term
SYNOPSIS
term
DESCRIPTION
Compiled terminfo descriptions are placed under the direc
tory /usr/share/terminfo. In order to avoid a linear
search of a huge UNIX system directory, a two-level scheme
is used: /usr/share/terminfo/c/name where name is the name
of the terminal, and c is the first character of name.
Thus, act4 can be found in the file /usr/share/ter
minfo/a/act4. Synonyms for the same terminal are imple
mented by multiple links to the same compiled file.
The format has been chosen so that it will be the same on
all hardware. An 8 or more bit byte is assumed, but no
assumptions about byte ordering or sign extension are
made.
The compiled file is created with the tic program, and
read by the routine setupterm. The file is divided into
six parts: the header, terminal names, boolean flags, num
bers, strings, and string table.
The header section begins the file. This section contains
six short integers in the format described below. These
integers are (1) the magic number (octal 0432); (2) the
size, in bytes, of the names section; (3) the number of
bytes in the boolean section; (4) the number of short
integers in the numbers section; (5) the number of offsets
(short integers) in the strings section; (6) the size, in
bytes, of the string table.
Short integers are stored in two 8-bit bytes. The first
byte contains the least significant 8 bits of the value,
and the second byte contains the most significant 8 bits.
(Thus, the value represented is 256*second+first.) The
value -1 is represented by the two bytes 0377, 0377; other
negative values are illegal. This value generally means
that the corresponding capability is missing from this
terminal. Note that this format corresponds to the hard
ware of the VAX and PDP-11 (that is, little-endian
machines). Machines where this does not correspond to the
hardware must read the integers as two bytes and compute
the little-endian value.
The terminal names section comes next. It contains the
first line of the terminfo description, listing the vari
ous names for the terminal, separated by the `|' charac
ter. The section is terminated with an ASCII NUL charac
ter.
The boolean flags have one byte for each flag. This byte
capability is taken to be missing.
The strings section is also similar. Each capability is
stored as a short integer, in the format above. A value
of -1 means the capability is missing. Otherwise, the
value is taken as an offset from the beginning of the
string table. Special characters in ^X or \c notation are
stored in their interpreted form, not the printing repre
sentation. Padding information $<nn> and parameter infor
mation %x are stored intact in uninterpreted form.
The final section is the string table. It contains all
the values of string capabilities referenced in the string
section. Each string is null terminated.
Note that it is possible for setupterm to expect a differ
ent set of capabilities than are actually present in the
file. Either the database may have been updated since
setupterm has been recompiled (resulting in extra unrecog
nized entries in the file) or the program may have been
recompiled more recently than the database was updated
(resulting in missing entries). The routine setupterm
must be prepared for both possibilities - this is why the
numbers and sizes are included. Also, new capabilities
must always be added at the end of the lists of boolean,
number, and string capabilities.
Despite the consistent use of little-endian for numbers
and the otherwise self-describing format, it is not wise
to count on portability of binary terminfo entries between
commercial UNIX versions. The problem is that there are
at least three versions of terminfo (under HP-UX, AIX, and
OSF/1) which diverged from System V terminfo after SVr1,
and have added extension capabilities to the string table
that (in the binary format) collide with System V and XSI
Curses extensions. See terminfo(5) for detailed discus
sion of terminfo source compatibility issues.
As an example, here is a hex dump of the description for
the Lear-Siegler ADM-3, a popular though rather stupid
early terminal:
adm3a|lsi adm3a,
am,
cols#80, lines#24,
bel=^G, clear= 32$<1>, cr=^M, cub1=^H, cud1=^J,
cuf1=^L, cup=\E=%p1%{32}%+%c%p2%{32}%+%c, cuu1=^K,
home=^^, ind=^J,
0000 1a 01 10 00 02 00 03 00 82 00 31 00 61 64 6d 33 ........ ..1.adm3
0010 61 7c 6c 73 69 20 61 64 6d 33 61 00 00 01 50 00 a|lsi ad m3a...P.
0020 ff ff 18 00 ff ff 00 00 02 00 ff ff ff ff 04 00 ........ ........
0110 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0120 ff ff ff ff ff ff 2f 00 07 00 0d 00 1a 24 3c 31 ....../. .....$<1
0130 3e 00 1b 3d 25 70 31 25 7b 33 32 7d 25 2b 25 63 >..=%p1% {32}%+%c
0140 25 70 32 25 7b 33 32 7d 25 2b 25 63 00 0a 00 1e %p2%{32} %+%c....
0150 00 08 00 0c 00 0b 00 0a 00 ........ .
Some limitations: total compiled entries cannot exceed
4096 bytes. The name field cannot exceed 128 bytes.
FILES
/usr/share/terminfo/*/* compiled terminal capability data
base
SEE ALSO
ncurses(3NCURSES), terminfo(5).
TERM(5)
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