- Compiled terminfo descriptions are placed under the direc-
- tory @DATADIR@/terminfo. In order to avoid a linear
- search of a huge UNIX system directory, a two-level scheme
- is used: /c/name where name is the name of the terminal,
- and c is the first character of name. Thus, act4 can be
- found in the file @DATADIR@/terminfo/a/act4. Synonyms for
- the same terminal are implemented by multiple links to the
- same compiled file.
-
- 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.
-
- The compiled file is created with the tic program, and
- read by the routine setupterm. The file is divided into
- six parts: the header, terminal names, boolean flags, num-
- bers, strings, and string table.
-
- The header section begins the file. This section contains
- six short integers in the format described below. These
- integers are (1) the magic number (octal 0432); (2) the
- size, in bytes, of the names section; (3) the number of
- bytes in the boolean section; (4) the number of short
- integers in the numbers section; (5) the number of offsets
- (short integers) in the strings section; (6) the size, in
- bytes, of the string 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*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 hard-
- ware 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.
-
- The terminal names section comes next. It contains the
- first line of the terminfo description, listing the vari-
- ous names for the terminal, separated by the `|' charac-
- ter. The section is terminated with an ASCII NUL charac-
- ter.
-
- 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>.
-
- 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.
-
- 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 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 \c notation are
- stored in their interpreted form, not the printing repre-
- sentation. Padding information $<nn> and parameter infor-
- mation %x are stored intact in uninterpreted form.
-
- The final section is the string table. It contains all
- the values of string capabilities referenced in the string
- section. Each string is null terminated.
-
- Note that it is possible for setupterm to expect a differ-
- ent set of capabilities than are actually present in the
- file. Either the database may have been updated since
- setupterm has been recompiled (resulting in extra unrecog-
- nized entries in the file) or the program may have been
- recompiled more recently than the database was updated
- (resulting in missing entries). The routine setupterm
- must be prepared for both possibilities - this is why the
- numbers and sizes are included. Also, new capabilities
- must always be added at the end of the lists of boolean,
- number, and string capabilities.
-
- Despite the consistent use of little-endian for numbers
- and the otherwise self-describing format, it is not wise
- to count on portability of binary terminfo entries between
- commercial UNIX versions. The problem is that there are
- at least three versions of terminfo (under HP-UX, AIX, and
- OSF/1) which diverged from System V terminfo after SVr1,
- and have added extension capabilities to the string table
- that (in the binary format) collide with System V and XSI
- Curses extensions. See terminfo(5) for detailed discus-
- sion of terminfo source compatibility issues.
-
- As an example, here is a hex dump of the description for
- the Lear-Siegler ADM-3, a popular though rather stupid
- early terminal:
-
- adm3a|lsi adm3a,
- am,
- cols#80, lines#24,
- bel=^G, clear= 32$<1>, cr=^M, cub1=^H, cud1=^J,
- cuf1=^L, cup==%p1%{32}%+%c%p2%{32}%+%c, cuu1=^K,
- home=^^, ind=^J,
-
- 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 ).....+. ..-.....
- 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 ........ ........
- 0080 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 0090 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 00a0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 00b0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 00c0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 00d0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 00e0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 00f0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 0100 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
- 0110 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 ........ .
-
-
- Some limitations: total compiled entries cannot exceed
- 4096 bytes. The name field cannot exceed 128 bytes.
+
+ Compiled terminfo descriptions are placed under the directory
+ /usr/share/terminfo. Two configurations are supported (when building
+ the ncurses libraries):
-
-
FILES
- @DATADIR@/terminfo/*/* compiled terminal capability data
- base
+ directorytree
+ A two-level scheme is used to avoid a linear search of a huge UNIX
+ system directory: /usr/share/terminfo/c/name where name is the
+ name of the terminal, and c is the first character of name. Thus,
+ act4 can be found in the file /usr/share/terminfo/a/act4. Syn-
+ onyms for the same terminal are implemented by multiple links to
+ the same compiled file.
+ hasheddatabase
+ 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.
-
-
SEE ALSO
- curses(3x), terminfo(5).
+ If built to write hashed databases, ncurses can still read ter-
+ minfo 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.
+
+
+
+ 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.
+
+ The compiled file is created with the tic program, and read by the rou-
+ tine setupterm(3x). The file is divided into six parts:
+
+ a) header,
+
+ b) terminalnames,
+
+ c) booleanflags,
+
+ d) numbers,
+
+ e) strings, and
+
+ f) stringtable.
+
+ The header section begins the file. This section contains six short
+ integers in the format described below. These integers are
+
+ (1) the magicnumber (octal 0432);
+
+ (2) the size, in bytes, of the terminalnames section;
+
+ (3) the number of bytes in the booleanflags section;
+
+ (4) the number of short integers in the numbers section;
+
+ (5) the number of offsets (short integers) in the strings section;
+
+ (6) the size, in bytes, of the stringtable.
+
+ The capabilities in the booleanflags, numbers, and strings sections
+ 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 num-
+ bers or strings 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:
+
+ o If a capability is absent from this terminal, tic stores a -1 in
+ the corresponding table.
+
+ The integer value -1 is represented by two bytes 0377, 0377.
+ Absent boolean values are represented by the byte 0 (false).
+
+ o If a capability has been canceled from this terminal, tic stores a
+ -2 in the corresponding table.
+
+ The integer value -2 is represented by two bytes 0377, 0376.
+ The boolean value -2 is represented by the byte 0376.
+
+ o Other negative values are illegal.
+
+ The terminalnames section comes after the header. It contains the
+ first line of the terminfo description, listing the various names for
+ the terminal, separated by the "|" character. The terminalnames sec-
+ tion is terminated with an ASCII NUL character.
+
+ The booleanflags 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.
+
+ Between the booleanflags 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 to avoid traps induced by addressing
+ a word on an odd byte boundary. All short integers are aligned on a
+ short word boundary.
+
+ The numbers section is similar to the booleanflags section. Each
+ capability takes up two bytes, and is stored as a little-endian short
+ integer.
+
+ The strings section is also similar. Each capability is stored as a
+ short integer. The capability value is an index into the stringtable.
+
+ The stringtable is the last section. It contains all of the values of
+ string capabilities referenced in the strings 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.
+
+
+
+ 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.
+
+ 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.
+
+ First, it reads the extended header (5 short integers):
+
+ (1) count of extended boolean capabilities
+
+ (2) count of extended numeric capabilities
+
+ (3) count of extended string capabilities
+
+ (4) count of the items in extended string table
+
+ (5) size of the extended string table in bytes
+
+ The count- and size-values for the extended string table include the
+ extended capability names as well as extended capability values.
+
+ Using the counts and sizes, ncurses 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
+ finally strings.
+
+ Applications which manipulate terminal data can use the definitions
+ described in term_variables(3x) which associate the long capability
+ names with members of a TERMTYPE structure.
+
+
+
+ On occasion, 16-bit signed integers are not large enough. With ncurses
+ 6.1, a new format was introduced by making a few changes to the legacy
+ format:
+
+ o a different magic number (octal 01036)
+
+ o changing the type for the number 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 TERMTYPE structure as in previous formats.
+ However, that cannot provide callers with the extended numbers. The
+ library uses a similar but hidden data structure TERMTYPE2 to provide
+ data for the terminfo functions.
+
+
+
+ Note that it is possible for setupterm to expect a different set of
+ capabilities than are actually present in the file. Either the data-
+ base may have been updated since setupterm 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 setupterm 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.
+
+
+
+ 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
+ terminfo(5) 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.
+
+
+
+ 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 file 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 scr_dump(5)). This implementation uses
+ 01036 as a continuation of that sequence, but with a different high-
+ order byte to avoid confusion.
+
+
+
+ Direct access to the TERMTYPE structure is provided for legacy applica-
+ tions. Portable applications should use the tigetflag and related
+ functions described in curs_terminfo(3x) for reading terminal capabili-
+ ties.
+
+
+
+ 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.
+
+
+
+ Some limitations:
+
+ o total compiled entries cannot exceed 4096 bytes in the legacy for-
+ mat.
+
+ o total compiled entries cannot exceed 32768 bytes in the extended
+ format.
+
+ o the name field cannot exceed 128 bytes.
+ Compiled entries are limited to 32768 bytes because offsets into the
+ stringstable use two-byte integers. The legacy format could have sup-
+ ported 32768-byte entries, but was limited a virtual memory page's 4096
+ bytes.
+
+ Thomas E. Dickey
+ extended terminfo format for ncurses 5.0
+ hashed database support for ncurses 5.6
+ extended number support for ncurses 6.1
+ Eric S. Raymond
+ documented legacy terminfo format, e.g., from pcurses.
+ term(5)