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term(5)								       term(5)

NAME
       term - format of	compiled term file.

SYNOPSIS
       term

DESCRIPTION
   STORAGE LOCATION
       Compiled	  terminfo   descriptions   are	 placed	 under	the  directory
       /usr/share/misc/terminfo.   Two	configurations	are  supported	 (when
       building	the ncurses libraries):

       directory tree
	    A two-level	scheme is used to avoid	a linear search	of a huge UNIX
	    system directory: /usr/share/misc/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/misc/ter-
	    minfo/a/act4.   Synonyms  for the same terminal are	implemented by
	    multiple links to the same compiled	file.

       hashed database
	    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
	    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.

   STORAGE FORMAT
       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.	The file is divided into six parts: the	header,	termi-
       nal names, boolean flags, numbers, 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*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  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.

       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	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  final  section is the string table.	 It contains all the values of
       string capabilities referenced in the string section.  Each  string  is
       null terminated.

   EXTENDED STORAGE FORMAT
       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)	 size of the extended string table in bytes.

	    (5)	 last offset of	the extended string table in bytes.

       Using the counts	and sizes, ncurses allocates arrays and	reads data for
       the extended capabilties	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.

PORTABILITY
       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
       boolean,	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
       issues.

EXAMPLE
       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=\E=%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		       ........	.

LIMITS
       Some limitations: total compiled	entries	cannot exceed 4096 bytes.  The
       name field cannot exceed	128 bytes.

FILES
       /usr/share/misc/terminfo/*/*  compiled terminal capability data base

SEE ALSO
       curses(3X), terminfo(5).

AUTHORS
       Thomas E. Dickey
       extended	terminfo format	for ncurses 5.0
       hashed database support for ncurses 5.6

       Eric S. Raymond

								       term(5)

NAME | SYNOPSIS | DESCRIPTION | PORTABILITY | EXAMPLE | LIMITS | FILES | SEE ALSO | AUTHORS

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