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+<!--
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- * Copyright (c) 1998-2016,2017 Free Software Foundation, Inc. *
+ * Copyright 2018-2019,2020 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 *
* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
- * @Id: term.5,v 1.27 2017/12/16 21:27:20 tom Exp @
+ * @Id: term.5,v 1.38 2020/07/25 21:56:02 tom Exp @
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<H1 class="no-header">term 5</H1>
<PRE>
-<STRONG><A HREF="term.5.html">term(5)</A></STRONG> File Formats Manual <STRONG><A HREF="term.5.html">term(5)</A></STRONG>
+<B><A HREF="term.5.html">term(5)</A></B> File Formats Manual <B><A HREF="term.5.html">term(5)</A></B>
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
- <STRONG>term</STRONG>
+ <B>term</B>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
</PRE><H3><a name="h3-STORAGE-LOCATION">STORAGE LOCATION</a></H3><PRE>
Compiled terminfo descriptions are placed under the directory
- <STRONG>/usr/share/terminfo</STRONG>. Two configurations are supported (when building
- the ncurses libraries):
+ <B>/usr/share/terminfo</B>. Two configurations are supported (when building
+ the <B>ncurses</B> libraries):
- <STRONG>directory</STRONG> <STRONG>tree</STRONG>
+ <B>directory</B> <B>tree</B>
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.
-
- <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.
-
- If built to write hashed databases, ncurses can still read ter-
- minfo databases organized as a directory tree, but cannot write
+ system directory: <B>/usr/share/terminfo/c/name</B> where <I>name</I> is the
+ name of the terminal, and <I>c</I> is the first character of <I>name</I>. Thus,
+ <I>act4</I> can be found in the file <B>/usr/share/terminfo/a/act4</B>.
+ Synonyms for the same terminal are implemented by multiple links
+ to the same compiled file.
+
+ <B>hashed</B> <B>database</B>
+ 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, <B>ncurses</B> 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.
- ncurses 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.
+ <B>ncurses</B> 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 header,
- terminal names, boolean flags, numbers, strings, and string table.
+ The compiled file is created with the <B>tic</B> program, and read by the
+ routine <B><A HREF="curs_terminfo.3X.html">setupterm(3X)</A></B>. The file is divided into six parts:
- The header section begins the file. This section contains six short
+ a) <I>header</I>,
+
+ b) <I>terminal</I> <I>names</I>,
+
+ c) <I>boolean</I> <I>flags</I>,
+
+ d) <I>numbers</I>,
+
+ e) <I>strings</I>, and
+
+ f) <I>string</I> <I>table</I>.
+
+ The <I>header</I> section begins the file. This section contains six short
integers in the format described below. These integers are
- (1) the magic number (octal 0432);
+ (1) the <I>magic</I> <I>number</I> (octal 0432);
+
+ (2) the size, in bytes, of the <I>terminal</I> <I>names</I> section;
+
+ (3) the number of bytes in the <I>boolean</I> <I>flags</I> section;
+
+ (4) the number of short integers in the <I>numbers</I> section;
+
+ (5) the number of offsets (short integers) in the <I>strings</I> section;
- (2) the size, in bytes, of the names section;
+ (6) the size, in bytes, of the <I>string</I> <I>table</I>.
- (3) the number of bytes in the boolean section;
+ The capabilities in the <I>boolean</I> <I>flags</I>, <I>numbers</I>, and <I>strings</I> sections
+ are in the same order as the file <term.h>.
- (4) the number of short integers in the numbers section;
+ 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.)
+ 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.
- (5) the number of offsets (short integers) in the strings section;
+ Numbers in a terminal description, whether they are entries in the
+ <I>numbers</I> or <I>strings</I> 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:
- (6) the size, in bytes, of the string table.
+ <B>o</B> If a capability is absent from this terminal, tic stores a -1 in
+ the corresponding 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*sec-
- ond+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 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.
+ The integer value -1 is represented by two bytes 0377, 0377.
+ Absent boolean values are represented by the byte 0 (false).
- The terminal names section comes next. 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
- ASCII NUL character.
+ <B>o</B> If a capability has been canceled from this terminal, tic stores a
+ -2 in the corresponding table.
- 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 integer value -2 is represented by two bytes 0377, 0376.
+ The boolean value -2 is represented by the byte 0376.
- 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.
+ <B>o</B> Other negative values are illegal.
- 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 <I>terminal</I> <I>names</I> section comes after the <I>header</I>. It contains the
+ first line of the terminfo description, listing the various names for
+ the terminal, separated by the "|" character. The <I>terminal</I> <I>names</I>
+ section is terminated with an ASCII NUL character.
- 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 begin-
- ning 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 <I>boolean</I> <I>flags</I> 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.
- 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.
+ Between the <I>boolean</I> <I>flags</I> section and the <I>number</I> section, a null byte
+ will be inserted, if necessary, to ensure that the <I>number</I> 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.
+
+ The <I>numbers</I> section is similar to the <I>boolean</I> <I>flags</I> section. Each
+ capability takes up two bytes, and is stored as a little-endian short
+ integer.
+
+ The <I>strings</I> section is also similar. Each capability is stored as a
+ short integer. The capability value is an index into the <I>string</I> <I>table</I>.
+
+ The <I>string</I> <I>table</I> is the last section. It contains all of the values of
+ string capabilities referenced in the <I>strings</I> section. Each string is
+ null-terminated. 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.
</PRE><H3><a name="h3-EXTENDED-STORAGE-FORMAT">EXTENDED STORAGE FORMAT</a></H3><PRE>
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
+ 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.
- The ncurses 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. ncurses checks the size, and
- if it exceeds that due to the predefined data, continues to parse
- according to its own scheme.
+ The <B>ncurses</B> 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. <B>ncurses</B> 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):
(3) count of extended string capabilities
- (4) size of the extended string table in bytes.
+ (4) count of the items in extended string table
- (5) last offset of the extended string table in bytes.
+ (5) size of the extended string table in bytes
- Using the counts and sizes, ncurses allocates arrays and reads data for
+ The count- and size-values for the extended string table include the
+ extended capability <I>names</I> as well as extended capability <I>values</I>.
+
+ Using the counts and sizes, <B>ncurses</B> allocates arrays and reads data for
the extended capabilities in the same order as the header information.
The extended string table contains values for string capabilities.
finally strings.
Applications which manipulate terminal data can use the definitions
- described in <STRONG><A HREF="term_variables.3x.html">term_variables(3x)</A></STRONG> which associate the long capability
- names with members of a <STRONG>TERMTYPE</STRONG> structure.
+ described in <B><A HREF="term_variables.3X.html">term_variables(3X)</A></B> which associate the long capability
+ names with members of a <B>TERMTYPE</B> structure.
</PRE><H3><a name="h3-EXTENDED-NUMBER-FORMAT">EXTENDED NUMBER FORMAT</a></H3><PRE>
- On occasion, 16-bit signed integers are not large enough. With ncurses
- 6.1, a new format is introduced by making a few changes to the legacy
+ On occasion, 16-bit signed integers are not large enough. With <B>ncurses</B>
+ 6.1, a new format was introduced by making a few changes to the legacy
format:
- <STRONG>o</STRONG> a different magic number (0542)
+ <B>o</B> a different magic number (octal 01036)
- <STRONG>o</STRONG> changing the type for the <EM>number</EM> array from signed 16-bit integers
+ <B>o</B> changing the type for the <I>number</I> 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 <B>TERMTYPE</B> structure as in previous
+ formats. However, that cannot provide callers with the extended
+ numbers. The library uses a similar but hidden data structure
+ <B>TERMTYPE2</B> to provide data for the terminfo functions.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><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.
-
- 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.
-
- 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.
+</PRE><H3><a name="h3-setupterm">setupterm</a></H3><PRE>
+ Note that it is possible for <B>setupterm</B> to expect a different set of
+ capabilities than are actually present in the file. Either the
+ database may have been updated since <B>setupterm</B> 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 <B>setupterm</B> 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>
+ 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.
+
+ 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 <B><A HREF="terminfo.5.html">terminfo(5)</A></B> 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
+ 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.
+
+
+</PRE><H3><a name="h3-Magic-codes">Magic codes</a></H3><PRE>
+ 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 <B>file</B> 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 <B><A HREF="scr_dump.5.html">scr_dump(5)</A></B>). This implementation uses
+ 01036 as a continuation of that sequence, but with a different high-
+ order byte to avoid confusion.
+
+
+</PRE><H3><a name="h3-The-TERMTYPE-structure">The TERMTYPE structure</a></H3><PRE>
+ Direct access to the <B>TERMTYPE</B> structure is provided for legacy
+ applications. Portable applications should use the <B>tigetflag</B> and
+ related functions described in <B><A HREF="curs_terminfo.3X.html">curs_terminfo(3X)</A></B> 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, ncurses 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, <B>ncurses</B> 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.
+ <B>o</B> total compiled entries cannot exceed 4096 bytes in the legacy
+ format.
- <STRONG>o</STRONG> total compiled entries cannot exceed 32768 bytes in the extended
+ <B>o</B> total compiled entries cannot exceed 32768 bytes in the extended
format.
- <STRONG>o</STRONG> the name field cannot exceed 128 bytes.
+ <B>o</B> the name field cannot exceed 128 bytes.
+
+ Compiled entries are limited to 32768 bytes because offsets into the
+ <I>strings</I> <I>table</I> 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>
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
- <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>.
+ <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="terminfo.5.html">terminfo(5)</A></B>.
</PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
- <STRONG><A HREF="term.5.html">term(5)</A></STRONG>
+ <B><A HREF="term.5.html">term(5)</A></B>
</PRE>
<div class="nav">
<ul>
<li><a href="#h3-EXTENDED-NUMBER-FORMAT">EXTENDED NUMBER FORMAT</a></li>
</ul>
</li>
-<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
+<li><a href="#h2-PORTABILITY">PORTABILITY</a>
+<ul>
+<li><a href="#h3-setupterm">setupterm</a></li>
+<li><a href="#h3-Binary-format">Binary format</a></li>
+<li><a href="#h3-Magic-codes">Magic codes</a></li>
+<li><a href="#h3-The-TERMTYPE-structure">The TERMTYPE structure</a></li>
+<li><a href="#h3-Mixed-case-terminal-names">Mixed-case terminal names</a></li>
+</ul>
+</li>
<li><a href="#h2-EXAMPLE">EXAMPLE</a></li>
<li><a href="#h2-LIMITS">LIMITS</a></li>
<li><a href="#h2-FILES">FILES</a></li>