# term 7 2025-08-16 ncurses 6.6 Miscellaneous

    term(7)                          Miscellaneous                         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  Unices) or /etc/ttys (BSD Unices).
           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 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.

## FILES

           /usr/share/terminfo
                  compiled terminal description database

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

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

## PORTABILITY

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

## SEE ALSO

           curses(3x), term(5), terminfo(5)

    ncurses 6.6                       2025-08-16                           term(7)