TERM(4) TERM(4)
NAME
term - format of compiled term file.
SYNOPSIS
/usr/lib/terminfo/?/*
DESCRIPTION
Compiled terminfo(4) descriptions are placed under the
directory /usr/lib/terminfo. In order to avoid a linear
search of a huge UNIX system directory, a two-level scheme
is used: /usr/lib/terminfo/c/name where name is the name of
the terminal, and c is the first character of name. Thus,
att4425 can be found in the file
/usr/lib/terminfo/a/att4425. Synonyms for the same terminal
are implemented 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-bit byte is assumed, but no assumptions
about byte ordering or sign extension are made. Thus, these
binary terminfo(4) files can be transported to other
hardware with 8-bit bytes.
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 0377,0377, and the value -2 is
represented by 0376,0377; other negative values are illegal.
Computers where this does not correspond to the hardware
read the integers as two bytes and compute the result,
making the compiled entries portable between machine types.
The -1 generally means that a capability is missing from
this terminal. The -2 means that the capability has been
cancelled in the terminfo(4) source and also is to be
considered missing.
The compiled file is created from the source file
descriptions of the terminals (see the -I option of
infocmp(1M)) by using the terminfo(4) compiler, tic(1M), and
read by the routine setupterm(). (See curses(3X).) The
file is divided into six parts: the header, terminal names,
boolean flags, numbers, 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.
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TERM(4) TERM(4)
The terminal names section comes next. It contains the
first line of the terminfo(4) description, listing the
various names for the terminal, separated by the bar ( | )
character (see term(5)). 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 value
of 2 means that the flag has been cancelled. 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. All short integers
are aligned on a short word boundary.
The numbers section is similar to the boolean flags section.
Each capability takes up two bytes, and is stored as a short
integer. If the value represented is -1 or -2, 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 or -2 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 information (%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 capabilities must
always be added at the end of the lists of boolean, number,
and string capabilities.
Some limitations: total compiled entries cannot exceed 4096
bytes; all entries in the name field cannot exceed 128
bytes.
FILES
/usr/lib/terminfo/?/*compiled terminal description database
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TERM(4) TERM(4)
/usr/include/term.hterminfo(4) header file
SEE ALSO
curses(3X), terminfo(4), term(5).
infocmp(1M) in the System Administrator's Reference Manual.
Chapter 9 of the Programmer's Guide.
ORIGIN
AT&T V.3
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