-<!--
+<!--
****************************************************************************
- * Copyright (c) 1998-2018,2019 Free Software Foundation, Inc. *
+ * 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 *
* 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 1.32 2019/01/12 23:11:08 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>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts">
<TITLE>term 5</TITLE>
-<link rev=made href="mailto:bug-ncurses@gnu.org">
+<link rel="author" href="mailto:bug-ncurses@gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</HEAD>
<BODY>
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 header,
- terminal names, boolean flags, numbers, strings, and string table.
+ 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:
- The header section begins the file. This section contains six short
+ a) <EM>header</EM>,
+
+ b) <EM>terminal</EM> <EM>names</EM>,
+
+ c) <EM>boolean</EM> <EM>flags</EM>,
+
+ d) <EM>numbers</EM>,
+
+ e) <EM>strings</EM>, and
+
+ f) <EM>string</EM> <EM>table</EM>.
+
+ The <EM>header</EM> 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 <EM>magic</EM> <EM>number</EM> (octal 0432);
+
+ (2) the size, in bytes, of the <EM>terminal</EM> <EM>names</EM> section;
+
+ (3) the number of bytes in the <EM>boolean</EM> <EM>flags</EM> section;
- (2) the size, in bytes, of the names section;
+ (4) the number of short integers in the <EM>numbers</EM> section;
- (3) the number of bytes in the boolean section;
+ (5) the number of offsets (short integers) in the <EM>strings</EM> section;
- (4) the number of short integers in the numbers section;
+ (6) the size, in bytes, of the <EM>string</EM> <EM>table</EM>.
- (5) the number of offsets (short integers) in the strings section;
+ The capabilities in the <EM>boolean</EM> <EM>flags</EM>, <EM>numbers</EM>, and <EM>strings</EM> sections
+ are in the same order as the file <term.h>.
- (6) the size, in bytes, of the string table.
+ 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.
- 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.
+ 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
+ available:
- 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.
+ <STRONG>o</STRONG> If a capability is absent from this terminal, tic stores a -1 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 -1 is represented by two bytes 0377, 0377.
+ Absent boolean values are represented by the byte 0 (false).
- 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.
+ <STRONG>o</STRONG> If a capability has been canceled from this terminal, tic stores a
+ -2 in the corresponding table.
- 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 integer value -2 is represented by two bytes 0377, 0376.
+ The boolean value -2 is represented by the byte 0376.
- 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.
+ <STRONG>o</STRONG> Other negative values are illegal.
- 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.
+ 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>
+ section is terminated with an ASCII NUL character.
+
+ 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
+ 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 <EM>numbers</EM> section is similar to the <EM>boolean</EM> <EM>flags</EM> section. Each
+ capability takes up two bytes, and is stored as a little-endian short
+ integer.
+
+ The <EM>strings</EM> section is also similar. Each capability is stored as a
+ short integer. The capability value is an index into the <EM>string</EM> <EM>table</EM>.
+
+ The <EM>string</EM> <EM>table</EM> is the last section. It contains all of the values of
+ string capabilities referenced in the <EM>strings</EM> 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 <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):
(5) size of the extended string table in bytes
- The count- and size-values for the extended string table include the
+ The count- and size-values for the extended string table include the
extended capability <EM>names</EM> as well as extended capability <EM>values</EM>.
Using the counts and sizes, <STRONG>ncurses</STRONG> 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.
- 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 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
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
+ 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.
</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 <STRONG>ncurses</STRONG>
- 6.1, a new format was introduced by making a few changes to the legacy
+ 6.1, a new format was introduced by making a few changes to the legacy
format:
<STRONG>o</STRONG> a different magic number (octal 01036)
- <STRONG>o</STRONG> changing the type for the <EM>number</EM> array from signed 16-bit 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.
+ 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
+ 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>
- 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
+ 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 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.
-
- 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
+ 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
+ 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 <STRONG>file</STRONG> also use that to tell what
- the file-format is. System V defined more than one magic number, with
+ 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 <STRONG>file</STRONG> 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 <STRONG><A HREF="scr_dump.5.html">scr_dump(5)</A></STRONG>). This implementation uses
- 01036 as a continuation of that sequence, but with a different high-
+ 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 <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.
+ 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
+ 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
+ <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
+ 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