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terminfo - terminal capability data base  




Terminfo is a data base describing terminals, used by screen-oriented programs such as nvi(1), rogue(1) and libraries such as curses(3X). Terminfo describes terminals by giving a set of capabilities which they have, by specifying how to perform screen operations, and by specifying padding requirements and initialization sequences. This describes ncurses version 5.6 (patch 20061217).

Entries in terminfo consist of a sequence of `,' separated fields (embedded commas may be escaped with a backslash or notated as \054). White space after the `,' separator is ignored. The first entry for each terminal gives the names which are known for the terminal, separated by `|' characters. The first 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 last should be in lower case and contain no blanks; the last name may well contain upper case and blanks for readability.

Lines beginning with a `#' in the first column are treated as comments. While comment lines are legal at any point, the output of captoinfo and infotocap (aliases for tic) will move comments so they occur only between entries.

Newlines and leading tabs may be used for formatting entries for readability. These are removed from parsed entries. The infocmp -f option relies on this to format if-then-else expressions: the result can be read by tic.

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, thus ``hp2621''. This name should not contain hyphens. Modes that the hardware can be in, or user preferences, should be indicated by appending a hyphen and a mode suffix. Thus, a vt100 in 132 column mode would be vt100-w. The following suffixes should be used where possible:

-nnNumber of lines on the screenaaa-60
-npNumber of pages of memoryc100-4p
-amWith automargins (usually the default)vt100-am
-mMono mode; suppress color ansi-m
-mcMagic cookie; spaces when highlightingwy30-mc
-naNo arrow keys (leave them in local)c100-na
-namWithout automatic margins vt100-nam
-nlNo status line att4415-nl
-nsNo status line hp2626-ns
-rvReverse video c100-rv
-sEnable status line vt100-s
-vbUse visible bell instead of beepwy370-vb
-wWide mode (> 80 columns, usually 132)vt100-w

For more on terminal naming conventions, see the term(7) manual page.  


The following is a complete table of the capabilities included in a terminfo description block and available to terminfo-using code. In each line of the table,

The variable is the name by which the programmer (at the terminfo level) accesses the capability.

The capname is the short name used in the text of the database, and is used by a person updating the database. Whenever possible, capnames are chosen to be the same as or similar to the ANSI X3.64-1979 standard (now superseded by ECMA-48, which uses identical or very similar names). Semantics are also intended to match those of the specification.

The termcap code is the old termcap capability name (some capabilities are new, and have names which termcap did not originate). Capability names have no hard length limit, but an informal limit of 5 characters has been adopted to keep them short and to allow the tabs in the source file Caps to line up nicely.

Finally, the description field attempts to convey the semantics of the capability. You may find some codes in the description field:

indicates that padding may be specified
in the description field indicates that the string is passed through tparm with parms as given (#i).
indicates that padding may vary in proportion to the number of lines affected
indicates the ith parameter.

These are the boolean capabilities:

has_print_wheeldaisyYC printer needs operator to change character set
has_status_linehshs has extra status line
hue_lightness_saturationhlshl terminal uses only HLS color notation (Tektronix)

insert mode distinguishes nulls     

YG changing line pitch changes resolution

memory_above dada display may be retained above the screen     



move_standout_modemsgr    ms safe to move while in standout mode

beehive (f1=escape, f2=ctrl C)

npcNP pad character does not exist     




over_strikeos    os terminal can overstrike



only positive motion for vpa/mvpa caps

samYE     printing in last column causes cr     

cannot print ~'s (hazeltine)

transparent_underline    ulul    
underline character overstrikes


These are the numeric capabilities:

magic_cookie_glitchxmcsg number of blank characters left by smso or rmso
max_attributesmama maximum combined attributes terminal can handle
max_colorscolorsCo maximum number of colors on screen

max_pairspairspa     maximum number of color-pairs on the screen

maximum number of defineable windows

no_color_video    ncvNC video attributes that cannot be used with colors     

virtual_terminalvt    vt
virtual terminal number (CB/unix)


The following numeric capabilities are present in the SVr4.0 term structure, but are not yet documented in the man page. They came in with SVr4's printer support.

max_micro_jumpmjumpYe maximum value in parm_..._micro
micro_col_sizemcsYf character step size when in micro mode
micro_line_sizemlsYg line step size when in micro mode

number_of_pinsnpinsYh     numbers of pins in print-head

horizontal resolution in units per line     
output_res_horz_inch    orhiYk
horizontal resolution in units per inch

Yn character step size when in double wide mode

These are the string capabilities:

Set left (right) margin at column #1
set_right_marginsmgrMR set right soft margin at current column
set_right_margin_parmsmgrpZn Set right margin at column #1

set_tabhts    st     set a tab in every row, current columns

Set top margin at current line

Set top (bottom) margin at row #1

Start character set definition #1, with #2 characters in the set

subscript_characterssubcsZu List of subscriptable characters
List of superscriptable characters

these_cause_crdocrZw Printing any of these characters causes CR


to_status_linetslts move to status line, column #1


up_half_linehuhu     half a line up     



user2u2u2     User string #2     



user5u5u5     User string #5


user8u8u8     User string #8




xoff_characterxoffc    XF    
XOFF character
zero_motionzeromZx No motion for subsequent character

The following string capabilities are present in the SVr4.0 term structure, but were originally not documented in the man page.

key_mousekmousKm Mouse event has occurred
mouse_infominfoMi Mouse status information
pc_term_optionspctrmS6 PC terminal options

pkey_plabpfxl    xl     Program function key #1 to type string #2 and show string #3

Request mouse position


scancode_escapescescS7 Escape for scancode emulation     



Shift to codeset 1


set2_des_seq    s2ds    s2     Shift to codeset 2

Shift to codeset 3     

set_a_background    setabAB

Change to ribbon color #1

set_lr_marginsmglrML Set both left and right margins to #1, #2. (ML is not in BSD termcap).




The XSI Curses standard added these. They are some post-4.1 versions of System V curses, e.g., Solaris 2.5 and IRIX 6.x. The ncurses termcap names for them are invented; according to the XSI Curses standard, they have no termcap names. If your compiled terminfo entries use these, they may not be binary-compatible with System V terminfo entries after SVr4.1; beware!

The following entry, describing an ANSI-standard terminal, is representative
of what a terminfo entry for a modern terminal typically looks like.
ansi|ansi/pc-term compatible with color,



        colors#8, ncv#3, pairs#64,

        cub=\E[%p1%dD, cud=\E[%p1%dB, cuf=\E[%p1%dC,    


        cuu=\E[%p1%dA, dch=\E[%p1%dP, dl=\E[%p1%dM,    

        ech=\E[%p1%dX, el1=\E[1K, hpa=\E[%p1%dG, ht=\E[I,

        ich=\E[%p1%d@, il=\E[%p1%dL, indn=\E[%p1%dS, .indn=\E[%p1%dT,    

        kbs=^H, kcbt=\E[Z, kcub1=\E[D, kcud1=\E[B,    

        kcuf1=\E[C, kcuu1=\E[A, kf1=\E[M, kf10=\E[V,

        kf11=\E[W, kf12=\E[X, kf2=\E[N, kf3=\E[O, kf4=\E[P,    

        kf5=\E[Q, kf6=\E[R, kf7=\E[S, kf8=\E[T, kf9=\E[U,    

        kich1=\E[L, mc4=\E[4i, mc5=\E[5i, nel=\r\E[S,

        op=\E[37;40m, rep=%p1%c\E[%p2%{1}%-%db,    

        rin=\E[%p1%dT, s0ds=\E(B, s1ds=\E)B, s2ds=\E*B,    

        s3ds=\E+B, setab=\E[4%p1%dm, setaf=\E[3%p1%dm,




        sgr0=\E[0;10m, tbc=\E[2g, u6=\E[%d;%dR, u7=\E[6n,    

        u8=\E[?%[;0123456789]c, u9=\E[c, vpa=\E[%p1%dd,    
Entries may continue onto multiple lines by placing white space at



Capabilities in





some particular feature, numeric capabilities giving the size of the terminal
or the size of particular delays, and string
capabilities, which give a sequence which can be used to perform particular
terminal operations.
All capabilities have names.
For instance, the fact that
ANSI-standard terminals have
(i.e., an automatic return and line-feed
when the end of a line is reached) is indicated by the capability am.
Hence the description of ansi includes am.
Numeric capabilities are followed by the character `#' and then a positive value.
Thus cols, which indicates the number of columns the terminal has,
gives the value `80' for ansi.
Values for numeric capabilities may be specified in decimal, octal or hexadecimal,
using the C programming language conventions (e.g., 255, 0377 and 0xff or 0xFF).
Finally, string valued capabilities, such as el (clear to end of line
sequence) are given by the two-character code, an `=', and then a string
ending at the next following `,'.
A number of escape sequences are provided in the string valued capabilities
for easy encoding of characters there.
Both \E and \e
map to an ESCAPE character,
^x maps to a control-x for any appropriate x, and the sequences
\n \l \r \t \b \f \s give
a newline, line-feed, return, tab, backspace, form-feed, and space.
Other escapes include \^ for ^,
\\ for \,
\, for comma,
\: for :,
and \0 for null.
(\0 will produce \200, which does not terminate a string but behaves
as a null character on most terminals, providing CS7 is specified.
See stty(1).)
Finally, characters may be given as three octal digits after a \.
A delay in milliseconds may appear anywhere in a string capability, enclosed in
$<..> brackets, as in el=\EK$<5>, and padding characters are supplied by
to provide this delay.
The delay must be a number with at most one decimal
place of precision; it may be followed by suffixes `*' or '/' or both.
A `*'
indicates that the padding required is proportional to the number of lines
affected by the operation, and the amount given is the per-affected-unit
padding required.
(In the case of insert character, the factor is still the
number of
affected.) Normally, padding is advisory if the device has the xon
capability; it is used for cost computation but does not trigger delays.
A `/'
suffix indicates that the padding is mandatory and forces a delay of the given
number of milliseconds even on devices for which xon is present to
indicate flow control.
Sometimes individual capabilities must be commented out.
To do this, put a period before the capability name.
For example, see the second
in the example above.
If the environment variable TERMINFO is set, it is interpreted as the pathname
of a directory containing the compiled description you are working on.
that directory is searched.
If TERMINFO is not set, the ncurses version of the terminfo reader code
will instead look in the directory $HOME/.terminfo
for a compiled description.
If it fails to find one there, and the environment variable TERMINFO_DIRS is
set, it will interpret the contents of that variable as a list of colon-
separated directories to be searched (an empty entry is interpreted as a
command to search /usr/share/terminfo).
If no description is found in any of the
TERMINFO_DIRS directories, the fetch fails.
If neither TERMINFO nor TERMINFO_DIRS is set, the last place tried will be the
system terminfo directory, /usr/share/terminfo.
(Neither the $HOME/.terminfo lookups nor TERMINFO_DIRS extensions are
supported under stock System V terminfo/curses.)
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
and to build up a description gradually, using partial descriptions
or some other screen-oriented program to check that they are correct.
Be aware that a very unusual terminal may expose deficiencies in
the ability of the
file to describe it
or bugs in the screen-handling code of the test program.
To get the padding for insert line right (if the terminal manufacturer
did not document it) a severe test is to edit a large file at 9600 baud,
delete 16 or so lines from the middle of the screen, then hit the `u'
key several times quickly.
If the terminal messes up, more padding is usually needed.
A similar test can be used for insert character.
The number of columns on each line for the terminal is given by the
cols numeric capability.
If the terminal is a CRT, then the
number of lines on the screen is given by the lines capability.
If the terminal wraps around to the beginning of the next line when
it reaches the right margin, then it should have the am capability.
If the terminal can clear its screen, leaving the cursor in the home
position, then this is given by the clear string capability.
If the terminal overstrikes
(rather than clearing a position when a character is struck over)
then it should have the os capability.
If the terminal is a printing terminal, with no soft copy unit,
give it both
applies to storage scope terminals, such as TEKTRONIX 4010
series, as well as 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
(Normally this will be carriage return, control M.)
If there is a code to produce an audible signal (bell, beep, etc)
give this as
If there is a code to move the cursor one position to the left
(such as backspace) that capability should be given as
Similarly, codes to move to the right, up, and down should be
given as
These local cursor motions should not alter the text they pass over,
for example, you would not normally use `cuf1= ' because the
space would erase the character moved over.
A very important point here is that the local cursor motions encoded
are undefined at the left and top edges of a CRT terminal.
Programs should never attempt to backspace around the left edge,
is given,
and never attempt to go up locally off the top.
In order to scroll text up, a program will go to the bottom left corner
of the screen and send the
(index) string.
To scroll text down, a program goes to the top left corner
of the screen and sends the
(reverse index) string.
The strings
are undefined when not on their respective corners of the screen.
Parameterized versions of the scrolling sequences are
which have the same semantics as
except that they take one parameter, and scroll that many lines.
They are also undefined except at the appropriate edge of the screen.
The am capability tells whether the cursor sticks at the right
edge of the screen when text is output, but this does not necessarily
apply to a
from the last column.
The only local motion which is defined from the left edge is if
is given, then a
from the left edge will move to the right edge of the previous row.
is not given, the effect is undefined.
This is useful for drawing a box around the edge of the screen, for example.
If the terminal has switch selectable automatic margins,
file usually assumes that this is on; i.e., am.
If the terminal has a command which moves to the first column of the next
line, that command can be given as
It does not matter if the command clears the remainder of the current line,
so if the terminal has no
it may still be possible to craft a working
out of one or both of them.
These capabilities suffice to describe hard-copy and ``glass-tty'' terminals.
Thus the model 33 teletype is described as
33|tty33|tty|model 33 teletype,
while the Lear Siegler ADM-3 is described as
adm3|3|lsi adm3,
Cursor addressing and other strings requiring parameters
in the terminal are described by a
parameterized string capability, with
like escapes %x in it.
For example, to address the cursor, the
capability is given, using two parameters:
the row and column to address 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
The parameter mechanism uses a stack and special % codes
to manipulate it.
Typically a sequence will push one of the
parameters onto the stack and then print it in some format.
Print (e.g., "%d") is a special case.
Other operations, including "%t" pop their operand from the stack.
It is noted that more complex operations are often necessary,
e.g., in the sgr string.
The % encodings have the following meanings:
outputs `%'
as in printf, flags are [-+#] and space
print pop() like %c in printf
print pop() like %s in printf
push i'th parameter
set dynamic variable [a-z] to pop()
get dynamic variable [a-z] and push it
set static variable [a-z] to pop()
get static variable [a-z] and push it
The terms "static" and "dynamic" are misleading.
Historically, these are simply two different sets of variables,
whose values are not reset between calls to tparm.
However, that fact is not documented in other implementations.
Relying on it will adversely impact portability to other implementations.
char constant c
integer constant nn
push strlen(pop)
%+ %- %* %/ %m
arithmetic (%m is mod): push(pop() op pop())
%& %| %^
bit operations (AND, OR and exclusive-OR): push(pop() op pop())
%= %> %<
logical operations: push(pop() op pop())
%A, %O
logical AND and OR operations (for conditionals)
%! %~
unary operations (logical and bit complement): push(op pop())
add 1 to first two parameters (for ANSI terminals)
%? expr %t thenpart %e elsepart %;
This forms an if-then-else.
The %e elsepart is optional.
Usually the %? expr part pushes a value onto the stack,
and %t pops it from the stack, testing if it is nonzero (true).
If it is zero (false), control passes to the %e (else) part.
It is possible to form else-if's a la Algol 68:
%? c1 %t b1 %e c2 %t b2 %e c3 %t b3 %e c4 %t b4 %e %;
where ci are conditions, bi are bodies.
Use the -f option of tic or infocmp to see
the structure of if-the-else's.
Some strings, e.g., sgr can be very complicated when written
on one line.
The -f option splits the string into lines with the parts indented.
Binary operations are in postfix form with the operands in the usual order.
That is, to get x-5 one would use "%gx%{5}%-".
%P and %g variables are
persistent across escape-string evaluations.
Consider the HP2645, 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 rows and columns is inverted here, and that the row and column
are printed as two digits.
Thus its cup capability is ``cup=6\E&%p2%2dc%p1%2dY''.
The Microterm ACT-IV needs the current row and column sent
preceded by a ^T, with the row and column simply encoded in binary,
Terminals which use ``%c'' need to be able to
backspace the cursor (cub1),
and to move the cursor up one line on the screen (cuu1).
This is necessary because it is not always safe to transmit \n
^D and \r, as the system may change or discard them.
(The library routines dealing with terminfo set tty modes so that
tabs are never expanded, so \t is safe to send.
This turns out to be essential for the Ann Arbor 4080.)
A final example is the LSI ADM-3a, which uses row and column
offset by a blank character, thus ``cup=\E=%p1%' '%+%c%p2%' '%+%c''.
After sending `\E=', this pushes the first parameter, pushes the
ASCII value for a space (32), adds them (pushing the sum on the stack
in place of the two previous values) and outputs that value as a character.
Then the same is done for the second parameter.
More complex arithmetic is possible using the stack.
If the terminal has a fast way to home the cursor
(to very upper left corner of screen) then this can be given as
home; similarly a fast way of getting to the lower left-hand corner
can be given as ll; this may involve going up with cuu1
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 addressing to (0,0):
to the top left corner of the screen, not of memory.
(Thus, the \EH sequence on HP terminals cannot be used for
If the terminal has row or column absolute cursor addressing,
these can be given as single parameter capabilities
(horizontal position absolute)
(vertical position absolute).
Sometimes these are shorter than the more general two parameter
sequence (as with the hp2645) and can be used in preference to
If there are parameterized local motions (e.g., move
spaces to the right) these can be given as
with a single parameter indicating how many spaces to move.
These are primarily useful if the terminal does not have
such as the TEKTRONIX 4025.
If the terminal needs to be in a special mode when running
a program that uses these capabilities,
the codes to enter and exit this mode can be given as smcup and rmcup.
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 one screen-sized window must be fixed into
the terminal for cursor addressing to work properly.
This is also used for the TEKTRONIX 4025,
sets the command character to be the one used by terminfo.
If the smcup sequence will not restore the screen after an
rmcup sequence is output (to the state prior to outputting
rmcup), specify nrrmc.
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 el.
If the terminal can clear from the beginning of the line to the current
position inclusive, leaving
the cursor where it is, this should be given as el1.
If the terminal can clear from the current position to the end of the
display, then this should be given as ed.
Ed is only defined from the first column of a line.
(Thus, it can be simulated by a request to delete a large number of lines,
if a true
is not available.)
If the terminal can open a new blank line before the line where the cursor
is, this should be given as il1; this is done only from the first
position of a line.
The cursor must then appear on the newly blank line.
If the terminal can delete the line which the cursor is on, then this
should be given as dl1; this is done only from the first position on
the line to be deleted.
Versions of
which take a single parameter and insert or delete that many lines can
be given as
If the terminal has a settable scrolling region (like the vt100)
the command to set this can be described with the
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
on a properly chosen region; the
(save and restore cursor) commands may be useful for ensuring that
your synthesized insert/delete string does not move the cursor.
(Note that the ncurses(3X) library does this synthesis
automatically, so you need not compose insert/delete strings for
an entry with csr).
Yet another way to construct insert and delete might be to use a combination of
index with the memory-lock feature found on some terminals (like the HP-700/90
series, which however also has insert/delete).
Inserting lines at the top or bottom of the screen can also be
done using
on many terminals without a true insert/delete line,
and is often faster even on terminals with those features.
The boolean non_dest_scroll_region should be set if each scrolling
window is effectively a view port on a screen-sized canvas.
To test for
this capability, create a scrolling region in the middle of the screen,
write something to the bottom line, move the cursor to the top of the region,
and do ri followed by dl1 or ind.
If the data scrolled
off the bottom of the region by the ri re-appears, then scrolling
is non-destructive.
System V and XSI Curses expect that ind, ri,
indn, and rin will simulate destructive scrolling; their
documentation cautions you not to define csr unless this is true.
This curses implementation is more liberal and will do explicit erases
after scrolling if ndstr is defined.
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
The four parameters are the starting and ending lines in memory
and the starting and ending columns in memory, in that order.
If the terminal can retain display memory above, then the
da capability should be given; if display memory can be retained
below, then db should be given.
These indicate
that deleting a line or scrolling may bring non-blank lines up from below
or that scrolling back with ri may bring down non-blank lines.
There are two basic kinds of intelligent terminals with respect to
insert/delete character which can be described using
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 and 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
If typing characters causes the rest of the line to shift
rigidly and characters to fall off the end, then your terminal does
not distinguish 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, 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 versus multi-line
insert mode, and special treatment of untyped spaces) we have seen no
terminals whose insert mode cannot be described with the single attribute.
Terminfo can describe both terminals which have an insert mode, and terminals
which send a simple sequence to open a blank position on the current line.
Give as smir the sequence to get into insert mode.
Give as rmir the sequence to leave insert mode.
Now give as ich1 any sequence needed to be sent just before sending
the character to be inserted.
Most terminals with a true insert mode
will not give ich1; terminals which send a sequence to open a screen
position should give it here.
If your terminal has both, insert mode is usually preferable to ich1.
Technically, you should not give both unless the terminal actually requires
both to be used in combination.
Accordingly, some non-curses applications get
confused if both are present; the symptom is doubled characters in an update
using insert.
This requirement is now rare; most ich sequences do not
require previous smir, and most smir insert modes do not require ich1
before each character.
Therefore, the new curses actually assumes this
is the case and uses either rmir/smir or ich/ich1 as
appropriate (but not both).
If you have to write an entry to be used under
new curses for a terminal old enough to need both, include the
rmir/smir sequences in ich1.
If post insert padding is needed, give this as a number of milliseconds
in ip (a string option).
Any other sequence which may need to be
sent after an insert of a single character may also be given in ip.
If your terminal needs both to be placed into an `insert mode' and
a special code to precede each inserted character, then both
can be given, and both will be used.
capability, with one parameter,
will repeat the effects of
If padding is necessary between characters typed while not
in insert mode, give this as a number of milliseconds padding in rmp.
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 mir to speed up inserting
in this case.
Omitting mir will affect only speed.
Some terminals
(notably Datamedia's) must not have mir because of the way their
insert mode works.
Finally, you can specify
to delete a single character,
with one parameter,
to delete
and delete mode by giving smdc and rmdc
to enter and exit delete mode (any mode the terminal needs to be placed
in for
to work).
A command to erase
characters (equivalent to outputting
blanks without moving the cursor)
can be given as
with one parameter.
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,
representing 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 smso and rmso, respectively.
If the code to change into or out of standout
mode leaves one or even two blank spaces on the screen,
as the TVI 912 and Teleray 1061 do,
then xmc should be given to tell how many spaces are left.
Codes to begin underlining and end underlining can be given as smul
and rmul respectively.
If the terminal has a code to underline the current character and move
the cursor one space to the right,
such as the Microterm Mime,
this can be given as uc.
Other capabilities to enter various highlighting modes include
(bold or extra bright)
(dim or half-bright)
(blanking or invisible text)
(reverse video)
(turn off
attribute modes)
(enter alternate character set mode)
(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 modes,
this should be given as
(set attributes),
taking 9 parameters.
Each parameter is either 0 or nonzero, as the corresponding attribute is on or off.
The 9 parameters are, in order:
standout, underline, reverse, blink, dim, bold, blank, protect, alternate
character set.
Not all modes need be supported by
only those for which corresponding separate attribute commands exist.
For example, the DEC vt220 supports most of the modes:
l c c
l c c
lw28 lw6 lw2 lw20.
tparm parameter

We begin each escape sequence by turning off any existing modes, since there is no quick way to determine whether they are active. Standout is set up to be the combination of reverse and bold. The vt220 terminal has a protect mode, though it is not commonly used in sgr because it protects characters on the screen from the host's erasures. The altcharset mode also is different in that it is either ^O or ^N, depending on whether it is off or on. If all modes are turned on, the resulting sequence is \E[0;1;4;5;7;8m^N.

Some sequences are common to different modes. For example, ;7 is output when either p1 or p3 is true, that is, if either standout or reverse modes are turned on.

Writing out the above sequences, along with their dependencies yields

Putting this all together into the sgr sequence gives:



Remember that if you specify sgr, you must also specify sgr0.    


Also, some implementations rely on sgr being given if sgr0 is,
Not all terminfo entries necessarily have an sgr string, however.
Many terminfo entries are derived from termcap entries 
which have no sgr string.    
The only drawback to adding an sgr string is that termcap also     
assumes that sgr0 does not exit alternate character set mode.       
Terminals with the ``magic cookie'' glitch        
deposit special ``cookies'' when they receive mode-setting sequences,
each character.    
Some terminals, such as the HP 2621, automatically leave standout
mode when they move to a new line or the cursor is addressed.
Programs using standout mode should exit standout mode before
moving the cursor or sending a newline,
unless the
capability, asserting that it is safe to move in standout mode, is present.
If the terminal has
a way of flashing the screen to indicate an error quietly (a bell replacement)
then this can be given as flash; 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 make, for example, a non-blinking underline into an
easier to find block or blinking underline)
give this sequence as
If there is a way to make the cursor completely invisible, give that as
The capability
should be given which undoes the effects of both of these modes.
If your terminal correctly generates underlined characters
(with no special codes needed)
even though it does not overstrike,
then you should give the capability ul.
If a character overstriking another leaves both characters on the screen,
specify the capability os.
If overstrikes are erasable with a blank,
then this should be indicated by giving eo.
If the terminal has a keypad that transmits codes when the keys are pressed,
this information can be given.
Note that it is not possible to handle
terminals where the keypad only works in local (this applies, for example,
to the unshifted HP 2621 keys).
If the keypad can be set to transmit or not transmit,
give these codes as smkx and rmkx.
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
kcub1, kcuf1, kcuu1, kcud1, and khome respectively.
If there are function keys such as f0, f1, ..., f10, the codes they send
can be given as kf0, kf1, ..., kf10.
If these keys have labels other than the default f0 through f10, the labels
can be given as lf0, lf1, ..., lf10.
The codes transmitted by certain other special keys can be given:
(home down),
(clear all tabs),
(clear the tab stop in this column),
(clear screen or erase key),
(delete character),
(delete line),
(exit insert mode),
(clear to end of line),
(clear to end of screen),
(insert character or enter insert mode),
(insert line),
(next page),
(previous page),
(scroll forward/down),
(scroll backward/up),
(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, the other five keys can be given as
These keys are useful when the effects of a 3 by 3 directional pad are needed.
Strings to program function keys can be given as
A string to program screen labels should be specified as pln.
Each of these strings takes two parameters: the function key number to
program (from 0 to 10) and the string to program it with.
Function key numbers out of this range may program undefined keys in
a terminal dependent manner.
The difference between the capabilities is that
causes pressing the given key to be the same as the user typing the
given string;
causes the string to be executed by the terminal in local; and
causes the string to be transmitted to the computer.
The capabilities nlab, lw and lh
define the number of programmable
screen labels and their width and height.
If there are commands to turn the labels on and off,
give them in smln and rmln.
smln is normally output after one or more pln
sequences to make sure that the change becomes visible.
If the terminal has hardware tabs, the command to advance to the next
tab stop can be given as
(usually control I).
A ``back-tab'' command which moves leftward to the preceding tab stop can
be given as
By convention, if the teletype modes indicate that tabs are being
expanded by the computer rather than being sent to the terminal,
programs should not use
even if they are present, since the user may not have the tab stops
properly set.
If the terminal has hardware tabs which are initially set every
spaces when the terminal is powered up,
the numeric parameter
is given, showing the number of spaces the tabs are set to.
This is normally used by the
command to determine whether to set the mode for hardware tab expansion,
and whether to set the tab stops.
If the terminal has tab stops that can be saved in non-volatile memory,
the terminfo description can assume that they are properly set.
Other capabilities
initialization strings for the terminal,
the path name of a program to be run to initialize 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 terminfo description.
They are normally sent to the terminal, by the
option of the
program, each time the user logs in.
They will be printed in the following order:
run the program
set the margins using
set tabs using
print the file
and finally
Most initialization is done with
Special terminal modes can be set up without duplicating strings
by putting the common sequences in
and special cases in
A set of sequences that does a harder reset from a totally unknown state
can be given as
analogous to
These strings are output by the
program, which is used when the terminal gets into a wedged state.
Commands are normally placed in
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
but it causes an annoying glitch of the screen and is not normally
needed since the terminal is usually already in 80 column mode.
program writes strings
etc., in the same order as the
program, using
etc., instead of
If any of
reset capability strings are missing, the
program falls back upon the corresponding initialization capability string.
If there are commands to set and clear tab stops, they can be given as
(clear all tab stops)
(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
Many older and slower terminals do not support either XON/XOFF or DTR
handshaking, including hard copy terminals and some very archaic CRTs
(including, for example, DEC VT100s).
These may require padding characters
after certain cursor motions and screen changes.
If the terminal uses xon/xoff handshaking for flow control (that is,
it automatically emits ^S back to the host when its input buffers are
close to full), set
This capability suppresses the emission of padding.
You can also set it
for memory-mapped console devices effectively that do not have a speed limit.
Padding information should still be included so that routines can
make better decisions about relative costs, but actual pad characters will
not be transmitted.
If pb (padding baud rate) is given, padding is suppressed at baud rates
below the value of pb.
If the entry has no padding baud rate, then
whether padding is emitted or not is completely controlled by xon.
If the terminal requires other than a null (zero) character as a pad,
then this can be given as pad.
Only the first character of the
string is used.
Some terminals have an extra `status line' which is not normally used by
software (and thus not counted in the terminal's lines capability).
The simplest case is a status line which is cursor-addressable but not
part of the main scrolling region on the screen; the Heathkit H19 has
a status line of this kind, as would a 24-line VT100 with a 23-line
scrolling region set up on initialization.
This situation is indicated
by the hs capability.
Some terminals with status lines need special sequences to access the
status line.
These may be expressed as a string with single parameter
tsl which takes the cursor to a given zero-origin column on the
status line.
The capability fsl must return to the main-screen
cursor positions before the last tsl.
You may need to embed the
string values of sc (save cursor) and rc (restore cursor)
in tsl and fsl to accomplish this.
The status line is normally assumed to be the same width as the width
of the terminal.
If this is untrue, you can specify it with the numeric
capability wsl.
A command to erase or blank the status line may be specified as dsl.
The boolean capability eslok specifies that escape sequences, tabs,
etc., work ordinarily in the status line.
The ncurses implementation does not yet use any of these capabilities.
They are documented here in case they ever become important.
Many terminals have alternate character sets useful for forms-drawing.
Terminfo and curses build in support for the drawing characters
supported by the VT100, with some characters from the AT&T 4410v1 added.
This alternate character set may be specified by the acsc capability.
center expand;
c l l c
c l l c
lw28 lw6 lw2 lw20.
UK pound sign
arrow pointing down
arrow pointing left
arrow pointing right
arrow pointing up
board of squares
checker board (stipple)
degree symbol
greek pi
horizontal line
lantern symbol
large plus or crossover
lower left corner
lower right corner
scan line 1
scan line 3
scan line 7
scan line 9
solid square block
tee pointing down
tee pointing left
tee pointing right
tee pointing up
upper left corner
upper right corner
vertical line

The best way to define a new device's graphics set is to add a column to a copy of this table for your terminal, giving the character which (when emitted between smacs/rmacs switches) will be rendered as the corresponding graphic. Then read off the VT100/your terminal character pairs right to left in sequence; these become the ACSC string.


Color Handling

Most color terminals are either `Tektronix-like' or `HP-like'. Tektronix-like terminals have a predefined set of N colors (where N usually 8), and can set character-cell foreground and background characters independently, mixing them into N * N color-pairs. On HP-like terminals, the use must set each color pair up separately (foreground and background are not independently settable). Up to M color-pairs may be set up from 2*M different colors. ANSI-compatible terminals are Tektronix-like.

Some basic color capabilities are independent of the color method. The numeric capabilities colors and pairs specify the maximum numbers of colors and color-pairs that can be displayed simultaneously. The op (original pair) string resets foreground and background colors to their default values for the terminal. The oc string resets all colors or color-pairs to their default values for the terminal. Some terminals (including many PC terminal emulators) erase screen areas with the current background color rather than the power-up default background; these should have the boolean capability bce.

To change the current foreground or background color on a Tektronix-type terminal, use setaf (set ANSI foreground) and setab (set ANSI background) or setf (set foreground) and setb (set background). These take one parameter, the color number. The SVr4 documentation describes only setaf/setab; the XPG4 draft says that "If the terminal supports ANSI escape sequences to set background and foreground, they should be coded as setaf and setab, respectively. If the terminal supports other escape sequences to set background and foreground, they should be coded as setf and setb, respectively. The vidputs() function and the refresh functions use setaf and setab if they are defined."

The setaf/setab and setf/setb capabilities take a single numeric argument each. Argument values 0-7 of setaf/setab are portably defined as follows (the middle column is the symbolic #define available in the header for the curses or ncurses libraries). The terminal hardware is free to map these as it likes, but the RGB values indicate normal locations in color space.

Color#define ValueRGB
blackCOLOR_BLACK0    0, 0, 0
redCOLOR_RED 1    max,0,0
greenCOLOR_GREEN2    0,max,0
yellowCOLOR_YELLOW3    max,max,0
blueCOLOR_BLUE4    0,0,max
magentaCOLOR_MAGENTA5    max,0,max
cyanCOLOR_CYAN6    0,max,max
whiteCOLOR_WHITE7    max,max,max

The argument values of setf/setb historically correspond to a different mapping, i.e.,

Color#define ValueRGB
blackCOLOR_BLACK0    0, 0, 0
blueCOLOR_BLUE1    0,0,max
greenCOLOR_GREEN2    0,max,0
cyanCOLOR_CYAN3    0,max,max
redCOLOR_RED 4    max,0,0
magentaCOLOR_MAGENTA5    max,0,max
yellowCOLOR_YELLOW6    max,max,0
whiteCOLOR_WHITE7    max,max,max
It is important to not confuse the two sets of color capabilities; otherwise red/blue will be interchanged on the display.

On an HP-like terminal, use scp with a color-pair number parameter to set which color pair is current.

On a Tektronix-like terminal, the capability ccc may be present to indicate that colors can be modified. If so, the initc capability will take a color number (0 to colors - 1)and three more parameters which describe the color. These three parameters default to being interpreted as RGB (Red, Green, Blue) values. If the boolean capability hls is present, they are instead as HLS (Hue, Lightness, Saturation) indices. The ranges are terminal-dependent.

On an HP-like terminal, initp may give a capability for changing a color-pair value. It will take seven parameters; a color-pair number (0 to max_pairs - 1), and two triples describing first background and then foreground colors. These parameters must be (Red, Green, Blue) or (Hue, Lightness, Saturation) depending on hls.

On some color terminals, colors collide with highlights. You can register these collisions with the ncv capability. This is a bit-mask of attributes not to be used when colors are enabled. The correspondence with the attributes understood by curses is as follows:

For example, on many IBM PC consoles, the underline attribute collides with the
foreground color blue and is not available in color mode.
These should have

an ncv capability of 2.

SVr4 curses does nothing with ncv, ncurses recognizes it and optimizes

the output in favor of colors.
If the terminal requires other than a null (zero) character as a pad, then this

can be given as pad.
Only the first character of the pad string is used.
If the terminal does not have a pad character, specify npc.
Note that ncurses implements the termcap-compatible PC variable;

though the application may set this value to something other than

a null, ncurses will test npc first and use napms if the terminal
has no pad character.
If the terminal can move up or down half a line,
this can be indicated with
(half-line up)
(half-line down).
This is primarily useful for superscripts and subscripts on hard-copy terminals.
If a hard-copy terminal can eject to the next page (form feed), give this as
(usually control 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
The first parameter is the character to be repeated and the second
is the number of times to repeat it.
Thus, tparm(repeat_char, 'x', 10) is the same as `xxxxxxxxxx'.
If the terminal has a settable command character, such as the TEKTRONIX 4025,
this can be indicated with
A prototype command character is chosen which is used in all capabilities.
This character is given in the
capability to identify it.
The following convention is supported on some UNIX systems:
The environment is to be searched for a
variable, and if found, all
occurrences of the prototype character are replaced with the character
in the environment variable.
Terminal descriptions that do not represent a specific kind of known
terminal, such as
should include the
(generic) capability so that programs can complain that they do not know
how to talk to the terminal.
(This capability does not apply to
terminal descriptions for which the escape sequences are known.)
If the terminal has a ``meta key'' which acts as a shift key,
setting the 8th bit of any character transmitted, this fact can
be indicated with
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
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
A value of
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 virtual
terminal protocol, the terminal number can be given as
Media copy
strings which control an auxiliary printer connected to the terminal
can be given as
print the contents of the screen,
turn off the printer, and
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
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
is transparently passed to the printer while an
is in effect.
Hazeltine terminals, which do not allow `~' characters to be displayed should
indicate hz.
Terminals which ignore a line-feed immediately after an am wrap,
such as the Concept and vt100,
should indicate xenl.
is required to get rid of standout
(instead of merely writing normal text on top of it),
xhp should be given.
Teleray terminals, where tabs turn all characters moved over to blanks,
should indicate xt (destructive tabs).
Note: the variable indicating this is now `dest_tabs_magic_smso'; in
older versions, it was teleray_glitch.
This glitch is also taken to mean that it is not possible to position
the cursor on top of a ``magic cookie'',
that to erase standout mode it is instead necessary to use
delete and insert line.
The ncurses implementation ignores this glitch.
The Beehive Superbee, which is unable to correctly transmit the escape
or control C characters, has
indicating that the f1 key is used for escape and f2 for control C.
(Only certain Superbees have this problem, depending on the ROM.)
Note that in older terminfo versions, this capability was called
`beehive_glitch'; it is now `no_esc_ctl_c'.
Other specific terminal problems may be corrected by adding more
capabilities of the form xx.
If there are two very similar terminals, one (the variant) can be defined as
being just like the other (the base) with certain exceptions.
In the
definition of the variant, the string capability use can be given with
the name of the base terminal.
The capabilities given before
override those in the base type named by
If there are multiple use capabilities, they are merged in reverse order.
That is, the rightmost use reference is processed first, then the one to
its left, and so forth.
Capabilities given explicitly in the entry override
those brought in by use references.
A capability can be canceled by placing xx@ to the left of the
use reference that imports it, where xx is the capability.
For example, the entry
defines a 2621-nl that does not have the smkx or rmkx capabilities,
and 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.
Long terminfo entries are unlikely to be a problem; to date, no entry has even
approached terminfo's 4096-byte string-table maximum.
Unfortunately, the termcap
translations are much more strictly limited (to 1023 bytes), thus termcap translations
of long terminfo entries can cause problems.
The man pages for 4.3BSD and older versions of tgetent() instruct the user to
allocate a 1024-byte buffer for the termcap entry.
The entry gets null-terminated by
the termcap library, so that makes the maximum safe length for a termcap entry
1k-1 (1023) bytes.
Depending on what the application and the termcap library
being used does, and where in the termcap file the terminal type that tgetent()
is searching for is, several bad things can happen.
Some termcap libraries print a warning message or exit if they find an
entry that's longer than 1023 bytes; others do not; others truncate the
entries to 1023 bytes.
Some application programs allocate more than
the recommended 1K for the termcap entry; others do not.
Each termcap entry has two important sizes associated with it: before
"tc" expansion, and after "tc" expansion.
"tc" is the capability that
tacks on another termcap entry to the end of the current one, to add
on its capabilities.
If a termcap entry does not use the "tc"
capability, then of course the two lengths are the same.
The "before tc expansion" length is the most important one, because it
affects more than just users of that particular terminal.
This is the
length of the entry as it exists in /etc/termcap, minus the
backslash-newline pairs, which tgetent() strips out while reading it.
Some termcap libraries strip off the final newline, too (GNU termcap does not).
Now suppose:
a termcap entry before expansion is more than 1023 bytes long,
and the application has only allocated a 1k buffer,
and the termcap library (like the one in BSD/OS 1.1 and GNU) reads
the whole entry into the buffer, no matter what its length, to see
if it's the entry it wants,
and tgetent() is searching for a terminal type that either is the
long entry, appears in the termcap file after the long entry, or
does not appear in the file at all (so that tgetent() has to search
the whole termcap file).
Then tgetent() will overwrite memory, perhaps its stack, and probably core dump
the program.
Programs like telnet are particularly vulnerable; modern telnets
pass along values like the terminal type automatically.
The results are almost
as undesirable with a termcap library, like SunOS 4.1.3 and Ultrix 4.4, that
prints warning messages when it reads an overly long termcap entry.
If a
termcap library truncates long entries, like OSF/1 3.0, it is immune to dying
here but will return incorrect data for the terminal.
The "after tc expansion" length will have a similar effect to the
above, but only for people who actually set TERM to that terminal
type, since tgetent() only does "tc" expansion once it's found the
terminal type it was looking for, not while searching.
In summary, a termcap entry that is longer than 1023 bytes can cause,
on various combinations of termcap libraries and applications, a core
dump, warnings, or incorrect operation.
If it's too long even before
"tc" expansion, it will have this effect even for users of some other
terminal types and users whose TERM variable does not have a termcap
When in -C (translate to termcap) mode, the ncurses implementation of
tic(1) issues warning messages when the pre-tc length of a termcap
translation is too long.
The -c (check) option also checks resolved (after tc
expansion) lengths.
It is not wise to count on portability of binary terminfo entries between
commercial UNIX versions.
The problem is that there are at least two versions
of terminfo (under HP-UX and AIX) which diverged from System V terminfo after
SVr1, and have added extension capabilities to the string table that (in the
binary format) collide with System V and XSI Curses extensions.
Some SVr4 curses implementations, and all previous to SVr4, do not
interpret the %A and %O operators in parameter strings.
SVr4/XPG4 do not specify whether msgr licenses movement while in
an alternate-character-set mode (such modes may, among other things, map
CR and NL to characters that do not trigger local motions).
The ncurses implementation ignores msgr in ALTCHARSET
This raises the possibility that an XPG4
implementation making the opposite interpretation may need terminfo
entries made for ncurses to have msgr turned off.
The ncurses library handles insert-character and insert-character modes
in a slightly non-standard way to get better update efficiency.
the Insert/Delete Character subsection above.
The parameter substitutions for set_clock and display_clock are
not documented in SVr4 or the XSI Curses standard.
They are deduced from the
documentation for the AT&T 505 terminal.
Be careful assigning the kmous capability.
The ncurses wants to
interpret it as KEY_MOUSE, for use by terminals and emulators like xterm
that can return mouse-tracking information in the keyboard-input stream.
Different commercial ports of terminfo and curses support different subsets of
the XSI Curses standard and (in some cases) different extension sets.
is a summary, accurate as of October 1995:
SVR4, Solaris, ncurses --
These support all SVr4 capabilities.
SGI --
Supports the SVr4 set, adds one undocumented extended string
capability (set_pglen).
SVr1, Ultrix --
These support a restricted subset of terminfo capabilities.
The booleans
end with xon_xoff; the numerics with width_status_line; and the
strings with prtr_non.
HP/UX --
Supports the SVr1 subset, plus the SVr[234] numerics num_labels,
label_height, label_width, plus function keys 11 through 63, plus
plab_norm, label_on, and label_off, plus some incompatible
extensions in the string table.
AIX --
Supports the SVr1 subset, plus function keys 11 through 63, plus a number
of incompatible string table extensions.
OSF --
Supports both the SVr4 set and the AIX extensions.
files containing terminal descriptions
Zeyd M. Ben-Halim, Eric S. Raymond, Thomas E. Dickey.
Based on pcurses by Pavel Curtis.



Color Handling

This document was created by using the manual pages.
Time: 23:07:45 GMT, May 09, 2009