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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, console or	display-device type you	are using.   This  in-
       formation  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-
       soles.

       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 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 assist-
       ance; you can give it a set of rules for	deducing or requesting a  ter-
       minal 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  un-
       derneath	 /usr/share/misc/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/share/misc/ter-
       minfo  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 compat-
       ibility.

       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 Mi-
       crosystems workstation consoles,	or regent for the ADDS Regent  series.
       You can list the	terminfo tree to see what prefixes are already in com-
       mon 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-
       fied.

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

FILES
       /usr/share/misc/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)

NAME | DESCRIPTION | PORTABILITY | FILES | SEE ALSO

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