1tset(1)                     General Commands Manual                    tset(1)
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NAME

6       tset, reset - terminal initialization
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SYNOPSIS

9       tset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal]
10       reset [-IQVcqrsw] [-] [-e ch] [-i ch] [-k ch] [-m mapping] [terminal]
11

DESCRIPTION

13       Tset initializes terminals.  Tset first determines the type of terminal
14       that you are using.  This determination is done as follows,  using  the
15       first terminal type found.
16
17       1. The terminal argument specified on the command line.
18
19       2. The value of the TERM environmental variable.
20
21       3.  (BSD  systems only.) The terminal type associated with the standard
22       error output device in the /etc/ttys file.  (On Linux and System-V-like
23       UNIXes,  getty  does  this  job  by  setting TERM according to the type
24       passed to it by /etc/inittab.)
25
26       4. The default terminal type, ``unknown''.
27
28       If the terminal type was not specified  on  the  command-line,  the  -m
29       option mappings are then applied (see the section TERMINAL TYPE MAPPING
30       for more information).  Then, if the terminal type begins with a  ques‐
31       tion  mark (``?''), the user is prompted for confirmation of the termi‐
32       nal type.  An empty response confirms the type, or, another type can be
33       entered  to specify a new type.  Once the terminal type has been deter‐
34       mined, the terminfo entry for the terminal is retrieved.   If  no  ter‐
35       minfo  entry  is  found  for the type, the user is prompted for another
36       terminal type.
37
38       Once the terminfo entry  is  retrieved,  the  window  size,  backspace,
39       interrupt  and  line  kill characters (among many other things) are set
40       and the terminal and tab initialization strings are sent to  the  stan‐
41       dard  error  output.   Finally,  if  the erase, interrupt and line kill
42       characters have changed, or are not set to their default values,  their
43       values  are  displayed  to the standard error output.  Use the -c or -w
44       option to select only the window sizing versus  the  other  initializa‐
45       tion.  If neither option is given, both are assumed.
46
47       When  invoked  as  reset,  tset  sets  cooked and echo modes, turns off
48       cbreak and raw modes, turns on newline translation and resets any unset
49       special  characters  to  their default values before doing the terminal
50       initialization described above.  This is useful after  a  program  dies
51       leaving a terminal in an abnormal state.  Note, you may have to type
52
53           <LF>reset<LF>
54
55       (the  line-feed character is normally control-J) to get the terminal to
56       work, as carriage-return may no longer  work  in  the  abnormal  state.
57       Also, the terminal will often not echo the command.
58
59       The options are as follows:
60
61       -c   Set  control  characters and modes.  -e Set the erase character to
62            ch.
63
64       -I   Do not send the terminal or tab initialization strings to the ter‐
65            minal.
66
67       -i   Set the interrupt character to ch.
68
69       -k   Set the line kill character to ch.
70
71       -m   Specify a mapping from a port type to a terminal.  See the section
72            TERMINAL TYPE MAPPING for more information.
73
74       -Q   Do not display any values for the erase, interrupt and  line  kill
75            characters.  Normally tset displays the values for control charac‐
76            ters which differ from the system's default values.
77
78       -q   The terminal type is displayed to the  standard  output,  and  the
79            terminal  is not initialized in any way.  The option `-' by itself
80            is equivalent but archaic.
81
82       -r   Print the terminal type to the standard error output.
83
84       -s   Print the sequence of shell commands to initialize the environment
85            variable TERM to the standard output.  See the section SETTING THE
86            ENVIRONMENT for details.
87
88       -V   reports the version of ncurses which was used in this program, and
89            exits.
90
91       -w   Resize  the  window to match the size deduced via setupterm.  Nor‐
92            mally this has no effect, unless setupterm is not able  to  detect
93            the window size.
94
95       The  arguments  for the -e, -i, and -k options may either be entered as
96       actual characters or by using the `hat' notation, i.e. control-h may be
97       specified as ``^H'' or ``^h''.
98

SETTING THE ENVIRONMENT

100       It  is often desirable to enter the terminal type and information about
101       the terminal's capabilities into the shell's environment.  This is done
102       using the -s option.
103
104       When  the -s option is specified, the commands to enter the information
105       into the shell's environment are written to the  standard  output.   If
106       the  SHELL environmental variable ends in ``csh'', the commands are for
107       csh, otherwise, they are for sh.  Note, the csh commands set and  unset
108       the shell variable noglob, leaving it unset.  The following line in the
109       .login or .profile files will initialize the environment correctly:
110
111           eval `tset -s options ... `
112

TERMINAL TYPE MAPPING

114       When the terminal is not hardwired into the system (or the current sys‐
115       tem  information  is  incorrect)  the  terminal  type  derived from the
116       /etc/ttys file or the TERM environmental variable  is  often  something
117       generic  like  network,  dialup,  or  unknown.   When tset is used in a
118       startup script it is often desirable to provide information  about  the
119       type of terminal used on such ports.
120
121       The purpose of the -m option is to map from some set of conditions to a
122       terminal type, that is, to tell tset ``If I'm on this port at a partic‐
123       ular speed, guess that I'm on that kind of terminal''.
124
125       The  argument  to  the  -m option consists of an optional port type, an
126       optional operator, an optional baud  rate  specification,  an  optional
127       colon (``:'') character and a terminal type.  The port type is a string
128       (delimited by either the operator or the colon character).  The  opera‐
129       tor  may  be  any  combination of ``>'', ``<'', ``@'', and ``!''; ``>''
130       means greater than, ``<'' means less than, ``@''  means  equal  to  and
131       ``!''  inverts  the sense of the test.  The baud rate is specified as a
132       number and is compared with the speed  of  the  standard  error  output
133       (which should be the control terminal).  The terminal type is a string.
134
135       If  the terminal type is not specified on the command line, the -m map‐
136       pings are applied to the terminal type.  If the port type and baud rate
137       match  the mapping, the terminal type specified in the mapping replaces
138       the current type.  If more than one mapping  is  specified,  the  first
139       applicable mapping is used.
140
141       For  example,  consider  the following mapping: dialup>9600:vt100.  The
142       port type is dialup , the operator is >, the baud rate specification is
143       9600, and the terminal type is vt100.  The result of this mapping is to
144       specify that if the terminal type is  dialup,  and  the  baud  rate  is
145       greater than 9600 baud, a terminal type of vt100 will be used.
146
147       If  no  baud  rate  is specified, the terminal type will match any baud
148       rate.  If no port type is specified, the terminal type will  match  any
149       port  type.   For  example,  -m  dialup:vt100 -m :?xterm will cause any
150       dialup port, regardless of baud rate, to match the terminal type vt100,
151       and  any non-dialup port type to match the terminal type ?xterm.  Note,
152       because of the leading question mark, the user will  be  queried  on  a
153       default port as to whether they are actually using an xterm terminal.
154
155       No  whitespace  characters  are  permitted  in  the -m option argument.
156       Also, to avoid problems with meta-characters, it is suggested that  the
157       entire -m option argument be placed within single quote characters, and
158       that csh users insert a backslash character (``\'') before any exclama‐
159       tion marks (``!'').
160

HISTORY

162       The  tset  command appeared in BSD 3.0.  The ncurses implementation was
163       lightly adapted from the 4.4BSD sources for a terminfo  environment  by
164       Eric S. Raymond <esr@snark.thyrsus.com>.
165

COMPATIBILITY

167       The  tset utility has been provided for backward-compatibility with BSD
168       environments (under most modern UNIXes, /etc/inittab and  getty(1)  can
169       set  TERM  appropriately  for each dial-up line; this obviates what was
170       tset's most important use).  This implementation  behaves  like  4.4BSD
171       tset, with a few exceptions specified here.
172
173       The  -S  option of BSD tset no longer works; it prints an error message
174       to stderr and dies.  The -s option only sets TERM, not  TERMCAP.   Both
175       these  changes  are because the TERMCAP variable is no longer supported
176       under terminfo-based ncurses, which makes tset -S useless (we  made  it
177       die noisily rather than silently induce lossage).
178
179       There  was an undocumented 4.4BSD feature that invoking tset via a link
180       named `TSET` (or via any other name beginning with an  upper-case  let‐
181       ter)  set  the  terminal to use upper-case only.  This feature has been
182       omitted.
183
184       The -A, -E, -h, -u and -v options were deleted from the tset utility in
185       4.4BSD.   None of them were documented in 4.3BSD and all are of limited
186       utility at best.  The -a, -d, and -p options are  similarly  not  docu‐
187       mented  or useful, but were retained as they appear to be in widespread
188       use.  It is strongly recommended that any usage of these three  options
189       be  changed  to  use the -m option instead.  The -n option remains, but
190       has no effect.  The -adnp options are therefore omitted from the  usage
191       summary above.
192
193       It  is  still permissible to specify the -e, -i, and -k options without
194       arguments, although it is strongly recommended that such usage be fixed
195       to explicitly specify the character.
196
197       As  of 4.4BSD, executing tset as reset no longer implies the -Q option.
198       Also, the interaction between the - option and the terminal argument in
199       some historic implementations of tset has been removed.
200

ENVIRONMENT

202       The tset command uses these environment variables:
203
204       SHELL
205            tells tset whether to initialize TERM using sh or csh syntax.
206
207       TERM Denotes  your  terminal  type.   Each  terminal  type is distinct,
208            though many are similar.
209
210       TERMCAP
211            may denote the location of a termcap database.  If it  is  not  an
212            absolute pathname, e.g., begins with a `/', tset removes the vari‐
213            able from the environment before looking for the terminal descrip‐
214            tion.
215

FILES

217       /etc/ttys
218            system  port  name to terminal type mapping database (BSD versions
219            only).
220
221       /usr/share/terminfo
222            terminal capability database
223

SEE ALSO

225       csh(1),  sh(1),  stty(1),   curs_terminfo(3X),   tty(4),   terminfo(5),
226       ttys(5), environ(7)
227
228       This describes ncurses version 5.6 (patch 20070812).
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232                                                                       tset(1)
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