term(7) Miscellaneous term(7) #

term(7) Miscellaneous term(7)

NNAAMMEE #

 term - conventions for naming terminal types

DDEESSCCRRIIPPTTIIOONN #

 The environment variable TTEERRMM should normally contain the type name of
 the terminal, console or display-device type you are using.  This
 information is critical for all screen-oriented programs, including your
 editor and mailer.

 A default TTEERRMM value will be set on a per-line basis by either
 //eettcc//iinniittttaabb (e.g., System-V-like UNIXes) or //eettcc//ttttyyss (BSD UNIXes).
 This will nearly always suffice for workstation and microcomputer
 consoles.

 If you use a dialup line, the type of device attached to it may vary.
 Older UNIX systems pre-set a very dumb terminal type like “dumb” or
 “dialup” on dialup lines.  Newer ones may pre-set “vt100”, reflecting the
 prevalence of DEC VT100-compatible terminals and personal-computer
 emulators.

 Modern telnets pass your TTEERRMM environment variable from the local side to
 the remote one.  There can be problems if the remote terminfo or termcap
 entry for your type is not compatible with yours, but this situation is
 rare and can almost always be avoided by explicitly exporting “vt100”
 (assuming you are in fact using a VT100-superset console, terminal, or
 terminal emulator).

 In any case, you are free to override the system TTEERRMM setting to your
 taste in your shell profile.  The ttsseett(1) utility may be of assistance;
 you can give it a set of rules for deducing or requesting a terminal type
 based on the tty device and baud rate.

 Setting your own TTEERRMM value may also be useful if you have created a
 custom entry incorporating options (such as visual bell or reverse-video)
 which you wish to override the system default type for your line.

 Terminal type descriptions are stored as files of capability data
 underneath /usr/share/terminfo.  To browse a list of all terminal names
 recognized by the system, do

         toe | more

 from your shell.  These capability files are in a binary format optimized
 for retrieval speed (unlike the old text-based tteerrmmccaapp format they
 replace); to examine an entry, you must use the iinnffooccmmpp(1) command.
 Invoke it as follows:

         infocmp _e_n_t_r_y___n_a_m_e

 where _e_n_t_r_y___n_a_m_e is the name of the type you wish to examine (and the
 name of its capability file the subdirectory of /usr/share/terminfo named
 for its first letter).  This command dumps a capability file in the text
 format described by tteerrmmiinnffoo(5).

 The first line of a tteerrmmiinnffoo(5) description gives the names by which
 terminfo knows a terminal, separated by “|” (pipe-bar) characters with
 the last name field terminated by a comma.  The first name field is the
 type's _p_r_i_m_a_r_y _n_a_m_e, and is the one to use when setting TTEERRMM.  The last
 name field (if distinct from the first) is actually a description of the
 terminal type (it may contain blanks; the others must be single words).
 Name fields between the first and last (if present) are aliases for the
 terminal, usually historical names retained for compatibility.

 There are some conventions for how to choose terminal primary names that
 help keep them informative and unique.  Here is a step-by-step guide to
 naming terminals that also explains how to parse them:

 First, choose a root name.  The root will consist of a lower-case letter
 followed by up to seven lower-case letters or digits.  You need to avoid
 using punctuation characters in root names, because they are used and
 interpreted as filenames and shell meta-characters (such as !, $, *, ?,
 etc.) embedded in them may cause odd and unhelpful behavior.  The slash
 (/), or any other character that may be interpreted by anyone's file
 system (\, $, [, ]), is especially dangerous (terminfo is platform-
 independent, and choosing names with special characters could someday
 make life difficult for users of a future port).  The dot (.) character
 is relatively safe as long as there is at most one per root name; some
 historical terminfo names use it.

 The root name for a terminal or workstation console type should almost
 always begin with a vendor prefix (such as hhpp for Hewlett-Packard, wwyy for
 Wyse, or aatttt for AT&T terminals), or a common name of the terminal line
 (vvtt for the VT series of terminals from DEC, or ssuunn for Sun Microsystems
 workstation consoles, or rreeggeenntt for the ADDS Regent series.  You can list
 the terminfo tree to see what prefixes are already in common use.  The
 root name prefix should be followed when appropriate by a model number;
 thus vvtt110000, hhpp22662211, wwyy5500.

 The root name for a PC-Unix console type should be the OS name, i.e.,
 lliinnuuxx, bbssddooss, ffrreeeebbssdd, nneettbbssdd.  It should _n_o_t be ccoonnssoollee or any other
 generic that might cause confusion in a multi-platform environment!  If a
 model number follows, it should indicate either the OS release level or
 the console driver release level.

 The root name for a terminal emulator (assuming it does not fit one of
 the standard ANSI or vt100 types) should be the program name or a readily
 recognizable abbreviation of it (i.e., vveerrssaatteerrmm, ccttrrmm).

 Following the root name, you may add any reasonable number of hyphen-
 separated feature suffixes.

 2p   Has two pages of memory.  Likewise 4p, 8p, etc.

 mc   Magic-cookie.  Some terminals (notably older Wyses) can only support
      one attribute without magic-cookie lossage.  Their base entry is
      usually paired with another that has this suffix and uses magic
      cookies to support multiple attributes.

 -am  Enable auto-margin (right-margin wraparound).

 -m   Mono mode - suppress color support.

 -na  No arrow keys - termcap ignores arrow keys which are actually there
      on the terminal, so the user can use the arrow keys locally.

 -nam No auto-margin - suppress am capability.

 -nl  No labels - suppress soft labels.

 -nsl No status line - suppress status line.

 -pp  Has a printer port which is used.

 -rv  Terminal in reverse video mode (black on white).

 -s   Enable status line.

 -vb  Use visible bell (flash) rather than beep.

 -w   Wide; terminal is in 132-column mode.

 Conventionally, if your terminal type is a variant intended to specify a
 line height, that suffix should go first.  So, for a hypothetical FuBarCo
 model 2317 terminal in 30-line mode with reverse video, best form would
 be ffuubbaarr--3300--rrvv (rather than, say, “fubar-rv-30”).

 Terminal types that are written not as standalone entries, but rather as
 components to be plugged into other entries via uussee capabilities, are
 distinguished by using embedded plus signs rather than dashes.

 Commands which use a terminal type to control display often accept a -T
 option that accepts a terminal name argument.  Such programs should fall
 back on the TTEERRMM environment variable when no -T option is specified.

PPOORRTTAABBIILLIITTYY #

 For maximum compatibility with older System V UNIXes, names and aliases
 should be unique within the first 14 characters.

FFIILLEESS #

 /usr/share/terminfo/?/*
      compiled terminal capability database

 /etc/inittab
      tty line initialization (AT&T-like UNIXes)

 /etc/ttys
      tty line initialization (BSD-like UNIXes)

SSEEEE AALLSSOO #

 ccuurrsseess(3), tteerrmmiinnffoo(5), tteerrmm(5).

ncurses 6.4 2023-07-01 term(7)