term(7)                                                                                                                  term(7)



NAME
       term - conventions for naming terminal types

DESCRIPTION
       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 /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
       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
       /usr/share/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 ter-
       minal 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 (ter-
       minfo 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 appropri-
       ate 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
       For maximum compatibility with older System V UNIXes, names and aliases should be unique within the first 14 characters.

FILES
       /usr/share/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
       curses(3X), terminfo(5), term(5).



                                                                                                                         term(7)