+'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc. *
+.\" Copyright 2018-2021,2023 Thomas E. Dickey *
+.\" Copyright 1998-2016,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: term.5,v 1.29 2018/05/19 21:09:25 tom Exp $
-.TH term 5
-.ie \n(.g .ds `` \(lq
-.el .ds `` ``
-.ie \n(.g .ds '' \(rq
-.el .ds '' ''
-.de NS
-.ie n .sp
-.el .sp .5
-.ie n .in +4
-.el .in +2
-.nf
-.ft C \" Courier
-..
-.de NE
-.fi
-.ft R
-.in -4
-..
+.\" $Id: term.5,v 1.62 2023/10/21 15:33:10 tom Exp $
+.TH term 5 2023-10-21 "ncurses 6.4" "File formats"
+.ie \n(.g \{\
+.ds `` \(lq
+.ds '' \(rq
+.ds ' \(aq
+.ds ^ \(ha
+.\}
+.el \{\
+.ie t .ds `` ``
+.el .ds `` ""
+.ie t .ds '' ''
+.el .ds '' ""
+.ds ' '
+.ds ^ ^
+.\}
+.ie n .ds CW R
+.el \{
+.ie \n(.g .ds CW CR
+.el .ds CW CW
+.\}
+.
.de bP
.ie n .IP \(bu 4
.el .IP \(bu 2
..
+.
.ds n 5
.ds d @TERMINFO@
.SH NAME
-term \- format of compiled term file.
+term \-
+compiled \fIterminfo\fR terminal description
.SH SYNOPSIS
.B term
.SH DESCRIPTION
The compiled file is created with the \fB@TIC@\fP program,
and read by the routine \fBsetupterm\fP(3X).
The file is divided into six parts:
-the header,
-terminal names,
-boolean flags,
-numbers,
-strings,
-and
-string table.
+.RS 5
+.TP 3
+a) \fIheader\fP,
+.TP 3
+b) \fIterminal names\fP,
+.TP 3
+c) \fIboolean flags\fP,
+.TP 3
+d) \fInumbers\fP,
+.TP 3
+e) \fIstrings\fP, and
+.TP 3
+f) \fIstring table\fP.
+.RE
.PP
-The header section begins the file.
+The \fIheader\fP section begins the file.
This section contains six short integers in the format
described below.
These integers are
.RS 5
.TP 5
-(1) the magic number (octal 0432);
+(1) the \fImagic number\fP (octal 0432);
.TP 5
-(2) the size, in bytes, of the names section;
+(2) the size, in bytes, of the \fIterminal names\fP section;
.TP 5
-(3) the number of bytes in the boolean section;
+(3) the number of bytes in the \fIboolean flags\fP section;
.TP 5
-(4) the number of short integers in the numbers section;
+(4) the number of short integers in the \fInumbers\fP section;
.TP 5
-(5) the number of offsets (short integers) in the strings section;
+(5) the number of offsets (short integers) in the \fIstrings\fP section;
.TP 5
-(6) the size, in bytes, of the string table.
+(6) the size, in bytes, of the \fIstring table\fP.
.RE
.PP
-Short integers are stored in two 8-bit bytes.
+The capabilities in the
+\fIboolean flags\fP,
+\fInumbers\fP, and
+\fIstrings\fP
+sections are in the same order as the file <term.h>.
+.PP
+Short integers are signed, in the range \-32768 to 32767.
+They are stored as 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 hardware of the \s-1VAX\s+1
+This format corresponds to the hardware of the \s-1VAX\s+1
and \s-1PDP\s+1-11 (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.
.PP
-The terminal names section comes next.
+Numbers in a terminal description,
+whether they are entries in the \fInumbers\fP or \fIstrings\fP table,
+are positive integers.
+Boolean flags are treated as positive one-byte integers.
+In each case, those positive integers represent a terminal capability.
+The terminal compiler @TIC@ uses negative integers to handle the cases where
+a capability is not available:
+.bP
+If a capability is absent from this terminal,
+@TIC@ stores a \-1 in the corresponding table.
+.IP
+The integer value \-1 is represented by two bytes 0377, 0377.
+.br
+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.
+.br
+.bP
+Other negative values are illegal.
+.PP
+The \fIterminal names\fP section comes after the \fIheader\fP.
It contains the first line of the terminfo description,
listing the various names for the terminal,
separated by the \*(``|\*('' character.
-The section is terminated with an \s-1ASCII NUL\s+1 character.
+The \fIterminal names\fP section is terminated
+with an \s-1ASCII NUL\s+1 character.
.PP
-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>.
+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 boolean section and the number section,
+Between the \fIboolean flags\fP section and the \fInumber\fP 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).
+to ensure that the \fInumber\fP section begins on an even byte
+This is a relic of the PDP\-11's word-addressed architecture,
+originally designed to avoid traps induced
+by addressing a word on an odd byte boundary.
All short integers are aligned on a short word boundary.
.PP
-The numbers section is similar to the flags 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.
-If the value represented is \-1, the capability is taken to be missing.
.PP
-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 \ec notation are stored in their
+The \fIstrings\fP section is also similar.
+Each capability is stored as a short integer.
+The capability value is an index into the \fIstring table\fP.
+.PP
+The \fIstring table\fP is the last section.
+It contains all of the values of string capabilities referenced in
+the \fIstrings\fP section.
+Each string is null-terminated.
+Special characters in \*^X or \ec notation are stored in their
interpreted form, not the printing representation.
Padding information $<nn> and parameter information %x are
stored intact in uninterpreted form.
-.PP
-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.
.SS EXTENDED STORAGE FORMAT
The previous section describes the conventional terminfo binary format.
With some minor variations of the offsets (see PORTABILITY),
names with members of a \fBTERMTYPE\fP structure.
.
.SS EXTENDED NUMBER FORMAT
-.PP
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
to the legacy format:
.bP
-a different magic number (0542)
+a different magic number (octal 01036)
.bP
changing the type for the \fInumber\fP array from signed 16-bit integers
to signed 32-bit integers.
The library uses a similar but hidden data structure \fBTERMTYPE2\fP
to provide data for the terminfo functions.
.SH PORTABILITY
+.SS setupterm
Note that it is possible for
.B setupterm
to expect a different set of capabilities
than are actually present in the file.
Either the database may have been updated since
.B setupterm
-has been recompiled
+was recompiled
(resulting in extra unrecognized entries in the file)
or the program may have been recompiled more recently
than the database was updated
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
+X/Open Curses does not specify a format for the terminfo database.
+UNIX System V curses used a directory-tree of binary files,
+one per terminal description.
.PP
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
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 \fBterminfo\fR(\*n) for detailed
+See \fBterminfo\fP(\*n) for detailed
discussion of terminfo source compatibility issues.
.PP
+This implementation is by default compatible with the binary
+terminfo format used by Solaris curses,
+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
+with different configuration options.
+.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,
+utilities such as \fBfile\fP(1) also use that to tell what the file-format is.
+System V defined more than one magic number,
+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
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.
-.PP
+.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
.SH EXAMPLE
As an example, here is a description for the Lear-Siegler
ADM\-3, a popular though rather stupid early terminal:
-.NS
+.PP
+.RS 4
+.EX
adm3a|lsi adm3a,
am,
cols#80, lines#24,
- bel=^G, clear=\032$<1>, cr=^M, cub1=^H, cud1=^J,
- cuf1=^L, cup=\\E=%p1%{32}%+%c%p2%{32}%+%c, cuu1=^K,
- home=^^, ind=^J,
-.NS
+ bel=\*^G, clear=\e032$<1>, cr=\*^M, cub1=\*^H, cud1=\*^J,
+ cuf1=\*^L, cup=\eE=%p1%{32}%+%c%p2%{32}%+%c, cuu1=\*^K,
+ home=\*^\*^, ind=\*^J,
+.EE
+.RE
.PP
and a hexadecimal dump of the compiled terminal description:
-.NS
-.ft CW
-\s-20000 1a 01 10 00 02 00 03 00 82 00 31 00 61 64 6d 33 ........ ..1.adm3
+.PP
+.ie n .in -2n
+.el .in +4n
+.TS
+lp-1f(\*(CW).
+0000 1a 01 10 00 02 00 03 00 82 00 31 00 61 64 6d 33 ........ ..1.adm3
0010 61 7c 6c 73 69 20 61 64 6d 33 61 00 00 01 50 00 a|lsi ad m3a...P.
0020 ff ff 18 00 ff ff 00 00 02 00 ff ff ff ff 04 00 ........ ........
-0030 ff ff ff ff ff ff ff ff 0a 00 25 00 27 00 ff ff ........ ..%.'...
-0040 29 00 ff ff ff ff 2b 00 ff ff 2d 00 ff ff ff ff ).....+. ..-.....
+0030 ff ff ff ff ff ff ff ff 0a 00 25 00 27 00 ff ff ........ ..%.\*'...
+0040 29 00 ff ff ff ff 2b 00 ff ff 2d 00 ff ff ff ff ).....+. ..\-.....
0050 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0060 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0070 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0120 ff ff ff ff ff ff 2f 00 07 00 0d 00 1a 24 3c 31 ....../. .....$<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 ........ .\s+2
-.ft R
-.NE
-.sp
+0150 00 08 00 0c 00 0b 00 0a 00 ........ .
+.TE
+.in
.SH LIMITS
Some limitations:
.bP
total compiled entries cannot exceed 32768 bytes in the extended format.
.bP
the name field cannot exceed 128 bytes.
+.PP
+Compiled entries are limited to 32768 bytes because offsets into the
+\fIstrings table\fP use two-byte integers.
+The legacy format could have supported 32768-byte entries,
+but was limited a virtual memory page's 4096 bytes.
.SH FILES
-\*d/*/* compiled terminal capability data base
-.SH SEE ALSO
-\fBcurses\fR(3X), \fBterminfo\fR(\*n).
+.TP
+.I \*d
+compiled terminal description database
.SH AUTHORS
Thomas E. Dickey
.br
.sp
Eric S. Raymond
.br
-documented legacy terminfo format, e.g., from pcurses.
+documented legacy terminfo format, e.g., from \fIpcurses\fP.
+.SH SEE ALSO
+\fB\%curses\fP(3X),
+\fB\%curs_terminfo\fP(3X),
+\fB\%terminfo\fP(\*n)
projects / ncurses.git / blobdiff