TERM(5) TERM(5)
NAME
term - format of compiled term file.
SYNOPSIS
term
DESCRIPTION
Compiled terminfo descriptions are placed under the directory /usr/share/terminfo. In order to avoid
a linear search of a huge UNIX system directory, a two-level scheme is used: /usr/share/ter-minfo/c/name /usr/share/terminfo/c/name
minfo/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/terminfo/a/act4. Synonyms for the same terminal are imple-mented implemented
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, numbers, strings, and string ta-ble. table.
ble.
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 num-bers numbers
bers 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 termi-nal. terminal.
nal. Note that this format corresponds to the hardware 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, list-ing listing
ing the various names for the terminal, separated by the `|' character. The section is terminated
with an ASCII NUL character.
The boolean flags have one byte for each flag. This byte is either 0 or 1 as the flag is present or
absent. The capabilities are in the same order as the file <term.h>.
Between the boolean section and the number section, a null byte will be inserted, if necessary, to
ensure that the number section begins on an even byte (this is a relic of the PDP-11's word-addressed
architecture, originally designed in to avoid IOT traps induced by addressing a word on an odd byte
boundary). All short integers are aligned on a short word boundary.
The numbers section is similar to the flags section. Each capability takes up two bytes, and is
stored as a little-endian short integer. If the value represented is -1, the 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 representation. Padding information $<nn> and parameter informa-tion information
tion %x are stored intact in uninterpreted form.
The final section is the string table. It contains all the values of string capabilities referenced
in the string section. Each string is null terminated.
Note that it is possible for setupterm to expect a different set of capabilities than are actually
present in the file. Either the database may have been updated since setupterm has been recompiled
(resulting in extra unrecognized entries in the file) or the program may have been recompiled more
recently than the database was updated (resulting in missing entries). The routine setupterm must be
prepared for both possibilities - this is why the numbers and sizes are included. Also, new capabil-ities capabilities
ities must always be added at the end of the lists of boolean, number, and string capabilities.
Despite the consistent use of little-endian for numbers and the otherwise self-describing format, it
is not wise to count on portability of binary terminfo entries between commercial UNIX versions. The
problem is that there are at least three versions of terminfo (under HP-UX, AIX, and OSF/1) which
diverged from System V terminfo after SVr1, and have added extension capabilities to the string table
that (in the binary format) collide with System V and XSI Curses extensions. See terminfo(5) for
detailed discussion of terminfo source compatibility issues.
As an example, here is a hex dump of the description for the Lear-Siegler ADM-3, a popular though
rather stupid early terminal:
adm3a|lsi adm3a,
am,
cols#80, lines#24,
bel=^G, clear= 32$<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 ........ ........
0030 ff ff ff ff ff ff ff ff 0a 00 25 00 27 00 ff ff ........ ..%.'...
0040 29 00 ff ff ff ff 2b 00 ff ff 2d 00 ff ff ff ff ).....+. ..-.....
0050 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0060 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0070 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0080 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0090 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00a0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00b0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00c0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00d0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00e0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00f0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0100 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
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
curses(3X), terminfo(5).
TERM(5)
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