term 7

term(7)                                                                term(7)


       term - conventions for naming terminal types


       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  con-

       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

       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 sit-
       uation is rare and can almost always be avoided by explicitly exporting
       "vt100"  (assuming you are in fact using a VT100-superset console, ter-
       minal, 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

       Terminal type descriptions are  stored  as  files  of  capability  data
       underneath  /usr/local/ncurses/lib/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  opti-
       mized  for  retrieval  speed  (unlike the old text-based termcap format
       they replace); to examine an entry, you must use the  infocmp(1m)  com-
       mand.  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/local/ncurses/lib/terminfo named for its first letter).  This com-
       mand dumps a capability file in  the  text  format  described  by  ter-

       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 compat-

       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 let-
       ter 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 plat-
       form-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 read-
       ily 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 sup-
            port 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  speci-


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


            compiled terminal capability data base

            tty line initialization (AT&T-like UNIXes)

            tty line initialization (BSD-like UNIXes)


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