-<!--
+<!--
****************************************************************************
- * Copyright 2018-2019,2020 Thomas E. Dickey *
+ * Copyright 2018-2020,2021 Thomas E. Dickey *
* Copyright 1998-2016,2017 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
- * @Id: term.5,v 1.38 2020/07/25 21:56:02 tom Exp @
+ * @Id: term.5,v 1.40 2021/08/15 19:38:47 tom Exp @
-->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML>
A two-level scheme is used to avoid a linear search of a huge UNIX
system directory: <STRONG>/usr/share/terminfo/c/name</STRONG> where <EM>name</EM> is the
name of the terminal, and <EM>c</EM> is the first character of <EM>name</EM>. Thus,
- <EM>act4</EM> can be found in the file <STRONG>/usr/share/terminfo/a/act4</STRONG>. Syn-
- onyms for the same terminal are implemented by multiple links to
- the same compiled file.
+ <EM>act4</EM> can be found in the file <STRONG>/usr/share/terminfo/a/act4</STRONG>.
+ Synonyms for the same terminal are implemented by multiple links
+ to the same compiled file.
<STRONG>hashed</STRONG> <STRONG>database</STRONG>
- Using Berkeley database, two types of records are stored: the ter-
- minfo data in the same format as stored in a directory tree with
- the terminfo's primary name as a key, and records containing only
- aliases pointing to the primary name.
+ Using Berkeley database, two types of records are stored: the
+ terminfo data in the same format as stored in a directory tree
+ with the terminfo's primary name as a key, and records containing
+ only aliases pointing to the primary name.
- If built to write hashed databases, <STRONG>ncurses</STRONG> can still read ter-
- minfo databases organized as a directory tree, but cannot write
+ If built to write hashed databases, <STRONG>ncurses</STRONG> 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.
- <STRONG>ncurses</STRONG> distinguishes the two cases in the TERMINFO and TER-
- MINFO_DIRS environment variable by assuming a directory tree for
- entries that correspond to an existing directory, and hashed data-
- base otherwise.
+ <STRONG>ncurses</STRONG> 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, and hashed
+ database otherwise.
</PRE><H3><a name="h3-LEGACY-STORAGE-FORMAT">LEGACY STORAGE FORMAT</a></H3><PRE>
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 order-
- ing or sign extension are made.
+ 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 <STRONG>tic</STRONG> program, and read by the rou-
- tine <STRONG><A HREF="curs_terminfo.3x.html">setupterm(3x)</A></STRONG>. The file is divided into six parts:
+ The compiled file is created with the <STRONG>tic</STRONG> program, and read by the
+
routine <STRONG><A HREF="curs_terminfo.3x.html">setupterm(3x)</A></STRONG>. The file is divided into six parts:
a) <EM>header</EM>,
are in the same order as the file <term.h>.
Short integers are signed, in the range -32768 to 32767. They are
- stored as two 8-bit bytes. The first byte contains the least signifi-
- cant 8 bits of the value, and the second byte contains the most signif-
- icant 8 bits. (Thus, the value represented is 256*second+first.) This
- format corresponds to the hardware of the VAX and PDP-11 (that is, lit-
- tle-endian machines). Machines where this does not correspond to the
- hardware must read the integers as two bytes and compute the little-
- endian value.
-
- Numbers in a terminal description, whether they are entries in the <EM>num-</EM>
- <EM>bers</EM> or <EM>strings</EM> table, are positive integers. Boolean flags 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.)
+ 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.
+
+ Numbers in a terminal description, whether they are entries in the
+ <EM>numbers</EM> or <EM>strings</EM> 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
The <EM>terminal</EM> <EM>names</EM> section comes after the <EM>header</EM>. It contains the
first line of the terminfo description, listing the various names for
- the terminal, separated by the "|" character. The <EM>terminal</EM> <EM>names</EM> sec-
- tion is terminated with an ASCII NUL character.
+ the terminal, separated by the "|" character. The <EM>terminal</EM> <EM>names</EM>
+ section is terminated with an ASCII NUL character.
- The <EM>boolean</EM> <EM>flags</EM> section has one byte for each flag. Boolean capabil-
- ities are either 1 or 0 (true or false) according to whether the termi-
- nal supports the given capability or not.
+ The <EM>boolean</EM> <EM>flags</EM> 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.
Between the <EM>boolean</EM> <EM>flags</EM> section and the <EM>number</EM> section, a null byte
will be inserted, if necessary, to ensure that the <EM>number</EM> section
predefined set of boolean, number or string capabilities.
The <STRONG>ncurses</STRONG> libraries and applications support extended terminfo binary
- format, allowing users to define capabilities which are loaded at run-
- time. 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. <STRONG>ncurses</STRONG> checks the size, and
- if it exceeds that due to the predefined data, continues to parse
- according to its own scheme.
+ 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. <STRONG>ncurses</STRONG> checks the
+ size, and if it exceeds that due to the predefined data, continues to
+ parse according to its own scheme.
First, it reads the extended header (5 short integers):
<STRONG>o</STRONG> changing the type for the <EM>number</EM> array from signed 16-bit integers
to signed 32-bit integers.
- To maintain compatibility, the library presents the same data struc-
- tures to direct users of the <STRONG>TERMTYPE</STRONG> structure as in previous formats.
- However, that cannot provide callers with the extended numbers. The
- library uses a similar but hidden data structure <STRONG>TERMTYPE2</STRONG> to provide
- data for the terminfo functions.
+ To maintain compatibility, the library presents the same data
+ structures to direct users of the <STRONG>TERMTYPE</STRONG> structure as in previous
+ formats. However, that cannot provide callers with the extended
+ numbers. The library uses a similar but hidden data structure
+ <STRONG>TERMTYPE2</STRONG> to provide data for the terminfo functions.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
</PRE><H3><a name="h3-setupterm">setupterm</a></H3><PRE>
Note that it is possible for <STRONG>setupterm</STRONG> to expect a different set of
- capabilities than are actually present in the file. Either the data-
- base may have been updated since <STRONG>setupterm</STRONG> has been recompiled (result-
- ing 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 <STRONG>setupterm</STRONG> 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 bool-
- ean, number, and string capabilities.
+ capabilities than are actually present in the file. Either the
+ database may have been updated since <STRONG>setupterm</STRONG> was 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 <STRONG>setupterm</STRONG> 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.
</PRE><H3><a name="h3-Binary-format">Binary format</a></H3><PRE>
UNIX System V curses used a directory-tree of binary files, one per
terminal description.
- Despite the consistent use of little-endian for numbers and the other-
- wise 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
- <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG> for detailed discussion of terminfo source compatibility
- issues.
+ 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 <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG> for detailed discussion of terminfo
+ source compatibility issues.
This implementation is by default compatible with the binary terminfo
format used by Solaris curses, except in a few less-used details where
</PRE><H3><a name="h3-The-TERMTYPE-structure">The TERMTYPE structure</a></H3><PRE>
- Direct access to the <STRONG>TERMTYPE</STRONG> structure is provided for legacy applica-
- tions. Portable applications should use the <STRONG>tigetflag</STRONG> and related
- functions described in <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG> for reading terminal capabili-
- ties.
+ Direct access to the <STRONG>TERMTYPE</STRONG> structure is provided for legacy
+ applications. Portable applications should use the <STRONG>tigetflag</STRONG> and
+ related functions described in <STRONG><A HREF="curs_terminfo.3x.html">curs_terminfo(3x)</A></STRONG> for reading terminal
+ capabilities.
</PRE><H3><a name="h3-Mixed-case-terminal-names">Mixed-case terminal names</a></H3><PRE>
A small number of terminal descriptions use uppercase characters in
their names. If the underlying filesystem ignores the difference
- between uppercase and lowercase, <STRONG>ncurses</STRONG> represents the "first charac-
- ter" of the terminal name used as the intermediate level of a directory
- tree in (two-character) hexadecimal form.
+ between uppercase and lowercase, <STRONG>ncurses</STRONG> represents the "first
+ character" of the terminal name used as the intermediate level of a
+ directory tree in (two-character) hexadecimal form.
</PRE><H2><a name="h2-EXAMPLE">EXAMPLE</a></H2><PRE>
- As an example, here is a description for the Lear-Siegler ADM-3, a pop-
- ular though rather stupid early terminal:
+ As an example, here is a description for the Lear-Siegler ADM-3, a
+ popular though rather stupid early terminal:
adm3a|lsi adm3a,
am,
</PRE><H2><a name="h2-LIMITS">LIMITS</a></H2><PRE>
Some limitations:
- <STRONG>o</STRONG> total compiled entries cannot exceed 4096 bytes in the legacy for-
- mat.
+ <STRONG>o</STRONG> total compiled entries cannot exceed 4096 bytes in the legacy
+ format.
<STRONG>o</STRONG> total compiled entries cannot exceed 32768 bytes in the extended
format.
<STRONG>o</STRONG> the name field cannot exceed 128 bytes.
Compiled entries are limited to 32768 bytes because offsets into the
- <EM>strings</EM> <EM>table</EM> use two-byte integers. The legacy format could have sup-
- ported 32768-byte entries, but was limited a virtual memory page's 4096
- bytes.
+ <EM>strings</EM> <EM>table</EM> use two-byte integers. The legacy format could have
+ supported 32768-byte entries, but was limited a virtual memory page's
+ 4096 bytes.
</PRE><H2><a name="h2-FILES">FILES</a></H2><PRE>
- /usr/share/terminfo/*/* compiled terminal capability data base
+ /usr/share/terminfo/*/* compiled terminal capability database
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
projects / ncurses.git / blobdiff