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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 (Linux and 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 preva-
       lence 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  prob-
       lems  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 subdirec-
       tory of /usr/share/terminfo named for its first letter).  This command dumps a capability file in the text for-
       mat 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 char-
       acters 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
       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)