Compiled terminfo descriptions are placed under the directory
/usr/share/terminfo. Two configurations are supported (when building
- the ncurses libraries):
+ the ncurses libraries):
directorytree
A two-level scheme is used to avoid a linear search of a huge UNIX
@@ -74,12 +74,12 @@
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-
+ 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-
+ 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.
@@ -113,7 +113,7 @@
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
+ 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
@@ -159,11 +159,11 @@
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
+ 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
+ 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.
@@ -175,69 +175,100 @@
(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 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
+ 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
+ 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 is introduced by making a few changes to the legacy
+ 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 (0542)
+ o a different magic number (octal 01036)
- o changing the type for the number array from signed 16-bit integers
+ 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-
+ 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
+ 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-
+ 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.
- 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
+
+
+ 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
+ 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-
+
+
+ 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.
@@ -284,10 +315,10 @@
Some limitations:
- o total compiled entries cannot exceed 4096 bytes in the legacy for-
+ o total compiled entries cannot exceed 4096 bytes in the legacy for-
mat.
- o total compiled entries cannot exceed 32768 bytes in the extended
+ o total compiled entries cannot exceed 32768 bytes in the extended
format.
o the name field cannot exceed 128 bytes.
@@ -326,7 +357,15 @@