'\" t
.\"***************************************************************************
-.\" Copyright 2018-2021,2023 Thomas E. Dickey *
+.\" Copyright 2018-2023,2024 Thomas E. Dickey *
.\" Copyright 1998-2016,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: term.5,v 1.65 2023/11/25 22:58:12 tom Exp $
-.TH term 5 2023-11-25 "ncurses 6.4" "File formats"
+.\" $Id: term.5,v 1.77 2024/04/20 21:24:19 tom Exp $
+.TH term 5 2024-04-20 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "File formats"
.ie \n(.g \{\
.ds `` \(lq
.ds '' \(rq
.SH SYNOPSIS
.B term
.SH DESCRIPTION
-.SS STORAGE LOCATION
+.SS "Storage Location"
Compiled terminfo descriptions are placed under the directory \fB\*d\fP.
-Two configurations are supported (when building the \fBncurses\fP libraries):
+Two configurations are supported
+(when building the \fI\%ncurses\fP libraries):
.TP 5
.B directory tree
A two-level scheme is used to avoid a linear search
and records containing only aliases pointing to the primary name.
.IP
If built to write hashed databases,
-\fBncurses\fP can still read terminfo databases organized as a directory tree,
+\fI\%ncurses\fP can still read terminfo databases organized as a
+directory tree,
but cannot write entries into the directory tree.
It can write (or rewrite) entries in the hashed database.
.IP
-\fBncurses\fP distinguishes the two cases in the TERMINFO and TERMINFO_DIRS
-environment variable by assuming a directory tree for entries that
-correspond to an existing directory,
+\fI\%ncurses\fP distinguishes the two cases in the \fI\%TERMINFO\fP and
+\fI\%TERMINFO_DIRS\fP environment variable by assuming a directory tree
+for entries that correspond to an existing directory,
and hashed database otherwise.
-.SS LEGACY STORAGE FORMAT
+.SS "Legacy Storage Format"
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.
.TP 3
b) \fIterminal names\fP,
.TP 3
-c) \fIboolean flags\fP,
+c) \fIBoolean flags\fP,
.TP 3
d) \fInumbers\fP,
.TP 3
.TP 5
(2) the size, in bytes, of the \fIterminal names\fP section;
.TP 5
-(3) the number of bytes in the \fIboolean flags\fP section;
+(3) the number of bytes in the \fIBoolean flags\fP section;
.TP 5
(4) the number of short integers in the \fInumbers\fP section;
.TP 5
.RE
.PP
The capabilities in the
-\fIboolean flags\fP,
+\fIBoolean flags\fP,
\fInumbers\fP, and
\fIstrings\fP
sections are in the same order as the file <term.h>.
.IP
The integer value \-1 is represented by two bytes 0377, 0377.
.br
-Absent boolean values are represented by the byte 0 (false).
+Absent Boolean values are represented by the byte 0 (false).
.bP
If a capability has been canceled from this terminal,
@TIC@ stores a \-2 in the corresponding table.
.IP
The integer value \-2 is represented by two bytes 0377, 0376.
.br
-The boolean value \-2 is represented by the byte 0376.
+The Boolean value \-2 is represented by the byte 0376.
.br
.bP
Other negative values are illegal.
The \fIterminal names\fP section is terminated
with an \s-1ASCII NUL\s+1 character.
.PP
-The \fIboolean flags\fP section has one byte for each flag.
+The \fIBoolean flags\fP section has one byte for each flag.
Boolean capabilities are either 1 or 0 (true or false)
according to whether the terminal supports the given capability or not.
.PP
-Between the \fIboolean flags\fP section and the \fInumber\fP section,
+Between the \fIBoolean flags\fP section and the \fInumber\fP section,
a null byte will be inserted, if necessary,
to ensure that the \fInumber\fP section begins on an even byte
This is a relic of the PDP\-11's word-addressed architecture,
by addressing a word on an odd byte boundary.
All short integers are aligned on a short word boundary.
.PP
-The \fInumbers\fP section is similar to the \fIboolean flags\fP section.
+The \fInumbers\fP section is similar to the \fIBoolean flags\fP section.
Each capability takes up two bytes,
and is stored as a little-endian short integer.
.PP
interpreted form, not the printing representation.
Padding information $<nn> and parameter information %x are
stored intact in uninterpreted form.
-.SS EXTENDED STORAGE FORMAT
+.SS "Extended Storage Format"
The previous section describes the conventional terminfo binary format.
With some minor variations of the offsets (see PORTABILITY),
the same binary format is used in all modern Unix systems.
-Each system uses a predefined set of boolean, number or string capabilities.
+Each system uses a predefined set of Boolean, number or string capabilities.
.PP
-The \fBncurses\fP libraries and applications support
+The \fI\%ncurses\fP libraries and applications support
extended terminfo binary format,
allowing users to define capabilities which are loaded at runtime.
This
extension is made possible by using the fact that the other implementations
stop reading the terminfo data when they have reached the end of the size given
in the header.
-\fBncurses\fP checks the size,
+\fI\%ncurses\fP checks the size,
and if it exceeds that due to the predefined data,
continues to parse according to its own scheme.
.PP
.RS 5
.TP 5
(1)
-count of extended boolean capabilities
+count of extended Boolean capabilities
.TP 5
(2)
count of extended numeric capabilities
include the extended capability \fInames\fP as well as
extended capability \fIvalues\fP.
.PP
-Using the counts and sizes, \fBncurses\fP allocates arrays and reads data
-for the extended capabilities in the same order as the header information.
+Using the counts and sizes,
+\fI\%ncurses\fP allocates arrays and reads data for the extended
+capabilities in the same order as the header information.
.PP
The extended string table contains values for string capabilities.
After the end of these values, it contains the names for each of
-the extended capabilities in order, e.g., booleans, then numbers and
+the extended capabilities in order, e.g., Booleans, then numbers and
finally strings.
.PP
By storing terminal descriptions in this way,
-\fBncurses\fP is able to provide a database useful with legacy applications,
+\fI\%ncurses\fP is able to provide a database useful with legacy
+applications,
as well as providing data for applications which need more than the
predefined capabilities.
See \fBuser_caps\fP(5) for an overview
-of the way \fBncurses\fP uses this extended information.
+of the way \fI\%ncurses\fP uses this extended information.
.PP
Applications which manipulate terminal data can use the definitions
described in \fBterm_variables\fP(3X) which associate the long capability
names with members of a \fBTERMTYPE\fP structure.
.
-.SS EXTENDED NUMBER FORMAT
+.SS "Extended Number Format"
On occasion, 16-bit signed integers are not large enough.
-With \fBncurses\fP 6.1, a new format was introduced by making a few changes
+With \fI\%ncurses\fP 6.1,
+a new format was introduced by making a few changes
to the legacy format:
.bP
a different magic number (octal 01036)
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.
-.SS Binary format
+of Boolean, number, and string capabilities.
+.SS "Binary Format"
X/Open Curses does not specify a format for the terminfo database.
System V curses used a directory-tree of binary files,
one per terminal description.
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.
+System V and X/Open Curses extensions.
See \fBterminfo\fP(5) for detailed
discussion of terminfo source compatibility issues.
.PP
except in a few less-used details
where it was found that the latter did not match X/Open Curses.
The format used by the other Unix versions
-can be matched by building ncurses
+can be matched by building \fI\%ncurses\fP
with different configuration options.
-.SS Magic codes
+.SS "Magic Codes"
The magic number in a binary terminfo file is the first 16-bits (two bytes).
Besides making it more reliable for the library to check that a file
is terminfo,
with 0433, 0435 as screen-dumps (see \fBscr_dump\fP(5)).
This implementation uses 01036 as a continuation of that sequence,
but with a different high-order byte to avoid confusion.
-.SS The TERMTYPE structure
+.SS "The \fITERMTYPE\fP Structure"
Direct access to the \fBTERMTYPE\fP structure is provided for legacy
applications.
Portable applications should use the \fBtigetflag\fP and related functions
described in \fBcurs_terminfo\fP(3X) for reading terminal capabilities.
-.SS Mixed-case terminal names
+.SS "Mixed-case Terminal Names"
A small number of terminal descriptions use uppercase characters in
their names.
If the underlying filesystem ignores the difference between
uppercase and lowercase,
-\fBncurses\fP represents the \*(``first character\*(''
+\fI\%ncurses\fP represents the \*(``first character\*(''
of the terminal name used as
the intermediate level of a directory tree in (two-character) hexadecimal form.
.SS Limits
-\fBncurses\fP stores compiled terminal descriptions
+\fI\%ncurses\fP stores compiled terminal descriptions
in three related formats,
described in the sections
.bP
The legacy storage format and the extended number format differ by
the types of numeric capability which they can store
(i.e., 16-bit versus 32-bit integers).
-The extended storage format introduced by ncurses 5.0 adds data to
-either of these formats.
+The extended storage format introduced by \fI\%ncurses\fP 5.0 adds data
+to either of these formats.
.PP
Some limitations apply:
.bP
As an example, here is a description for the Lear-Siegler
ADM\-3, a popular though rather stupid early terminal:
.PP
-.RS 4
.EX
adm3a|lsi adm3a,
am,
cuf1=\*^L, cup=\eE=%p1%{32}%+%c%p2%{32}%+%c, cuu1=\*^K,
home=\*^\*^, ind=\*^J,
.EE
-.RE
.PP
and a hexadecimal dump of the compiled terminal description:
.PP
-.ie n .in -2n
-.el .in +4n
+.if t .in +4n
+.ft \*(CW
.TS
-lp-1f(\*(CW).
+Lp-1.
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 ........ ........
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 ........ .
.TE
+.ft
.in
.SH AUTHORS
Thomas E. Dickey
.br
-extended terminfo format for ncurses 5.0
+extended terminfo format for \fI\%ncurses\fP 5.0
.br
-hashed database support for ncurses 5.6
+hashed database support for \fI\%ncurses\fP 5.6
.br
-extended number support for ncurses 6.1
+extended number support for \fI\%ncurses\fP 6.1
.sp
Eric S. Raymond
.br
projects / ncurses.git / blobdiff