X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fterm.5;h=b876fea1b2ced9f3f0803b95ea954ea75917e359;hp=d4519dffe1b86ac5fa7a6d887af0d53413b3175b;hb=97cb42f22c43eb31a4bf11475bd73ab0e0b10923;hpb=1501ae2a13db0ffd2db8404c24aa5010a88ea91b diff --git a/man/term.5 b/man/term.5 index d4519dff..b876fea1 100644 --- a/man/term.5 +++ b/man/term.5 @@ -1,5 +1,5 @@ .\"*************************************************************************** -.\" Copyright (c) 1998-2016,2017 Free Software Foundation, Inc. * +.\" Copyright (c) 1998-2018,2019 Free Software Foundation, Inc. * .\" * .\" Permission is hereby granted, free of charge, to any person obtaining a * .\" copy of this software and associated documentation files (the * @@ -26,7 +26,7 @@ .\" authorization. * .\"*************************************************************************** .\" -.\" $Id: term.5,v 1.27 2017/12/16 21:27:20 tom Exp $ +.\" $Id: term.5,v 1.32 2019/01/12 23:11:08 tom Exp $ .TH term 5 .ie \n(.g .ds `` \(lq .el .ds `` `` @@ -43,7 +43,8 @@ .de NE .fi .ft R -.in -4 +.ie n .in -4 +.el .in -2 .. .de bP .ie n .IP \(bu 4 @@ -58,7 +59,7 @@ term \- format of compiled term file. .SH DESCRIPTION .SS STORAGE LOCATION Compiled terminfo descriptions are placed under the directory \fB\*d\fP. -Two configurations are supported (when building the ncurses libraries): +Two configurations are supported (when building the \fBncurses\fP libraries): .TP 5 .B directory tree A two-level scheme is used to avoid a linear search @@ -81,11 +82,11 @@ the terminfo's primary name as a key, and records containing only aliases pointing to the primary name. .IP If built to write hashed databases, -ncurses can still read terminfo databases organized as a directory tree, +\fBncurses\fP can still read terminfo databases organized as a directory tree, but cannot write entries into the directory tree. It can write (or rewrite) entries in the hashed database. .IP -ncurses distinguishes the two cases in the TERMINFO and TERMINFO_DIRS +\fBncurses\fP distinguishes the two cases in the TERMINFO and TERMINFO_DIRS environment variable by assuming a directory tree for entries that correspond to an existing directory, and hashed database otherwise. @@ -129,7 +130,8 @@ 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 +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 \s-1VAX\s+1 and \s-1PDP\s+1-11 (that is, little-endian machines). @@ -179,12 +181,15 @@ 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. .PP -The ncurses libraries and applications support extended terminfo binary format, -allowing users to define capabilities which are loaded at runtime. This +The \fBncurses\fP libraries and applications support +extended terminfo binary format, +allowing users to define capabilities which are loaded at runtime. +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, +\fBncurses\fP checks the size, +and if it exceeds that due to the predefined data, continues to parse according to its own scheme. .PP First, it reads the extended header (5 short integers): @@ -200,13 +205,17 @@ count of extended numeric capabilities count of extended string capabilities .TP 5 (4) -size of the extended string table in bytes. +count of the items in extended string table .TP 5 (5) -last offset of the extended string table in bytes. +size of the extended string table in bytes .RE .PP -Using the counts and sizes, ncurses allocates arrays and reads data +The count- and size-values for the extended string table +include the extended capability \fInames\fP as well as +extended capability \fIvalues\fP. +.PP +Using the counts and sizes, \fBncurses\fP allocates arrays and reads data for the extended capabilities in the same order as the header information. .PP The extended string table contains values for string capabilities. @@ -221,10 +230,10 @@ names with members of a \fBTERMTYPE\fP structure. .SS EXTENDED NUMBER FORMAT .PP On occasion, 16-bit signed integers are not large enough. -With ncurses 6.1, a new format is introduced by making a few changes +With \fBncurses\fP 6.1, a new format was introduced by making a few changes to the legacy format: .bP -a different magic number (0542) +a different magic number (octal 01036) .bP changing the type for the \fInumber\fP array from signed 16-bit integers to signed 32-bit integers. @@ -235,6 +244,8 @@ However, that cannot provide callers with the extended numbers. The library uses a similar but hidden data structure \fBTERMTYPE2\fP to provide data for the terminfo functions. .SH PORTABILITY +.SS setupterm +.PP Note that it is possible for .B setupterm to expect a different set of capabilities @@ -252,26 +263,54 @@ 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. +.SS Binary format +.PP +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. .PP 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 +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 \fBterminfo\fR(\*n) for detailed +System V and XSI Curses extensions. +See \fBterminfo\fR(\*n) for detailed discussion of terminfo source compatibility issues. .PP +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. +.SS Magic codes +.PP +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 \fBfile\fP 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 \fBscr_dump\fP(5)). +This implementation uses 01036 as a continuation of that sequence, +but with a different high-order byte to avoid confusion. +.SS The TERMTYPE structure +.PP Direct access to the \fBTERMTYPE\fP structure is provided for legacy applications. Portable applications should use the \fBtigetflag\fP and related functions described in \fBcurs_terminfo\fP(3X) for reading terminal capabilities. +.SS Mixed-case terminal names .PP 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 character\*('' of the terminal name used as +\fBncurses\fP represents the \*(``first character\*('' +of the terminal name used as the intermediate level of a directory tree in (two-character) hexadecimal form. .SH EXAMPLE As an example, here is a description for the Lear-Siegler