1term(5) File Formats Manual term(5)
2
6 term - format of compiled term file.
7
9 term
10
12 STORAGE LOCATION
13 Compiled terminfo descriptions are placed under the directory
14 /usr/share/terminfo. Two configurations are supported (when building
15 the ncurses libraries):
16 directory tree
18 A two-level scheme is used to avoid a linear search of a huge UNIX
19 system directory: /usr/share/terminfo/c/name where name is the
20 name of the terminal, and c is the first character of name. Thus,
21 act4 can be found in the file /usr/share/terminfo/a/act4. Syn‐
22 onyms for the same terminal are implemented by multiple links to
23 the same compiled file.
24 hashed database
26 Using Berkeley database, two types of records are stored: the ter‐
27 minfo data in the same format as stored in a directory tree with
28 the terminfo's primary name as a key, and records containing only
29 aliases pointing to the primary name.
30 If built to write hashed databases, ncurses can still read ter‐
32 minfo databases organized as a directory tree, but cannot write
33 entries into the directory tree. It can write (or rewrite)
34 entries in the hashed database.
35 ncurses distinguishes the two cases in the TERMINFO and TER‐
37 MINFO_DIRS environment variable by assuming a directory tree for
38 entries that correspond to an existing directory, and hashed data‐
39 base otherwise.
40 LEGACY STORAGE FORMAT
42 The format has been chosen so that it will be the same on all hardware.
43 An 8 or more bit byte is assumed, but no assumptions about byte order‐
44 ing or sign extension are made.
45 The compiled file is created with the tic program, and read by the rou‐
47 tine setupterm(3X). The file is divided into six parts: the header,
48 terminal names, boolean flags, numbers, strings, and string table.
49 The header section begins the file. This section contains six short
51 integers in the format described below. These integers are
52 (1) the magic number (octal 0432);
54 (2) the size, in bytes, of the names section;
56 (3) the number of bytes in the boolean section;
58 (4) the number of short integers in the numbers section;
60 (5) the number of offsets (short integers) in the strings section;
62 (6) the size, in bytes, of the string table.
64 Short integers are stored in two 8-bit bytes. The first byte contains
66 the least significant 8 bits of the value, and the second byte contains
67 the most significant 8 bits. (Thus, the value represented is 256*sec‐
68 ond+first.) The value -1 is represented by the two bytes 0377, 0377;
69 other negative values are illegal. This value generally means that the
70 corresponding capability is missing from this terminal. Note that this
71 format corresponds to the hardware of the VAX and PDP-11 (that is, lit‐
72 tle-endian machines). Machines where this does not correspond to the
73 hardware must read the integers as two bytes and compute the little-
74 endian value.
75 The terminal names section comes next. It contains the first line of
77 the terminfo description, listing the various names for the terminal,
78 separated by the “|” character. The section is terminated with an
79 ASCII NUL character.
80 The boolean flags have one byte for each flag. This byte is either 0
82 or 1 as the flag is present or absent. The capabilities are in the
83 same order as the file <term.h>.
84 Between the boolean section and the number section, a null byte will be
86 inserted, if necessary, to ensure that the number section begins on an
87 even byte (this is a relic of the PDP-11's word-addressed architecture,
88 originally designed in to avoid IOT traps induced by addressing a word
89 on an odd byte boundary). All short integers are aligned on a short
90 word boundary.
91 The numbers section is similar to the flags section. Each capability
93 takes up two bytes, and is stored as a little-endian short integer. If
94 the value represented is -1, the capability is taken to be missing.
95 The strings section is also similar. Each capability is stored as a
97 short integer, in the format above. A value of -1 means the capability
98 is missing. Otherwise, the value is taken as an offset from the begin‐
99 ning of the string table. Special characters in ^X or \c notation are
100 stored in their interpreted form, not the printing representation.
101 Padding information $<nn> and parameter information %x are stored
102 intact in uninterpreted form.
103 The final section is the string table. It contains all the values of
105 string capabilities referenced in the string section. Each string is
106 null terminated.
107 EXTENDED STORAGE FORMAT
109 The previous section describes the conventional terminfo binary format.
110 With some minor variations of the offsets (see PORTABILITY), the same
111 binary format is used in all modern UNIX systems. Each system uses a
112 predefined set of boolean, number or string capabilities.
113 The ncurses libraries and applications support extended terminfo binary
115 format, allowing users to define capabilities which are loaded at run‐
116 time. This extension is made possible by using the fact that the other
117 implementations stop reading the terminfo data when they have reached
118 the end of the size given in the header. ncurses checks the size, and
119 if it exceeds that due to the predefined data, continues to parse
120 according to its own scheme.
121 First, it reads the extended header (5 short integers):
123 (1) count of extended boolean capabilities
125 (2) count of extended numeric capabilities
127 (3) count of extended string capabilities
129 (4) size of the extended string table in bytes.
131 (5) last offset of the extended string table in bytes.
133 Using the counts and sizes, ncurses allocates arrays and reads data for
135 the extended capabilities in the same order as the header information.
136 The extended string table contains values for string capabilities.
138 After the end of these values, it contains the names for each of the
139 extended capabilities in order, e.g., booleans, then numbers and
140 finally strings.
141 Applications which manipulate terminal data can use the definitions
143 described in term_variables(3X) which associate the long capability
144 names with members of a TERMTYPE structure.
145 EXTENDED NUMBER FORMAT
147 On occasion, 16-bit signed integers are not large enough. With ncurses
148 6.1, a new format is introduced by making a few changes to the legacy
149 format:
150 · a different magic number (0542)
152 · changing the type for the number array from signed 16-bit integers
154 to signed 32-bit integers.
155 To maintain compatibility, the library presents the same data struc‐
157 tures to direct users of the TERMTYPE structure as in previous formats.
158 However, that cannot provide callers with the extended numbers. The
159 library uses a similar but hidden data structure TERMTYPE2 to provide
160 data for the terminfo functions.
161
163 Note that it is possible for setupterm to expect a different set of
164 capabilities than are actually present in the file. Either the data‐
165 base may have been updated since setupterm has been recompiled (result‐
166 ing in extra unrecognized entries in the file) or the program may have
167 been recompiled more recently than the database was updated (resulting
168 in missing entries). The routine setupterm must be prepared for both
169 possibilities - this is why the numbers and sizes are included. Also,
170 new capabilities must always be added at the end of the lists of bool‐
171 ean, number, and string capabilities.
172 Despite the consistent use of little-endian for numbers and the other‐
174 wise self-describing format, it is not wise to count on portability of
175 binary terminfo entries between commercial UNIX versions. The problem
176 is that there are at least three versions of terminfo (under HP-UX,
177 AIX, and OSF/1) which diverged from System V terminfo after SVr1, and
178 have added extension capabilities to the string table that (in the
179 binary format) collide with System V and XSI Curses extensions. See
180 terminfo(5) for detailed discussion of terminfo source compatibility
181 issues.
182 Direct access to the TERMTYPE structure is provided for legacy applica‐
184 tions. Portable applications should use the tigetflag and related
185 functions described in curs_terminfo(3X) for reading terminal capabili‐
186 ties.
187 A small number of terminal descriptions use uppercase characters in
189 their names. If the underlying filesystem ignores the difference
190 between uppercase and lowercase, ncurses represents the “first charac‐
191 ter” of the terminal name used as the intermediate level of a directory
192 tree in (two-character) hexadecimal form.
193
195 As an example, here is a description for the Lear-Siegler ADM-3, a pop‐
196 ular though rather stupid early terminal:
197 adm3a|lsi adm3a,
199 am,
200 cols#80, lines#24,
201 bel=^G, clear= 32$<1>, cr=^M, cub1=^H, cud1=^J,
202 cuf1=^L, cup=\E=%p1%{32}%+%c%p2%{32}%+%c, cuu1=^K,
203 home=^^, ind=^J,
204 and a hexadecimal dump of the compiled terminal description:
207 0000 1a 01 10 00 02 00 03 00 82 00 31 00 61 64 6d 33 ........ ..1.adm3
209 0010 61 7c 6c 73 69 20 61 64 6d 33 61 00 00 01 50 00 a|lsi ad m3a...P.
210 0020 ff ff 18 00 ff ff 00 00 02 00 ff ff ff ff 04 00 ........ ........
211 0030 ff ff ff ff ff ff ff ff 0a 00 25 00 27 00 ff ff ........ ..%.'...
212 0040 29 00 ff ff ff ff 2b 00 ff ff 2d 00 ff ff ff ff ).....+. ..-.....
213 0050 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
214 0060 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
215 0070 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
216 0080 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
217 0090 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
218 00a0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
219 00b0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
220 00c0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
221 00d0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
222 00e0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
223 00f0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
224 0100 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
225 0110 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
226 0120 ff ff ff ff ff ff 2f 00 07 00 0d 00 1a 24 3c 31 ....../. .....$<1
227 0130 3e 00 1b 3d 25 70 31 25 7b 33 32 7d 25 2b 25 63 >..=%p1% {32}%+%c
228 0140 25 70 32 25 7b 33 32 7d 25 2b 25 63 00 0a 00 1e %p2%{32} %+%c....
229 0150 00 08 00 0c 00 0b 00 0a 00 ........ .
230
233 Some limitations:
234 · total compiled entries cannot exceed 4096 bytes in the legacy for‐
236 mat.
237 · total compiled entries cannot exceed 32768 bytes in the extended
239 format.
240 · the name field cannot exceed 128 bytes.
242
244 /usr/share/terminfo/*/* compiled terminal capability data base
245
247 curses(3X), terminfo(5).
248
250 Thomas E. Dickey
251 extended terminfo format for ncurses 5.0
252 hashed database support for ncurses 5.6
253 extended number support for ncurses 6.1
254 Eric S. Raymond
256 documented legacy terminfo format, e.g., from pcurses.
257 term(5)