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
       /etc/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(1) 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 /etc/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

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

FILES

       /etc/terminfo/?/*
            compiled terminal capability database

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

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

SEE ALSO

       ncurses(3NCURSES), terminfo(5), term(5).