.\" Copyright (c) 1980 Regents of the University of California.

.\" All rights reserved. The Berkeley software License Agreement

.\" specifies the terms and conditions for redistribution.

.\"

.\" @(#)termcap.5 6.4 (Berkeley) 5/15/86

.\"

.tr ||

.tr *\(**

.TH TERMCAP 5 "1 November 1985"

.UC

.SH NAME

termcap \- terminal capability data base

.SH SYNOPSIS

.B /etc/termcap

.SH DESCRIPTION

.B Termcap\^

is a data base describing terminals,

used,

.IR e.g. ,

by

.BR vi\^ (1)

and

.BR curses\^ (3).

Terminals are described in

.B termcap\^

by giving a set of capabilities that they have and by describing

how operations are performed.

Padding requirements and initialization sequences

are included in

.BR termcap\^ .

.PP

Entries in

.B termcap\^

consist of a number of `:'-separated fields.

The first entry for each terminal gives the names that are known for the

terminal, separated by `|' characters.

The first name is always two characters

long and is used by older systems which store the terminal type

in a 16-bit word in a system-wide data base.

The second name given is the most common abbreviation for the terminal,

the last name given should be a long name fully identifying the terminal,

and all others are understood as synonyms for the terminal name.

All names but the first and last

should be in lower case and contain no blanks;

the last name may well contain

upper case and blanks for readability.

.PP

Terminal names (except for the last, verbose entry)

should be chosen using the following conventions.

The particular piece of hardware making up the terminal

should have a root name chosen, thus \*(lqhp2621\*(rq.

This name should not contain hyphens.

Modes that the hardware can be in

or user preferences

should be indicated by appending a hyphen and an indicator of the mode.

Therefore, a \*(lqvt100\*(rq in 132-column mode would be \*(lqvt100-w\*(rq.

The following suffixes should be used where possible:

.sp

.ta

.if t .ta \w'\fBSuffix\fP\ \ \ 'u +\w'With automatic margins (usually default)\ \ 'u

.if n .ta \w'Suffix\ \ \ 'u +\w'With automatic margins (usually default)\ \ 'u

.nf

.if t .nr Xx \n(.lu-\n(.i-\w'\fBSuffix\fP\ \ \ With automatic margins (usually default)\ \ vt100-am'u

.if t .in +\n(Xxu/2u

\fBSuffix Meaning Example\fP

-w Wide mode (more than 80 columns) vt100-w

-am With automatic margins (usually default) vt100-am

-nam Without automatic margins vt100-nam

-\fIn\fP Number of lines on the screen aaa-60

-na No arrow keys (leave them in local) concept100-na

-\fIn\^\fPp Number of pages of memory concept100-4p

-rv Reverse video concept100-rv

.fi

.SH CAPABILITIES

.PP

The characters in the

.B Notes

field in the table have the following meanings

(more than one may apply to a capability):

.PP

.ta

.ta \w'N\ \ \ 'u

.nr fi \w'N\ \ \ '

.in +\n(fiu

.ti -\n(fiu

N indicates numeric parameter(s)

.ti -\n(fiu

P indicates that padding may be specified

.ti -\n(fiu

* indicates that padding may be based on the number of lines affected

.ti -\n(fiu

o indicates capability is obsolete

.in +\n(fiu

.PP

\*(lqObsolete\*(rq capabilities have no

.B terminfo\^

equivalents,

since they were considered useless,

or are subsumed by other capabilities.

New software should not rely on them at all.

.PP

.if t .ta \w'\fBName \fP'u +\w'\fBType \fP'u +\w'\fBNotes \fP'u

.if n .ta \w'Name 'u +\w'Type 'u +\w'Notes 'u \" Cawf troubled by \w'\fB

.if t .nr fi \w'\fBName Type Notes \fP'

.if n .nr fi \w'Name Type Notes '

.in +\n(fiu

.ti -\n(fiu

\fBName Type Notes Description\fP

.ti -\n(fiu

ae str (P) End alternate character set

.ti -\n(fiu

AL str (NP*) Add \fIn\^\fP new blank lines

.ti -\n(fiu

al str (P*) Add new blank line

.ti -\n(fiu

am bool Terminal has automatic margins

.ti -\n(fiu

as str (P) Start alternate character set

.ti -\n(fiu

bc str (o) Backspace if not \fB^H\fP

.ti -\n(fiu

bl str (P) Audible signal (bell)

.ti -\n(fiu

bs bool (o) Terminal can backspace with \fB^H\fP

.ti -\n(fiu

bt str (P) Back tab

.ti -\n(fiu

bw bool \fBle\fP (backspace) wraps from column 0 to last column

.ti -\n(fiu

CC str Terminal settable command character in prototype

.ti -\n(fiu

cd str (P*) Clear to end of display

.ti -\n(fiu

ce str (P) Clear to end of line

.ti -\n(fiu

ch str (NP) Set cursor column (horizontal position)

.ti -\n(fiu

cl str (P*) Clear screen and home cursor

.ti -\n(fiu

CM str (NP) Memory-relative cursor addressing

.ti -\n(fiu

cm str (NP) Screen-relative cursor motion

.ti -\n(fiu

co num Number of columns in a line (See BUGS section below)

.ti -\n(fiu

cr str (P) Carriage return

.ti -\n(fiu

cs str (NP) Change scrolling region (VT100)

.ti -\n(fiu

ct str (P) Clear all tab stops

.ti -\n(fiu

cv str (NP) Set cursor row (vertical position)

.ti -\n(fiu

da bool Display may be retained above the screen

.ti -\n(fiu

dB num (o) Milliseconds of \fBbs\fP delay needed (default 0)

.ti -\n(fiu

db bool Display may be retained below the screen

.ti -\n(fiu

DC str (NP*) Delete \fIn\^\fP characters

.ti -\n(fiu

dC num (o) Milliseconds of \fBcr\fP delay needed (default 0)

.ti -\n(fiu

dc str (P*) Delete character

.ti -\n(fiu

dF num (o) Milliseconds of \fBff\fP delay needed (default 0)

.ti -\n(fiu

DL str (NP*) Delete \fIn\^\fP lines

.ti -\n(fiu

dl str (P*) Delete line

.ti -\n(fiu

dm str Enter delete mode

.ti -\n(fiu

dN num (o) Milliseconds of \fBnl\fP delay needed (default 0)

.ti -\n(fiu

DO str (NP*) Move cursor down \fIn\^\fP lines

.ti -\n(fiu

do str Down one line

.ti -\n(fiu

ds str Disable status line

.ti -\n(fiu

dT num (o) Milliseconds of horizontal tab delay needed (default 0)

.ti -\n(fiu

dV num (o) Milliseconds of vertical tab delay needed (default 0)

.ti -\n(fiu

ec str (NP) Erase \fIn\^\fP characters

.ti -\n(fiu

ed str End delete mode

.ti -\n(fiu

ei str End insert mode

.ti -\n(fiu

eo bool Can erase overstrikes with a blank

.ti -\n(fiu

EP bool (o) Even parity

.ti -\n(fiu

es bool Escape can be used on the status line

.ti -\n(fiu

ff str (P*) Hardcopy terminal page eject

.ti -\n(fiu

fs str Return from status line

.ti -\n(fiu

gn bool Generic line type (\fIe.g.\fP dialup, switch)

.ti -\n(fiu

hc bool Hardcopy terminal

.ti -\n(fiu

HD bool (o) Half-duplex

.ti -\n(fiu

hd str Half-line down (forward 1/2 linefeed)

.ti -\n(fiu

ho str (P) Home cursor

.ti -\n(fiu

hs bool Has extra \*(lqstatus line\*(rq

.ti -\n(fiu

hu str Half-line up (reverse 1/2 linefeed)

.ti -\n(fiu

hz bool Cannot print ~s (Hazeltine)

.ti -\n(fiu

i1-i3 str Terminal initialization strings (\fBterminfo\^\fP only)

.ti -\n(fiu

IC str (NP*) Insert \fIn\^\fP blank characters

.ti -\n(fiu

ic str (P*) Insert character

.ti -\n(fiu

if str Name of file containing initialization string

.ti -\n(fiu

im str Enter insert mode

.ti -\n(fiu

in bool Insert mode distinguishes nulls

.ti -\n(fiu

iP str Pathname of program for initialization (\fBterminfo\^\fP only)

.ti -\n(fiu

ip str (P*) Insert pad after character inserted

.ti -\n(fiu

is str Terminal initialization string (\fBtermcap\^\fP only)

.ti -\n(fiu

it num Tabs initially every \fIn\^\fP positions

.ti -\n(fiu

K1 str Sent by keypad upper left

.ti -\n(fiu

K2 str Sent by keypad upper right

.ti -\n(fiu

K3 str Sent by keypad center

.ti -\n(fiu

K4 str Sent by keypad lower left

.ti -\n(fiu

K5 str Sent by keypad lower right

.ti -\n(fiu

k0-k9 str Sent by function keys 0-9

.ti -\n(fiu

kA str Sent by insert-line key

.ti -\n(fiu

ka str Sent by clear-all-tabs key

.ti -\n(fiu

kb str Sent by backspace key

.ti -\n(fiu

kC str Sent by clear-screen or erase key

.ti -\n(fiu

kD str Sent by delete-character key

.ti -\n(fiu

kd str Sent by down-arrow key

.ti -\n(fiu

kE str Sent by clear-to-end-of-line key

.ti -\n(fiu

ke str Out of \*(lqkeypad transmit\*(rq mode

.ti -\n(fiu

kF str Sent by scroll-forward/down key

.ti -\n(fiu

kH str Sent by home-down key

.ti -\n(fiu

kh str Sent by home key

.ti -\n(fiu

kI str Sent by insert-character or enter-insert-mode key

.ti -\n(fiu

kL str Sent by delete-line key

.ti -\n(fiu

kl str Sent by left-arrow key

.ti -\n(fiu

kM str Sent by insert key while in insert mode

.ti -\n(fiu

km bool Has a \*(lqmeta\*(rq key (shift, sets parity bit)

.ti -\n(fiu

kN str Sent by next-page key

.ti -\n(fiu

kn num (o) Number of function (\fBk0\fP\-\fBk9\fP) keys (default 0)

.ti -\n(fiu

ko str (o) Termcap entries for other non-function keys

.ti -\n(fiu

kP str Sent by previous-page key

.ti -\n(fiu

kR str Sent by scroll-backward/up key

.ti -\n(fiu

kr str Sent by right-arrow key

.ti -\n(fiu

kS str Sent by clear-to-end-of-screen key

.ti -\n(fiu

ks str Put terminal in \*(lqkeypad transmit\*(rq mode

.ti -\n(fiu

kT str Sent by set-tab key

.ti -\n(fiu

kt str Sent by clear-tab key

.ti -\n(fiu

ku str Sent by up-arrow key

.ti -\n(fiu

l0-l9 str Labels on function keys if not \*(lqf\fIn\^\fP\*(rq

.ti -\n(fiu

LC bool (o) Lower-case only

.ti -\n(fiu

LE str (NP) Move cursor left \fIn\^\fP positions

.ti -\n(fiu

le str (P) Move cursor left one position

.ti -\n(fiu

li num Number of lines on screen or page (See BUGS section below)

.ti -\n(fiu

ll str Last line, first column

.ti -\n(fiu

lm num Lines of memory if > \fBli\fP (0 means varies)

.ti -\n(fiu

ma str (o) Arrow key map (used by \fBvi\^\fP version 2 only)

.ti -\n(fiu

mb str Turn on blinking attribute

.ti -\n(fiu

md str Turn on bold (extra bright) attribute

.ti -\n(fiu

me str Turn off all attributes

.ti -\n(fiu

mh str Turn on half-bright attribute

.ti -\n(fiu

mi bool Safe to move while in insert mode

.ti -\n(fiu

mk str Turn on blank attribute (characters invisible)

.ti -\n(fiu

ml str (o) Memory lock on above cursor

.ti -\n(fiu

mm str Turn on \*(lqmeta mode\*(rq (8th bit)

.ti -\n(fiu

mo str Turn off \*(lqmeta mode\*(rq

.ti -\n(fiu

mp str Turn on protected attribute

.ti -\n(fiu

mr str Turn on reverse-video attibute

.ti -\n(fiu

ms bool Safe to move in standout modes

.ti -\n(fiu

mu str (o) Memory unlock (turn off memory lock)

.ti -\n(fiu

nc bool (o) No correctly-working \fBcr\fP (Datamedia 2500, Hazeltine 2000)

.ti -\n(fiu

nd str Non-destructive space (cursor right)

.ti -\n(fiu

NL bool (o) \fB\\n\fP is newline, not line feed

.ti -\n(fiu

nl str (o) Newline character if not \fB\\n\fP

.ti -\n(fiu

ns bool (o) Terminal is a \s-1CRT\s0 but doesn't scroll

.ti -\n(fiu

nw str (P) Newline (behaves like \fBcr\fP followed by \fBdo\fP)

.ti -\n(fiu

OP bool (o) Odd parity

.ti -\n(fiu

os bool Terminal overstrikes

.ti -\n(fiu

pb num Lowest baud where delays are required

.ti -\n(fiu

pc str Pad character (default \s-2NUL\s0)

.ti -\n(fiu

pf str Turn off the printer

.ti -\n(fiu

pk str Program function key \fIn\^\fP to type string \fIs\fP (\fBterminfo\^\fP only)

.ti -\n(fiu

pl str Program function key \fIn\^\fP to execute string \fIs\fP (\fBterminfo\^\fP only)

.ti -\n(fiu

pO str (N) Turn on the printer for \fIn\^\fP bytes

.ti -\n(fiu

po str Turn on the printer

.ti -\n(fiu

ps str Print contents of the screen

.ti -\n(fiu

pt bool (o) Has hardware tabs (may need to be set with \fBis\fP)

.ti -\n(fiu

px str Program function key \fIn\^\fP to transmit string \fIs\fP (\fBterminfo\^\fP only)

.ti -\n(fiu

r1-r3 str Reset terminal completely to sane modes (\fBterminfo\^\fP only)

.ti -\n(fiu

rc str (P) Restore cursor to position of last \fBsc\fP

.ti -\n(fiu

rf str Name of file containing reset codes

.ti -\n(fiu

RI str (NP) Move cursor right \fIn\^\fP positions

.ti -\n(fiu

rp str (NP*) Repeat character \fIc n\^\fP times

.ti -\n(fiu

rs str Reset terminal completely to sane modes (\fBtermcap\^\fP only)

.ti -\n(fiu

sa str (NP) Define the video attributes

.ti -\n(fiu

sc str (P) Save cursor position

.ti -\n(fiu

se str End standout mode

.ti -\n(fiu

SF str (NP*) Scroll forward \fIn\^\fP lines

.ti -\n(fiu

sf str (P) Scroll text up

.ti -\n(fiu

sg num Number of garbage chars left by \fBso\fP or \fBse\fP (default 0)

.ti -\n(fiu

so str Begin standout mode

.ti -\n(fiu

SR str (NP*) Scroll backward \fIn\^\fP lines

.ti -\n(fiu

sr str (P) Scroll text down

.ti -\n(fiu

st str Set a tab in all rows, current column

.ti -\n(fiu

ta str (P) Tab to next 8-position hardware tab stop

.ti -\n(fiu

tc str Entry of similar terminal \- must be last

.ti -\n(fiu

te str String to end programs that use \fBtermcap\fP

.ti -\n(fiu

ti str String to begin programs that use \fBtermcap\fP

.ti -\n(fiu

ts str (N) Go to status line, column \fIn\^\fP

.ti -\n(fiu

UC bool (o) Upper-case only

.ti -\n(fiu

uc str Underscore one character and move past it

.ti -\n(fiu

ue str End underscore mode

.ti -\n(fiu

ug num Number of garbage chars left by \fBus\fP or \fBue\fP (default 0)

.ti -\n(fiu

ul bool Underline character overstrikes

.ti -\n(fiu

UP str (NP*) Move cursor up \fIn\^\fP lines

.ti -\n(fiu

up str Upline (cursor up)

.ti -\n(fiu

us str Start underscore mode

.ti -\n(fiu

vb str Visible bell (must not move cursor)

.ti -\n(fiu

ve str Make cursor appear normal (undo \fBvs\fP/\fBvi\fP)

.ti -\n(fiu

vi str Make cursor invisible

.ti -\n(fiu

vs str Make cursor very visible

.ti -\n(fiu

vt num Virtual terminal number (not supported on all systems)

.ti -\n(fiu

wi str (N) Set current window

.ti -\n(fiu

ws num Number of columns in status line

.ti -\n(fiu

xb bool Beehive (f1=\s-2ESC\s0, f2=^C)

.ti -\n(fiu

xn bool Newline ignored after 80 cols (Concept)

.ti -\n(fiu

xo bool Terminal uses xoff/xon (\s-2DC3\s0/\s-2DC1\s0) handshaking

.ti -\n(fiu

xr bool (o) Return acts like \fBce cr nl\fP (Delta Data)

.ti -\n(fiu

xs bool Standout not erased by overwriting (Hewlett-Packard)

.ti -\n(fiu

xt bool Tabs ruin, magic \fBso\fP char (Teleray 1061)

.ti -\n(fiu

xx bool (o) Tektronix 4025 insert-line

.in -\n(fiu

.PP

.B A Sample Entry

.PP

The following entry, which describes the Concept\-100, is among the more

complex entries in the

.B termcap\^

file as of this writing.

.PP

.nf

.if t .ta 8n +8n

.if n .ta 2n +2n

ca\||\|concept100\||\|c100\||\|concept\||\|c104\||\|concept100-4p\||\|HDS Concept\-100:\e

:al=3*\eE^R:am:bl=^G:cd=16*\eE^C:ce=16\eE^U:cl=2*^L:cm=\eEa%+ %+ :\e

: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

:ip=16*:is=\eEU\eEf\eE7\eE5\eE8\eEl\eENH\eEK\eE\e200\eEo&\e200\eEo\e47\eE:k1=\eE5:\e

:k2=\eE6:k3=\eE7:kb=^h:kd=\eE<:ke=\eEx:kh=\eE?:kl=\eE>:kr=\eE=:ks=\eEX:\e

:ku=\eE;:le=^H:li#24:mb=\eEC:me=\eEN\e200:mh=\eEE:mi:mk=\eEH:mp=\eEI:\e

:mr=\eED:nd=\eE=:pb#9600:rp=0.2*\eEr%.%+ :se=\eEd\eEe:sf=^J:so=\eEE\eED:\e

:.ta=8\et:te=\eEv \e200\e200\e200\e200\e200\e200\eEp\er\en:\e

:ti=\eEU\eEv 8p\eEp\er:ue=\eEg:ul:up=\eE;:us=\eEG:\e

:vb=\eEk\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\e200\eEK:\e

:ve=\eEw:vs=\eEW:vt#8:xn:\e

:bs:cr=^M:dC#9:dT#8:nl=^J:ta=^I:pt:

.fi

.PP

Entries may continue onto multiple lines by giving a \e as the last

character of a line, and empty fields

may be included for readability (here between the last field on a line

and the first field on the next).

Comments may be included on lines beginning with \*(lq#\*(rq.

.br

.ne 5

.PP

.B Types of Capabilities

.PP

Capabilities in

.B termcap\^

are of three types: Boolean capabilities,

which indicate particular features that the terminal has;

numeric capabilities,

giving the size of the display or the size of other attributes;

and string capabilities,

which give character sequences that can be used to perform particular

terminal operations.

All capabilities have two-letter codes.

For instance, the fact that

the Concept has

.I automatic margins

.RI ( i.e. ,

an automatic return and linefeed

when the end of a line is reached) is indicated by the Boolean capability

.BR am .

Hence the description of the Concept includes

.BR am .

.PP

Numeric capabilities are followed by the character `#' then the value.

In the example above

.BR co ,

which indicates the number of columns the display has,

gives the value `80' for the Concept.

.PP

Finally, string-valued capabilities, such as

.B ce

(clear-to-end-of-line

sequence) are given by the two-letter code, an `=', then a string

ending at the next following `:'.

A delay in milliseconds may appear after

the `=' in such a capability,

which causes padding characters to be supplied by

.B tputs\^

after the remainder of the string is sent to provide this delay.

The delay can be either a number,

.I e.g.

`20', or a number followed by

an `*',

.IR i.e. ,

`3*'.

An `*' indicates that the padding required is proportional

to the number of lines affected by the operation, and the amount given is

the per-affected-line padding required.

(In the case of insert-character,

the factor is still the number of

.I lines\^

affected;

this is always 1 unless the terminal has

.B in

and the software uses it.)

When an `*' is specified, it is sometimes useful to give a delay of the form

`3.5' to specify a delay per line to tenths of milliseconds.

(Only one decimal place is allowed.)

.PP

A number of escape sequences are provided in the string-valued capabilities

for easy encoding of control characters there.

.B \eE

maps to an \s-2ESC\s0

character,

.B ^X

maps to a control-X for any appropriate X,

and the sequences

.B \en

.B \er

.B \et

.B \eb

.B \ef

map to linefeed, return, tab, backspace, and formfeed, respectively.

Finally, characters may be given as three octal digits after a

.BR \e ,

and the characters

.B ^

and

.B \e

may be given as

.B \e^

and

.BR \e\e .

If it is necessary to place a

.B :

in a capability it must be escaped in

octal as

.BR \e072 .

If it is necessary to place a \s-2NUL\s0

character in a string capability it

must be encoded as

.BR \e200 .

(The routines that deal with

.B termcap\^

use C strings and strip the high bits of the output very late, so that

a

.B \e200

comes out as a

.B \e000

would.)

.PP

Sometimes individual capabilities must be commented out.

To do this, put a period before the capability name.

For example, see the first

.B cr

and

.B ta

in the example above.

.br

.ne 5

.PP

.B Preparing Descriptions

.PP

We now outline how to prepare descriptions of terminals.

The most effective way to prepare a terminal description is by imitating

the description of a similar terminal in

.B termcap\^

and to build up a description gradually, using partial descriptions

with

.B vi\^

to check that they are correct.

Be aware that a very unusual terminal may expose deficiencies in

the ability of the

.B termcap\^

file to describe it

or bugs in

.BR vi\^ .

To easily test a new terminal description you can set the environment variable

.B

.SM TERMCAP

to the absolute pathname of a file containing the description you are working

on and programs will look there rather than in

.BR /etc/termcap\^ .

.B

.SM TERMCAP

can also be set to the

.B termcap\^

entry itself

to avoid reading the file when starting up a program.

.PP

To get the padding for insert-line right

(if the terminal manufacturer did not document it),

a severe test is to use

.B vi\^

to edit

.B /etc/passwd\^

at 9600 baud, delete roughly 16 lines from the middle of the screen,

then hit the `u' key several times quickly.

If the display messes up, more padding is usually needed.

A similar test can be used for insert-character.

.br

.ne 5

.PP

.B Basic Capabilities

.PP

The number of columns on each line of the display is given by the

.B co

numeric capability.

If the display is a \s-1CRT\s0, then the

number of lines on the screen is given by the

.B li

capability.

If the display wraps around to the beginning of the next line when

the cursor reaches the right margin, then it should have the

.B am

capability.

If the terminal can clear its screen,

the code to do this is given by the

.B cl

string capability.

If the terminal overstrikes

(rather than clearing the position when a character is overwritten),

it should have the

.B os

capability.

If the terminal is a printing terminal,

with no soft copy unit,

give it both

.B hc

and

.BR os .

.RB ( os

applies to storage scope terminals,

such as the Tektronix 4010 series,

as well as to hard copy and

.SM APL

terminals.)

If there is a code to move the cursor to the left edge of the current row,

give this as

.BR cr .

(Normally this will be carriage-return,

.BR ^M .)

If there is a code to produce an audible signal (bell, beep,

.IR etc.\^ ),

give this as

.BR bl .

.PP

If there is a code (such as backspace)

to move the cursor one position to the left,

that capability should be given as

.BR le .

Similarly,

codes to move to the right, up, and down

should be given as

.BR nd ,

.BR up ,

and

.BR do ,

respectively.

These

.I local cursor motions\^

should not alter the text they pass over;

for example, you would not normally use

\*(lqnd=\ \*(rq

unless the terminal has the

.B os

capability,

because the space would erase the character moved over.

.PP

A very important point here is that the local cursor motions encoded

in

.B termcap\^

have undefined behavior at the left and top edges of a

.SM CRT

display.

Programs should never attempt to backspace around the left edge,

unless

.B bw

is given, and never attempt to go up off the top

using local cursor motions.

.PP

In order to scroll text up,

a program goes to the bottom left corner of the screen and sends the

.B sf

(index) string.

To scroll text down,

a program goes to the top left corner of the screen and sends the

.B sr

(reverse index) string.

The strings

.B sf

and

.B sr

have undefined behavior

when not on their respective corners of the screen.

Parameterized versions of the scrolling sequences are

.B SF

and

.BR SR ,

which have the same semantics as

.B sf

and

.B sr

except that they take one parameter

and scroll that many lines.

They also have undefined behavior

except at the appropriate corner of the screen.

.PP

The

.B am

capability tells whether the cursor sticks at the right

edge of the screen when text is output there,

but this does not necessarily apply to

.B nd

from the last column.

Leftward local motion is defined from the left edge only when

.B bw

is given; then an

.B le

from the left edge will move to the right edge of the previous row.

This is useful for drawing a box around the edge of the screen,

for example.

If the terminal has switch-selectable automatic margins,

the

.B termcap\^

description usually assumes that this feature is on,

.IR i.e. ,

.BR am .

If the terminal has a command

that moves to the first column of the next line,

that command can be given as

.B nw

(newline).

It is permissible for this to clear the remainder of the current line,

so if the terminal has no correctly-working \s-2CR\s0 and \s-2LF\s0

it may still be possible to craft a working

.B nw

out of one or both of them.

.PP

These capabilities suffice to describe hardcopy and \*(lqglass-tty\*(rq terminals.

Thus the Teletype model 33 is described as

.PP

.nf

T3\||\|tty33\||\|33\||\|tty\||\|Teletype model 33:\e

:bl=^G:co#72:cr=^M:do=^J:hc:os:

.fi

.PP

and the Lear Siegler \s-1ADM\s0\-3 is described as

.PP

.nf

l3\||\|adm3\||\|3\||\|LSI \s-1ADM\s0-3:\e

:am:bl=^G:cl=^Z:co#80:cr=^M:do=^J:le=^H:li#24:sf=^J:

.fi

.br

.ne 5

.PP

.B Parameterized Strings

.PP

Cursor addressing and other strings requiring parameters

are described by a

parameterized string capability, with

.BR printf\^ (3)-like

escapes

.B %x

in it,

while other characters are passed through unchanged.

For example, to address the cursor the

.B cm

capability is given, using two parameters: the row and column to move to.

(Rows and columns are numbered from zero and refer to the physical screen

visible to the user, not to any unseen memory.

If the terminal has memory-relative cursor addressing,

that can be indicated by an analogous

.B CM

capability.)

.PP

The

.B %

encodings have the following meanings:

.PP

.in +16n

.ta +8n

.ti -8n

%% output `%'

.ti -8n

%d output value as in \fBprintf\^\fP %d

.ti -8n

%2 output value as in \fBprintf\^\fP %2d

.ti -8n

%3 output value as in \fBprintf\^\fP %3d

.ti -8n

%. output value as in \fBprintf\^\fP %c

.ti -8n

%+\fIx\fP add \fIx\^\fP to value, then do %.

.ti -8n

%>\fIxy\fP if value > \fIx\^\fP then add \fIy\^\fP, no output

.ti -8n

%r reverse order of two parameters, no output

.ti -8n

%i increment by one, no output

.ti -8n

%n exclusive-or all parameters with 0140 (Datamedia 2500)

.ti -8n

%B BCD (16*(value/10)) + (value%10), no output

.ti -8n

%D Reverse coding (value \- 2*(value%16)), no output (Delta Data)

.ti -16n

.fi

.PP

Consider the Hewlett-Packard 2645, which, to get to row 3 and column 12, needs

to be sent \*(lq\eE&a12c03Y\*(rq padded for 6 milliseconds.

Note that the order

of the row and column coordinates is reversed here

and that the row and column

are sent as two-digit integers.

Thus its

.B cm

capability is \*(lqcm=6\eE&%r%2c%2Y\*(rq.

.PP

The Microterm

.SM ACT-IV

needs the current row and column sent

simply encoded in binary

preceded by a

.BR ^T ,

\*(lqcm=^T%.%.\*(rq.

Terminals that use \*(lq%.\*(rq need to be able to

backspace the cursor

.RB ( le )

and to move the cursor up one line on the screen

.RB ( up ).

This is necessary because it is not always safe to transmit

.BR \en ,

.BR ^D ,

and

.BR \er ,

as the system may change or discard them.

(Programs using

.B termcap\^

must set terminal modes so that tabs are not expanded, so

.B \et

is safe to send.

This turns out to be essential for the Ann Arbor 4080.)

.PP

A final example is the Lear Siegler \s-1ADM\s0\-3a,

which offsets row and column

by a blank character, thus \*(lqcm=\eE=%+ %+ \*(rq.

.PP

Row or column absolute cursor addressing

can be given as single parameter capabilities

.B ch

(horizontal position absolute) and

.B cv

(vertical position absolute).

Sometimes these are shorter than the more general two-parameter sequence

(as with the Hewlett-Packard 2645) and can be used in preference to

.BR cm .

If there are parameterized local motions

.RI ( e.g. ,

move

.I n\^

positions to the right)

these can be given as

.BR DO ,

.BR LE ,

.BR RI ,

and

.B UP

with a single parameter indicating how many positions to move.

These are primarily useful if the terminal does not have

.BR cm ,

such as the Tektronix 4025.

.br

.ne 5

.PP

.B Cursor Motions

.PP

If the terminal has a fast way to home the cursor

(to the very upper left corner of the screen), this can be given as

.BR ho .

Similarly, a fast way of getting to the lower left-hand corner

can be given as

.BR ll ;

this may involve going up with

.B up

from the home position,

but a program should never do this itself (unless

.B ll

does), because it can

make no assumption about the effect of moving up from the home position.

Note that the home position is the same as

cursor address (0,0): to the top left corner of the screen, not of memory.

(Therefore, the \*(lq\eEH\*(rq sequence on Hewlett-Packard terminals

cannot be used for

.BR ho .)

.br

.ne 5

.PP

.B Area Clears

.PP

If the terminal can clear from the current position to the end of the

line, leaving the cursor where it is, this should be given as

.BR ce .

If the terminal can clear from the current position to the end of the

display, this should be given as

.BR cd .

.B cd

must only be invoked from the first column of a line.

(Therefore,

it can be simulated by a request to delete a large number of lines,

if a true

.B cd

is not available.)

.br

.ne 5

.PP

.B Insert/Delete Line

.PP

If the terminal can open a new blank line

before the line containing the cursor,

this should be given as

.BR al ;

this must be invoked only from the first

position of a line.

The cursor must then appear at the left of the newly blank line.

If the terminal can delete the line that the cursor is on, this

should be given as

.BR dl ;

this must only be used from the first position on

the line to be deleted.

Versions of

.B al

and

.B dl

which take a single parameter

and insert or delete that many lines

can be given as

.B AL

and

.BR DL .

If the terminal has a settable scrolling region

(like the VT100),

the command to set this can be described with the

.B cs

capability,

which takes two parameters: the top and bottom lines of the scrolling region.

The cursor position is, alas, undefined after using this command.

It is possible to get the effect of insert or delete line

using this command \(em the

.B sc

and