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TERMCAP(5)									       TERMCAP(5)

NAME
       termcap - terminal capability data base

SYNOPSIS
       /etc/termcap

DESCRIPTION
       Termcap	is a data base describing terminals, used, e.g., by vi(1) and curses(3X).  Termi-
       nals are described in 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 termcap.

       Entries in 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.

       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 "hp2621".  This name should not contain hyphens.  Modes that the hard-
       ware can be in or user preferences should be indicated by appending a hyphen and an  indi-
       cator  of the mode.  Therefore, a "vt100" in 132-column mode would be "vt100-w".  The fol-
       lowing suffixes should be used where possible:

       Suffix	Meaning 				  Example
       -w	Wide mode (more than 80 columns)	  vt100-w
       -am	With automatic margins (usually default)  vt100-am
       -nam	Without automatic margins		  vt100-nam
       -n	Number of lines on the screen		  aaa-60
       -na	No arrow keys (leave them in local)	  concept100-na
       -np	Number of pages of memory		  concept100-4p
       -rv	Reverse video				  concept100-rv

CAPABILITIES
       The characters in the Notes field in the table have the following meanings (more than  one
       may apply to a capability):

       N   indicates numeric parameter(s)
       P   indicates that padding may be specified
       *   indicates that padding may be based on the number of lines affected
       o   indicates capability is obsolete

       "Obsolete"  capabilities have no terminfo equivalents, since they were considered useless,
       or are subsumed by other capabilities.  New software should not rely on them at all.

       Name  Type  Notes  Description
       ae    str   (P)	  End alternate character set
       AL    str   (NP*)  Add n new blank lines
       al    str   (P*)   Add new blank line
       am    bool	  Terminal has automatic margins
       as    str   (P)	  Start alternate character set
       bc    str   (o)	  Backspace if not ^H
       bl    str   (P)	  Audible signal (bell)
       bs    bool  (o)	  Terminal can backspace with ^H
       bt    str   (P)	  Back tab
       bw    bool	  le (backspace) wraps from column 0 to last column
       CC    str	  Terminal settable command character in prototype
       cd    str   (P*)   Clear to end of display
       ce    str   (P)	  Clear to end of line
       ch    str   (NP)   Set cursor column (horizontal position)
       cl    str   (P*)   Clear screen and home cursor
       CM    str   (NP)   Memory-relative cursor addressing
       cm    str   (NP)   Screen-relative cursor motion
       co    num	  Number of columns in a line (See BUGS section below)
       cr    str   (P)	  Carriage return
       cs    str   (NP)   Change scrolling region (VT100)
       ct    str   (P)	  Clear all tab stops
       cv    str   (NP)   Set cursor row (vertical position)
       da    bool	  Display may be retained above the screen
       dB    num   (o)	  Milliseconds of bs delay needed (default 0)
       db    bool	  Display may be retained below the screen
       DC    str   (NP*)  Delete n characters
       dC    num   (o)	  Milliseconds of cr delay needed (default 0)
       dc    str   (P*)   Delete character
       dF    num   (o)	  Milliseconds of ff delay needed (default 0)
       DL    str   (NP*)  Delete n lines
       dl    str   (P*)   Delete line
       dm    str	  Enter delete mode
       dN    num   (o)	  Milliseconds of nl delay needed (default 0)
       DO    str   (NP*)  Move cursor down n lines
       do    str	  Down one line
       ds    str	  Disable status line
       dT    num   (o)	  Milliseconds of horizontal tab delay needed (default 0)
       dV    num   (o)	  Milliseconds of vertical tab delay needed (default 0)
       ec    str   (NP)   Erase n characters
       ed    str	  End delete mode
       ei    str	  End insert mode
       eo    bool	  Can erase overstrikes with a blank
       EP    bool  (o)	  Even parity
       es    bool	  Escape can be used on the status line
       ff    str   (P*)   Hardcopy terminal page eject
       fs    str	  Return from status line
       gn    bool	  Generic line type (e.g. dialup, switch)
       hc    bool	  Hardcopy terminal
       HD    bool  (o)	  Half-duplex
       hd    str	  Half-line down (forward 1/2 linefeed)
       ho    str   (P)	  Home cursor
       hs    bool	  Has extra "status line"
       hu    str	  Half-line up (reverse 1/2 linefeed)
       hz    bool	  Cannot print ~s (Hazeltine)
       i1-i3 str	  Terminal initialization strings (terminfo only)
       IC    str   (NP*)  Insert n blank characters
       ic    str   (P*)   Insert character
       if    str	  Name of file containing initialization string
       im    str	  Enter insert mode
       in    bool	  Insert mode distinguishes nulls
       iP    str	  Pathname of program for initialization (terminfo only)
       ip    str   (P*)   Insert pad after character inserted
       is    str	  Terminal initialization string (termcap only)
       it    num	  Tabs initially every n positions
       K1    str	  Sent by keypad upper left
       K2    str	  Sent by keypad upper right
       K3    str	  Sent by keypad center
       K4    str	  Sent by keypad lower left
       K5    str	  Sent by keypad lower right
       k0-k9 str	  Sent by function keys 0-9
       kA    str	  Sent by insert-line key
       ka    str	  Sent by clear-all-tabs key
       kb    str	  Sent by backspace key
       kC    str	  Sent by clear-screen or erase key
       kD    str	  Sent by delete-character key
       kd    str	  Sent by down-arrow key
       kE    str	  Sent by clear-to-end-of-line key
       ke    str	  Out of "keypad transmit" mode
       kF    str	  Sent by scroll-forward/down key
       kH    str	  Sent by home-down key
       kh    str	  Sent by home key
       kI    str	  Sent by insert-character or enter-insert-mode key
       kL    str	  Sent by delete-line key
       kl    str	  Sent by left-arrow key
       kM    str	  Sent by insert key while in insert mode
       km    bool	  Has a "meta" key (shift, sets parity bit)
       kN    str	  Sent by next-page key
       kn    num   (o)	  Number of function (k0-k9) keys (default 0)
       ko    str   (o)	  Termcap entries for other non-function keys
       kP    str	  Sent by previous-page key
       kR    str	  Sent by scroll-backward/up key
       kr    str	  Sent by right-arrow key
       kS    str	  Sent by clear-to-end-of-screen key
       ks    str	  Put terminal in "keypad transmit" mode
       kT    str	  Sent by set-tab key
       kt    str	  Sent by clear-tab key
       ku    str	  Sent by up-arrow key
       l0-l9 str	  Labels on function keys if not "fn"
       LC    bool  (o)	  Lower-case only
       LE    str   (NP)   Move cursor left n positions
       le    str   (P)	  Move cursor left one position
       li    num	  Number of lines on screen or page (See BUGS section below)
       ll    str	  Last line, first column
       lm    num	  Lines of memory if > li (0 means varies)
       ma    str   (o)	  Arrow key map (used by vi version 2 only)
       mb    str	  Turn on blinking attribute
       md    str	  Turn on bold (extra bright) attribute
       me    str	  Turn off all attributes
       mh    str	  Turn on half-bright attribute
       mi    bool	  Safe to move while in insert mode
       mk    str	  Turn on blank attribute (characters invisible)
       ml    str   (o)	  Memory lock on above cursor
       mm    str	  Turn on "meta mode" (8th bit)
       mo    str	  Turn off "meta mode"
       mp    str	  Turn on protected attribute
       mr    str	  Turn on reverse-video attibute
       ms    bool	  Safe to move in standout modes
       mu    str   (o)	  Memory unlock (turn off memory lock)
       nc    bool  (o)	  No correctly-working cr (Datamedia 2500, Hazeltine 2000)
       nd    str	  Non-destructive space (cursor right)
       NL    bool  (o)	  \n is newline, not line feed
       nl    str   (o)	  Newline character if not \n
       ns    bool  (o)	  Terminal is a CRT but doesn't scroll
       nw    str   (P)	  Newline (behaves like cr followed by do)
       OP    bool  (o)	  Odd parity
       os    bool	  Terminal overstrikes
       pb    num	  Lowest baud where delays are required
       pc    str	  Pad character (default NUL)
       pf    str	  Turn off the printer
       pk    str	  Program function key n to type string s (terminfo only)
       pl    str	  Program function key n to execute string s (terminfo only)
       pO    str   (N)	  Turn on the printer for n bytes
       po    str	  Turn on the printer
       ps    str	  Print contents of the screen
       pt    bool  (o)	  Has hardware tabs (may need to be set with is)
       px    str	  Program function key n to transmit string s (terminfo only)
       r1-r3 str	  Reset terminal completely to sane modes (terminfo only)
       rc    str   (P)	  Restore cursor to position of last sc
       rf    str	  Name of file containing reset codes
       RI    str   (NP)   Move cursor right n positions
       rp    str   (NP*)  Repeat character c n times
       rs    str	  Reset terminal completely to sane modes (termcap only)
       sa    str   (NP)   Define the video attributes
       sc    str   (P)	  Save cursor position
       se    str	  End standout mode
       SF    str   (NP*)  Scroll forward n lines
       sf    str   (P)	  Scroll text up
       sg    num	  Number of garbage chars left by so or se (default 0)
       so    str	  Begin standout mode
       SR    str   (NP*)  Scroll backward n lines
       sr    str   (P)	  Scroll text down
       st    str	  Set a tab in all rows, current column
       ta    str   (P)	  Tab to next 8-position hardware tab stop
       tc    str	  Entry of similar terminal - must be last
       te    str	  String to end programs that use termcap
       ti    str	  String to begin programs that use termcap
       ts    str   (N)	  Go to status line, column n
       UC    bool  (o)	  Upper-case only
       uc    str	  Underscore one character and move past it
       ue    str	  End underscore mode
       ug    num	  Number of garbage chars left by us or ue (default 0)
       ul    bool	  Underline character overstrikes
       UP    str   (NP*)  Move cursor up n lines
       up    str	  Upline (cursor up)
       us    str	  Start underscore mode
       vb    str	  Visible bell (must not move cursor)
       ve    str	  Make cursor appear normal (undo vs/vi)
       vi    str	  Make cursor invisible
       vs    str	  Make cursor very visible
       vt    num	  Virtual terminal number (not supported on all systems)
       wi    str   (N)	  Set current window
       ws    num	  Number of columns in status line
       xb    bool	  Beehive (f1=ESC, f2=^C)
       xn    bool	  Newline ignored after 80 cols (Concept)
       xo    bool	  Terminal uses xoff/xon (DC3/DC1) handshaking
       xr    bool  (o)	  Return acts like ce cr nl (Delta Data)
       xs    bool	  Standout not erased by overwriting (Hewlett-Packard)
       xt    bool	  Tabs ruin, magic so char (Teleray 1061)
       xx    bool  (o)	  Tektronix 4025 insert-line

       A Sample Entry

       The following entry, which describes the Concept-100, is among the more complex entries in
       the termcap file as of this writing.

       ca|concept100|c100|concept|c104|concept100-4p|HDS Concept-100:\
	       :al=3*\E^R:am:bl=^G:cd=16*\E^C:ce=16\E^U:cl=2*^L:cm=\Ea%+ %+ :\
	       :co#80:.cr=9^M:db:dc=16\E^A:dl=3*\E^B:do=^J:ei=\E\200:eo:im=\E^P:in:\
	       :ip=16*:is=\EU\Ef\E7\E5\E8\El\ENH\EK\E\200\Eo&\200\Eo\47\E:k1=\E5:\
	       :k2=\E6:k3=\E7:kb=^h:kd=\E<:ke=\Ex:kh=\E?:kl=\E>:kr=\E=:ks=\EX:\
	       :ku=\E;:le=^H:li#24:mb=\EC:me=\EN\200:mh=\EE:mi:mk=\EH:mp=\EI:\
	       :mr=\ED:nd=\E=:pb#9600:rp=0.2*\Er%.%+ :se=\Ed\Ee:sf=^J:so=\EE\ED:\
	       :.ta=8\t:te=\Ev	  \200\200\200\200\200\200\Ep\r\n:\
	       :ti=\EU\Ev  8p\Ep\r:ue=\Eg:ul:up=\E;:us=\EG:\
	       :vb=\Ek\200\200\200\200\200\200\200\200\200\200\200\200\200\200\EK:\
	       :ve=\Ew:vs=\EW:vt#8:xn:\
	       :bs:cr=^M:dC#9:dT#8:nl=^J:ta=^I:pt:

       Entries	may  continue  onto multiple lines by giving a \ 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 "#".

       Types of Capabilities

       Capabilities  in termcap are of three types: Boolean capabilities, which indicate particu-
       lar 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 automatic margins (i.e., an
       automatic return and linefeed when the end of a line is reached) is indicated by the Bool-
       ean capability am.  Hence the description of the Concept includes am.

       Numeric	capabilities  are  followed  by the character `#' then the value.  In the example
       above co, which indicates the number of columns the display has, gives the value `80'  for
       the Concept.

       Finally,  string-valued capabilities, such as 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 char-
       acters to be supplied by tputs after the remainder of the string is sent to  provide  this
       delay.	The  delay  can  be  either a number, e.g.  `20', or a number followed by an `*',
       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  lines
       affected;  this is always 1 unless the terminal has 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.)

       A  number  of  escape  sequences  are  provided in the string-valued capabilities for easy
       encoding of control characters there.  \E maps to an ESC character, ^X maps to a control-X
       for  any  appropriate  X,  and  the sequences \n \r \t \b \f map to linefeed, return, tab,
       backspace, and formfeed, respectively.  Finally, characters may be given  as  three  octal
       digits  after  a \, and the characters ^ and \ may be given as \^ and \\.  If it is neces-
       sary to place a : in a capability it must be escaped in octal as \072.  If it is necessary
       to place a NUL character in a string capability it must be encoded as \200.  (The routines
       that deal with termcap use C strings and strip the high bits of the output very	late,  so
       that a \200 comes out as a \000 would.)

       Sometimes  individual capabilities must be commented out.  To do this, put a period before
       the capability name.  For example, see the first cr and ta in the example above.

       Preparing Descriptions

       We now outline how to prepare descriptions of terminals.  The most effective way  to  pre-
       pare a terminal description is by imitating the description of a similar terminal in term-
       cap and to build up a description gradually, using partial descriptions with vi	to  check
       that  they  are correct.  Be aware that a very unusual terminal may expose deficiencies in
       the ability of the termcap file to describe it or bugs in vi.  To easily test a new termi-
       nal description you can set the environment variable TERMCAP to the absolute pathname of a
       file containing the description you are working on and programs	will  look  there  rather
       than  in /etc/termcap.  TERMCAP can also be set to the termcap entry itself to avoid read-
       ing the file when starting up a program.

       To get the padding for insert-line right (if the terminal manufacturer  did  not  document
       it),  a severe test is to use vi to edit /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-charac-
       ter.

       Basic Capabilities

       The number of columns on each line of the display is given by the co  numeric  capability.
       If  the	display is a CRT, then the number of lines on the screen is given by the li capa-
       bility.	If the display wraps around to the beginning of the next  line	when  the  cursor
       reaches	the  right  margin,  then  it should have the am capability.  If the terminal can
       clear its screen, the code to do this is given by the cl string capability.  If the termi-
       nal  overstrikes  (rather  than clearing the position when a character is overwritten), it
       should have the os capability.  If the terminal is a printing terminal, with no soft  copy
       unit,  give  it	both hc and os.  (os applies to storage scope terminals, such as the Tek-
       tronix 4010 series, as well as to hard copy and APL terminals.)	If there  is  a  code  to
       move the cursor to the left edge of the current row, give this as cr.  (Normally this will
       be carriage-return, ^M.)  If there is a code to produce an  audible  signal  (bell,  beep,
       etc.), give this as bl.

       If  there  is a code (such as backspace) to move the cursor one position to the left, that
       capability should be given as le.  Similarly, codes to move to the  right,  up,	and  down
       should  be  given  as nd, up, and do, respectively.  These local cursor motions should not
       alter the text they pass over; for example, you would not normally use "nd= "  unless  the
       terminal has the os capability, because the space would erase the character moved over.

       A very important point here is that the local cursor motions encoded in termcap have unde-
       fined behavior at the left and top edges of a CRT display.  Programs should never  attempt
       to  backspace around the left edge, unless bw is given, and never attempt to go up off the
       top using local cursor motions.

       In order to scroll text up, a program goes to the bottom left corner  of  the  screen  and
       sends  the  sf (index) string.  To scroll text down, a program goes to the top left corner
       of the screen and sends the sr (reverse index) string.  The strings sf and sr  have  unde-
       fined behavior when not on their respective corners of the screen.  Parameterized versions
       of the scrolling sequences are SF and SR, which have the  same  semantics  as  sf  and  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.

       The 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 nd from the last column.
       Leftward local motion is defined from the left edge only when bw is given; then an 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 termcap description usually assumes that this feature is on, i.e.,
       am.  If the terminal has a command that moves to the first column of the next  line,  that
       command	can  be given as nw (newline).	It is permissible for this to clear the remainder
       of the current line, so if the terminal has no correctly-working CR and LF it may still be
       possible to craft a working nw out of one or both of them.

       These capabilities suffice to describe hardcopy and "glass-tty" terminals.  Thus the Tele-
       type model 33 is described as

	       T3|tty33|33|tty|Teletype model 33:\
		       :bl=^G:co#72:cr=^M:do=^J:hc:os:

       and the Lear Siegler ADM-3 is described as

	       l3|adm3|3|LSI ADM-3:\
		       :am:bl=^G:cl=^Z:co#80:cr=^M:do=^J:le=^H:li#24:sf=^J:

       Parameterized Strings

       Cursor addressing and other strings requiring parameters are described by a  parameterized
       string  capability,  with  printf(3S)-like  escapes  %x	in it, while other characters are
       passed through unchanged.  For example, to address the cursor the 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
       CM capability.)

       The % encodings have the following meanings:

	    %%	 output `%'
	    %d	 output value as in printf %d
	    %2	 output value as in printf %2d
	    %3	 output value as in printf %3d
	    %.	 output value as in printf %c
	    %+x  add x to value, then do %.
	    %>xy if value > x then add y, no output
	    %r	 reverse order of two parameters, no output
	    %i	 increment by one, no output
	    %n	 exclusive-or all parameters with 0140 (Datamedia 2500)
	    %B	 BCD (16*(value/10)) + (value%10), no output
	    %D	 Reverse coding (value - 2*(value%16)), no output (Delta Data)

       Consider the Hewlett-Packard 2645, which, to get to row 3 and column 12, needs to be  sent
       "\E&a12c03Y" padded for 6 milliseconds.	Note that the order of the row and column coordi-
       nates is reversed here and that the row and column are sent as two-digit  integers.   Thus
       its cm capability is "cm=6\E&%r%2c%2Y".

       The  Microterm  ACT-IV needs the current row and column sent simply encoded in binary pre-
       ceded by a ^T, "cm=^T%.%.".  Terminals that use "%." need to be able to backspace the cur-
       sor (le) and to move the cursor up one line on the screen (up).	This is necessary because
       it is not always safe to transmit \n, ^D, and \r, as the  system  may  change  or  discard
       them.   (Programs  using termcap must set terminal modes so that tabs are not expanded, so
       \t is safe to send.  This turns out to be essential for the Ann Arbor 4080.)

       A final example is the Lear Siegler ADM-3a, which offsets row and column by a blank  char-
       acter, thus "cm=\E=%+ %+ ".

       Row  or column absolute cursor addressing can be given as single parameter capabilities ch
       (horizontal position absolute) and 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 cm.  If there are parameterized local motions (e.g., move
       n positions to the right) these can be given as DO, LE, RI, and UP with a single parameter
       indicating how many positions to move.  These are primarily useful if  the  terminal  does
       not have cm, such as the Tektronix 4025.

       Cursor Motions

       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 ho.  Similarly, a fast way of getting to the lower left-hand
       corner can be given as ll; this may involve going up with up from the home position, but a
       program should never do this itself (unless 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 "\EH" sequence on Hewlett-Packard terminals cannot be used for ho.)

       Area Clears

       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 ce.	If the terminal can clear from	the  cur-
       rent  position  to  the	end  of the display, this should be given as cd.  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 cd is not available.)

       Insert/Delete Line

       If  the	terminal  can  open  a new blank line before the line containing the cursor, this
       should be given as 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 dl; this must only  be  used  from
       the  first  position on the line to be deleted.	Versions of al and dl which take a single
       parameter and insert or delete that many lines can be given as AL and DL.  If the terminal
       has a settable scrolling region (like the VT100), the command to set this can be described
       with the 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 -- the sc and rc
       (save  and restore cursor) commands are also useful.  Inserting lines at the top or bottom
       of the screen can also  be  done  using	sr  or	sf  on	many  terminals  without  a  true
       insert/delete line, and is often faster even on terminals with those features.

       If  the	terminal  has the ability to define a window as part of memory which all commands
       affect, it should be given as the parameterized string wi.  The four  parameters  are  the
       starting and ending lines in memory and the starting and ending columns in memory, in that
       order.  (This terminfo capability is described for completeness.  It is unlikely that  any
       termcap-using program will support it.)

       If  the terminal can retain display memory above the screen, then the da capability should
       be given; if display memory can be retained below, then db should be given.   These  indi-
       cate  that  deleting  a	line or scrolling may bring non-blank lines up from below or that
       scrolling back with sr may bring down non-blank lines.

       Insert/Delete Character

       There are two basic kinds of intelligent terminals with respect to insert/delete character
       that  can  be described using termcap.  The most common insert/delete character operations
       affect only the characters on the current line and shift characters off	the  end  of  the
       line  rigidly.	Other terminals, such as the Concept-100 and the Perkin Elmer Owl, make a
       distinction between typed and untyped blanks on the screen, shifting  upon  an  insert  or
       delete  only  to  an untyped blank on the screen which is either eliminated or expanded to
       two untyped blanks.  You can determine the kind of  terminal  you  have	by  clearing  the
       screen then typing text separated by cursor motions.  Type "abc	  def" using local cursor
       motions (not spaces) between the "abc" and the "def".  Then position the cursor before the
       "abc"  and  put	the terminal in insert mode.  If typing characters causes the rest of the
       line to shift rigidly and characters to fall off the end, then your terminal does not dis-
       tinguish  between  blanks  and  untyped	positions.  If the "abc" shifts over to the "def"
       which then move together around the end of the current line  and  onto  the  next  as  you
       insert, then you have the second type of terminal and should give the capability in, which
       stands for "insert null".  While these are two logically separate attributes (one line vs.
       multi-line  insert  mode, and special treatment of untyped spaces), we have seen no termi-
       nals whose insert mode cannot be described with the single attribute.

       Termcap can describe both terminals that have an insert mode and  terminals  that  send	a
       simple  sequence to open a blank position on the current line.  Give as im the sequence to
       get into insert mode.  Give as ei the sequence to leave insert mode.  Now give as  ic  any
       sequence  that needs to be sent just before each character to be inserted.  Most terminals
       with a true insert mode will not give ic; terminals that use a sequence to open	a  screen
       position  should give it here.  (If your terminal has both, insert mode is usually prefer-
       able to ic.  Do not give both unless the terminal actually requires both  to  be  used  in
       combination.)   If post-insert padding is needed, give this as a number of milliseconds in
       ip (a string option).  Any other sequence that may need to be sent after  insertion  of	a
       single  character  can  also  be given in ip.  If your terminal needs to be placed into an
       `insert mode' and needs a special code preceding each inserted character, then both  im/ei
       and ic can be given, and both will be used.  The IC capability, with one parameter n, will
       repeat the effects of ic n times.

       It is occasionally necessary to move around while in insert mode to delete  characters  on
       the  same  line	(e.g., if there is a tab after the insertion position).  If your terminal
       allows motion while in insert mode, you can give the capability mi to speed  up	inserting
       in  this  case.	Omitting mi will affect only speed.  Some terminals (notably Datamedia's)
       must not have mi because of the way their insert mode works.

       Finally, you can specify dc to delete a single character,  DC  with  one  parameter  n  to
       delete  n  characters,  and  delete mode by giving dm and ed to enter and exit delete mode
       (which is any mode the terminal needs to be placed in for dc to work).

       Highlighting, Underlining, and Visible Bells

       If your terminal has one or more kinds of display attributes, these can be represented  in
       a  number  of different ways.  You should choose one display form as standout mode, repre-
       senting a good high-contrast, easy-on-the-eyes format for highlighting error messages  and
       other  attention  getters.  (If you have a choice, reverse video plus half-bright is good,
       or reverse video alone.)  The sequences to enter and exit standout mode are  given  as  so
       and  se,  respectively.	 If the code to change into or out of standout mode leaves one or
       even two blank spaces or garbage characters on the screen, as the TVI 912 and Teleray 1061
       do, then sg should be given to tell how many characters are left.

       Codes  to  begin  underlining and end underlining can be given as us and ue, respectively.
       Underline mode change garbage is specified by ug, similar to sg.  If the  terminal  has	a
       code  to  underline  the  current character and move the cursor one position to the right,
       such as the Microterm Mime, this can be given as uc.

       Other capabilities to enter various highlighting modes include mb (blinking), md (bold  or
       extra  bright),	mh (dim or half-bright), mk (blanking or invisible text), mp (protected),
       mr (reverse video), me (turn off all attribute modes), as (enter alternate  character  set
       mode),  and  ae (exit alternate character set mode).  Turning on any of these modes singly
       may or may not turn off other modes.

       If there is a sequence to set arbitrary combinations of mode, this should be given  as  sa
       (set  attributes),  taking  9  parameters.  Each parameter is either 0 or 1, as the corre-
       sponding attributes is on or off.  The 9 parameters are, in  order:  standout,  underline,
       reverse,  blink,  dim,  bold,  blank, protect, and alternate character set.  Not all modes
       need be supported by sa, only those for which corresponding attribute commands exist.  (It
       is  unlikely  that  a termcap-using program will support this capability, which is defined
       for compatibility with terminfo.)

       Terminals with the "magic cookie" glitches (sg and  ug),  rather  than  maintaining  extra
       attribute  bits	for  each  character cell, instead deposit special "cookies", or "garbage
       characters", when they receive mode-setting sequences, which affect the display algorithm.

       Some terminals, such as the Hewlett-Packard 2621, automatically leave standout  mode  when
       they  move  to  a  new line or when the cursor is addressed.  Programs using standout mode
       should exit standout mode on such terminals before moving the cursor or sending a newline.
       On  terminals where this is not a problem, the ms capability should be present to say that
       this overhead is unnecessary.

       If the terminal has a way of flashing the screen to indicate  an  error	quietly  (a  bell
       replacement), this can be given as vb; it must not move the cursor.

       If  the cursor needs to be made more visible than normal when it is not on the bottom line
       (to change, for example, a non-blinking underline into an easier-to-find block or blinking
       underline),  give  this	sequence  as vs.  If there is a way to make the cursor completely
       invisible, give that as vi.  The capability ve, which undoes the effects of both of  these
       modes, should also be given.

       If  your  terminal correctly displays underlined characters (with no special codes needed)
       even though it does not overstrike, then you should give  the  capability  ul.	If  over-
       strikes are erasable with a blank, this should be indicated by giving eo.

       Keypad

       If the terminal has a keypad that transmits codes when the keys are pressed, this informa-
       tion can be given.  Note that it is not possible to handle terminals where the keypad only
       works  in  local  mode  (this  applies, for example, to the unshifted Hewlett-Packard 2621
       keys).  If the keypad can be set to transmit or not transmit, give these codes as  ks  and
       ke.   Otherwise	the  keypad  is  assumed to always transmit.  The codes sent by the left-
       arrow, right-arrow, up-arrow, down-arrow, and home keys can be given as kl,  kr,  ku,  kd,
       and  kh, respectively.  If there are function keys such as f0, f1, ..., f9, the codes they
       send can be given as k0, k1,..., k9.  If these keys have labels other than the default  f0
       through	f9,  the labels can be given as l0, l1,..., l9.  The codes transmitted by certain
       other special keys can be given: kH (home down), kb (backspace), ka (clear all  tabs),  kt
       (clear the tab stop in this column), kC (clear screen or erase), kD (delete character), kL
       (delete line), kM (exit insert mode), kE (clear to end of  line),  kS  (clear  to  end  of
       screen),  kI (insert character or enter insert mode), kA (insert line), kN (next page), kP
       (previous page), kF (scroll forward/down), kR (scroll backward/up), and kT (set a tab stop
       in this column).  In addition, if the keypad has a 3 by 3 array of keys including the four
       arrow keys, then the other five keys can be given as K1, K2, K3, K4, and K5.   These  keys
       are useful when the effects of a 3 by 3 directional pad are needed.  The obsolete ko capa-
       bility formerly used to describe "other" function keys has been completely  supplanted  by
       the above capabilities.

       The  ma	entry is also used to indicate arrow keys on terminals that have single-character
       arrow keys.  It is obsolete but still in use in version 2 of vi which must be run on  some
       minicomputers due to memory limitations.  This field is redundant with kl, kr, ku, kd, and
       kh.  It consists of groups of two characters.  In each group, the first character is  what
       an  arrow key sends, and the second character is the corresponding vi command.  These com-
       mands are h for kl, j for kd, k for ku, l for kr, and H for kh.	 For  example,	the  Mime
       would  have  "ma=^Hh^Kj^Zk^Xl"  indicating  arrow  keys left (^H), down (^K), up (^Z), and
       right (^X).  (There is no home key on the Mime.)

       Tabs and Initialization

       If the terminal needs to be in a special mode when running a program that uses these capa-
       bilities,  the  codes to enter and exit this mode can be given as ti and te.  This arises,
       for example, from terminals like the Concept with more than one page of	memory.   If  the
       terminal  has  only  memory-relative  cursor  addressing  and  not  screen-relative cursor
       addressing, a screen-sized window must be fixed into the display for cursor addressing  to
       work  properly.	This is also used for the Tektronix 4025, where ti sets the command char-
       acter to be the one used by termcap.

       Other capabilities include is, an initialization string for the terminal, and if, the name
       of  a  file containing long initialization strings.  These strings are expected to set the
       terminal into modes consistent with the rest of the termcap description.   They	are  nor-
       mally  sent  to the terminal by the tset program each time the user logs in.  They will be
       printed in the following order: is; setting tabs using ct and st; and finally  if.   (Ter-
       minfo  uses i1-i2 instead of is and runs the program iP and prints i3 after the other ini-
       tializations.)  A pair of sequences that does a harder reset from a totally unknown  state
       can  be	analogously  given  as rs and if.  These strings are output by the reset program,
       which is used when the terminal gets into a wedged state.  (Terminfo uses r1-r3 instead of
       rs.)   Commands	are normally placed in rs and rf only if they produce annoying effects on
       the screen and are not necessary when logging in.  For example, the  command  to  set  the
       VT100  into  80-column mode would normally be part of is, but it causes an annoying glitch
       of the screen and is not normally needed since the terminal is usually already in  80-col-
       umn mode.

       If  the	terminal  has  hardware  tabs, the command to advance to the next tab stop can be
       given as ta (usually ^I).  A "backtab" command which moves leftward to  the  previous  tab
       stop  can  be  given as bt.  By convention, if the terminal driver modes indicate that tab
       stops are being expanded by the computer rather than being sent to the terminal,  programs
       should  not  use  ta  or  bt even if they are present, since the user may not have the tab
       stops properly set.  If the terminal has hardware tabs that  are  initially  set  every	n
       positions when the terminal is powered up, then the numeric parameter it is given, showing
       the number of positions between tab stops.  This is normally used by the tset  command  to
       determine  whether  to  set the driver mode for hardware tab expansion, and whether to set
       the tab stops.  If the terminal has tab stops that can be saved in nonvolatile memory, the
       termcap description can assume that they are properly set.

       If  there  are commands to set and clear tab stops, they can be given as ct (clear all tab
       stops) and st (set a tab stop in the current column of every  row).   If  a  more  complex
       sequence  is  needed  to  set  the tabs than can be described by this, the sequence can be
       placed in is or if.

       Delays

       Certain capabilities control padding in the terminal driver.  These are	primarily  needed
       by hardcopy terminals and are used by the tset program to set terminal driver modes appro-
       priately.  Delays embedded in the capabilities cr, sf, le,  ff,	and  ta  will  cause  the
       appropriate  delay  bits  to  be set in the terminal driver.  If pb (padding baud rate) is
       given, these values can be ignored at baud rates below the value of pb.	For 4.2BSD  tset,
       the delays are given as numeric capabilities dC, dN, dB, dF, and dT instead.

       Miscellaneous

       If  the terminal requires other than a NUL (zero) character as a pad, this can be given as
       pc.  Only the first character of the pc string is used.

       If the terminal has commands to save and restore the position of the cursor, give them  as
       sc and rc.

       If  the	terminal  has  an extra "status line" that is not normally used by software, this
       fact can be indicated.  If the status line is viewed as an extra  line  below  the  bottom
       line,  then the capability hs should be given.  Special strings to go to a position in the
       status line and to return from the status line can be given as ts and fs.  (fs must  leave
       the  cursor position in the same place that it was before ts.  If necessary, the sc and rc
       strings can be included in ts and fs to get this effect.)  The  capability  ts  takes  one
       parameter,  which  is  the  column  number of the status line to which the cursor is to be
       moved.  If escape sequences and other special commands such as tab work while in the  sta-
       tus line, the flag es can be given.  A string that turns off the status line (or otherwise
       erases its contents) should be given as ds.  The status line is normally assumed to be the
       same  width  as the rest of the screen, i.e., co.  If the status line is a different width
       (possibly because the terminal does not allow an entire line to be loaded), then its width
       in columns can be indicated with the numeric parameter ws.

       If  the terminal can move up or down half a line, this can be indicated with hu (half-line
       up) and hd (half-line down).  This is primarily useful for superscripts and subscripts  on
       hardcopy  terminals.   If a hardcopy terminal can eject to the next page (form feed), give
       this as ff (usually ^L).

       If there is a command to repeat a given character a given number of times  (to  save  time
       transmitting  a	large  number  of  identical  characters), this can be indicated with the
       parameterized string rp.  The first parameter is the character to be repeated and the sec-
       ond  is the number of times to repeat it.  (This is a terminfo feature that is unlikely to
       be supported by a program that uses termcap.)

       If the terminal has a settable command character, such as the Tektronix 4025, this can  be
       indicated with CC.  A prototype command character is chosen which is used in all capabili-
       ties.  This character is given in the CC capability to identify it.  The following conven-
       tion  is  supported on some UNIX systems: The environment is to be searched for a CC vari-
       able, and if found, all occurrences of the prototype character are replaced by the charac-
       ter  in	the  environment variable.  This use of the CC environment variable is a very bad
       idea, as it conflicts with make(1).

       Terminal descriptions that do not represent a specific kind of  known  terminal,  such  as
       switch,	dialup,  patch,  and  network, should include the gn (generic) capability so that
       programs can complain that they do not know how to talk to the terminal.  (This capability
       does not apply to virtual terminal descriptions for which the escape sequences are known.)

       If  the	terminal  uses xoff/xon (DC3/DC1) handshaking for flow control, give xo.  Padding
       information should still be included so that routines  can  make  better  decisions  about
       costs, but actual pad characters will not be transmitted.

       If  the	terminal  has  a "meta key" which acts as a shift key, setting the 8th bit of any
       character transmitted, then this fact can be indicated with km.	Otherwise, software  will
       assume  that  the  8th  bit is parity and it will usually be cleared.  If strings exist to
       turn this "meta mode" on and off, they can be given as mm and mo.

       If the terminal has more lines of memory than will fit on the screen at once,  the  number
       of  lines  of  memory can be indicated with lm.	An explicit value of 0 indicates that the
       number of lines is not fixed, but that there is still more memory than fits on the screen.

       If the terminal is one of those supported by the UNIX system  virtual  terminal	protocol,
       the terminal number can be given as vt.

       Media  copy  strings  which  control an auxiliary printer connected to the terminal can be
       given as ps: print the contents of the screen; pf: turn off the printer; and po:  turn  on
       the  printer.   When  the printer is on, all text sent to the terminal will be sent to the
       printer.  It is undefined whether the text is also displayed on the terminal  screen  when
       the  printer  is  on.  A variation pO takes one parameter and leaves the printer on for as
       many characters as the value of the parameter, then turns the printer off.  The	parameter
       should  not  exceed  255.   All text, including pf, is transparently passed to the printer
       while pO is in effect.

       Strings to program function keys can be given as pk, pl, and px.  Each  of  these  strings
       takes  two  parameters: the function key number to program (from 0 to 9) and the string to
       program it with.  Function key numbers out of this range may program undefined keys  in	a
       terminal-dependent  manner.   The  differences  among  the capabilities are that pk causes
       pressing the given key to be the same as the user typing the given string; pl  causes  the
       string to be executed by the terminal in local mode; and px causes the string to be trans-
       mitted to the computer.	Unfortunately, due to lack of a definition for string  parameters
       in termcap, only terminfo supports these capabilities.

       Glitches and Braindamage

       Hazeltine  terminals,  which  do not allow `~' characters to be displayed, should indicate
       hz.

       The nc capability, now obsolete, formerly indicated Datamedia terminals, which echo \r  \n
       for carriage return then ignore a following linefeed.

       Terminals that ignore a linefeed immediately after an am wrap, such as the Concept, should
       indicate xn.

       If ce is required to get rid of standout (instead of merely writing normal text on top  of
       it), xs should be given.

       Teleray terminals, where tabs turn all characters moved over to blanks, should indicate xt
       (destructive tabs).  This glitch is also taken to mean that it is not possible to position
       the  cursor on top of a "magic cookie", and that to erase standout mode it is necessary to
       use delete and insert line.

       The Beehive Superbee, which is unable to correctly transmit the ESC or ^C characters,  has
       xb, indicating that the "f1" key is used for ESC and "f2" for ^C.  (Only certain Superbees
       have this problem, depending on the ROM.)

       Other specific terminal problems may be corrected by adding more capabilities of the  form
       xx.

       Similar Terminals

       If  there  are two very similar terminals, one can be defined as being just like the other
       with certain exceptions.  The string capability tc can be given with the name of the simi-
       lar  terminal.	This capability must be last, and the combined length of the entries must
       not exceed 1024.  The capabilities given before tc override those  in  the  terminal  type
       invoked	by tc.	A capability can be canceled by placing xx@ to the left of the tc invoca-
       tion, where xx is the capability.  For example, the entry

	    hn|2621-nl:ks@:ke@:tc=2621:

       defines a "2621-nl" that does not have the ks or ke capabilities, hence does not  turn  on
       the  function  key  labels  when in visual mode.  This is useful for different modes for a
       terminal, or for different user preferences.

AUTHOR
       William Joy
       Mark Horton added underlining and keypad support

FILES
       /etc/termcap   file containing terminal descriptions

SEE ALSO
       ex(1), more(1), tset(1), ul(1), vi(1), curses(3X), printf(3S), term(7).

CAVEATS AND BUGS
       Note: termcap was replaced by terminfo in UNIX System V Release 2.0.  The transition  will
       be relatively painless if capabilities flagged as "obsolete" are avoided.

       Lines and columns are now stored by the kernel as well as in the termcap entry.	Most pro-
       grams now use the kernel information primarily; the information in this file is used  only
       if the kernel does not have any information.

       Vi  allows  only 256 characters for string capabilities, and the routines in termlib(3) do
       not check for overflow of this buffer.  The total length of a single entry (excluding only
       escaped newlines) may not exceed 1024.

       Not all programs support all entries.

3rd Berkeley Distribution		 1 November 1985			       TERMCAP(5)
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