmitted to the computer. 1674Unfortunately, due to lack of a definition for string parameters in 1675.Nm termcap , 1676only 1677.Xr terminfo 1678supports these capabilities. 1679.Ss Glitches and Braindamage 1680Hazeltine terminals, which do not allow `~' characters to be displayed, 1681should indicate 1682.Sy \&hz . 1683.Pp 1684The 1685.Sy \&nc 1686capability, now obsolete, formerly indicated Datamedia terminals, 1687which echo 1688.Sy \&\er \en 1689for 1690carriage return then ignore a following linefeed. 1691.Pp 1692Terminals that ignore a linefeed immediately after an 1693.Sy \&am 1694wrap, such as the Concept, should indicate 1695.Sy \&xn . 1696.Pp 1697If 1698.Sy \&ce 1699is required to get rid of standout 1700(instead of merely writing normal text on top of it), 1701.Sy \&xs 1702should be given. 1703.Pp 1704Teleray terminals, where tabs turn all characters moved over to blanks, 1705should indicate 1706.Sy \&xt 1707(destructive tabs). 1708This glitch is also taken to mean that it is not possible 1709to position the cursor on top of a \*(lqmagic cookie\*(rq, and that 1710to erase standout mode it is necessary to use delete and insert line. 1711.Pp 1712The Beehive Superbee, which is unable to correctly transmit the 1713.Dv ESC 1714or 1715.Sy \&^C 1716characters, has 1717.Sy \&xb , 1718indicating that the 1719.Dq \&f\&1 1720key is used for 1721.Dv ESC 1722and 1723.Dq \&f\&2 1724for ^C. 1725(Only certain Superbees have this problem, depending on the 1726.Tn ROM . ) 1727.Pp 1728Other specific terminal problems may be corrected by adding more 1729capabilities of the form 1730.Sy x Em x . 1731.Ss Similar Terminals 1732If there are two very similar terminals, 1733one can be defined as being just like the other with certain exceptions. 1734The string capability 1735.Sy \&tc 1736can be given 1737with the name of the similar terminal. 1738This capability must be 1739.Em last , 1740and the combined length of the entries 1741must not exceed 1024. 1742The capabilities given before 1743.Sy \&tc 1744override those in the terminal type invoked by 1745.Sy \&tc . 1746A capability can be canceled by placing 1747.Sy \&xx@ 1748to the left of the 1749.Sy \&tc 1750invocation, where 1751.Sy \&xx 1752is the capability. 1753For example, the entry 1754.Bd -literal -offset indent 1755hn\||\|2621\-nl:ks@:ke@:tc=2621: 1756.Ed 1757.Pp 1758defines a 1759.Dq 2621\-nl 1760that does not have the 1761.Sy \&ks 1762or 1763.Sy \&ke 1764capabilities, 1765hence does not turn on the function key labels when in visual mode. 1766This is useful for different modes for a terminal, or for different 1767user preferences. 1768.Sh FILES 1769.Bl -tag -width /usr/share/misc/termcap.db -compact 1770.It Pa /usr/share/misc/termcap 1771File containing terminal descriptions. 1772.It Pa /usr/share/misc/termcap.db 1773Hash database file containing terminal descriptions (see 1774.Xr cap_mkdb 1 ) . 1775.El 1776.Sh SEE ALSO 1777.Xr \&ex 1 , 1778.Xr cap_mkdb 1 , 1779.Xr more 1 , 1780.Xr tset 1 , 1781.Xr \&ul 1 , 1782.Xr vi 1 , 1783.Xr curses 3 , 1784.Xr printf 3 , 1785.Xr termcap 3 , 1786.Xr term 7 1787.Sh CAVEATS AND BUGS 1788The 1789.Em Note : 1790.Nm termcap 1791functions 1792were replaced by 1793.Xr terminfo 1794in 1795.At V 1796Release 2.0. 1797The transition will be relatively painless if capabilities flagged as 1798.Dq obsolete 1799are avoided. 1800.Pp 1801Lines and columns are now stored by the kernel as well as in the termcap 1802entry. 1803Most programs now use the kernel information primarily; the information 1804in this file is used only if the kernel does not have any information. 1805.Pp 1806.Xr \&Vi 1807allows only 256 characters for string capabilities, and the routines 1808in 1809.Xr termlib 3 1810do not check for overflow of this buffer. 1811The total length of a single entry (excluding only escaped newlines) 1812may not exceed 1024. 1813.Pp 1814Not all programs support all entries. 1815.Sh HISTORY 1816The 1817.Nm 1818file format appeared in 1819.Bx 3 . 1820