TERM(5)                                                   TERM(5)

NAME
       term - format of compiled term file.

SYNOPSIS
       term

DESCRIPTION
       Compiled terminfo descriptions are placed under the direc-
       tory /usr/share/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  /usr/share/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.

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

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

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