term(7) — Linux manual page

NAME | DESCRIPTION | PORTABILITY | FILES | SEE ALSO | COLOPHON

term(7)             Miscellaneous Information Manual             term(7)

NAME         top

       term - conventions for naming terminal types

DESCRIPTION         top

       The environment variable TERM 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 TERM value will be set on a per-line basis by either
       /etc/inittab (e.g., System-V-like UNIXes) or /etc/ttys (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 TERM 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 TERM setting to
       your taste in your shell profile.  The @TSET@(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 TERM 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 @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 termcap
       format they replace); to examine an entry, you must use the
       @INFOCMP@(1M) command.  Invoke it as follows:

            @INFOCMP@ entry_name

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

       The first line of a terminfo(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 primary name, and is the one to
       use when setting TERM.  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 hp for Hewlett-
       Packard, wy for Wyse, or att for AT&T terminals), or a common
       name of the terminal line (vt for the VT series of terminals from
       DEC, or sun for Sun Microsystems workstation consoles, or regent
       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 vt100, hp2621, wy50.

       The root name for a PC-Unix console type should be the OS name,
       i.e., linux, bsdos, freebsd, netbsd.  It should not be console 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.,
       versaterm, ctrm).

       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 fubar-30-rv (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 use
       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 TERM environment variable when
       no -T option is specified.

PORTABILITY         top

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

FILES         top

       @TERMINFO@/?/*
            compiled terminal capability data base

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

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

SEE ALSO         top

       curses(3X), terminfo(5), term(5).

COLOPHON         top

       This page is part of the ncurses (new curses) project.
       Information about the project can be found at 
       ⟨https://www.gnu.org/software/ncurses/ncurses.html⟩.  If you have
       a bug report for this manual page, send it to
       bug-ncurses-request@gnu.org.  This page was obtained from the
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       ⟨git://ncurses.scripts.mit.edu/ncurses.git⟩ on 2021-06-20.  (At
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       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

                                                                 term(7)

Pages that refer to this page: terminfo(5)