term(7)                          Miscellaneous Information Manual                         term(7)



NAME
       term - conventions for naming terminal types

DESCRIPTION
       The  environment variable TERM should normally contain the type name of the terminal, con‐
       sole 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., Sys‐
       tem-V-like UNIXes) or /etc/ttys (BSD UNIXes).  This will nearly always suffice  for  work‐
       station 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 compat‐
       ible 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 incorpo‐
       rating  options (such as visual bell or reverse-video) which you wish to override the sys‐
       tem default type for your line.

       Terminal type descriptions are stored as files of  capability  data  underneath  /etc/ter‐
       minfo.  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 capabil‐
       ity 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 ter‐
       minal, 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 set‐
       ting 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  his‐
       torical 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,  free‐
       bsd,  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 data base

       /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).



                                                                                          term(7)