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]
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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  System-V-like  UNIXes
23       and  systems using that convention, getty does this job by setting TERM
24       according to the type 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.
62
63       -e   Set the erase character to ch.
64
65       -I   Do not send the terminal or tab initialization strings to the ter‐
66            minal.
67
68       -i   Set the interrupt character to ch.
69
70       -k   Set the line kill character to ch.
71
72       -m   Specify a mapping from a port type to a terminal.  See the section
73            TERMINAL TYPE MAPPING for more information.
74
75       -Q   Do  not  display any values for the erase, interrupt and line kill
76            characters.  Normally tset displays the values for control charac‐
77            ters which differ from the system's default values.
78
79       -q   The  terminal  type  is  displayed to the standard output, and the
80            terminal is not initialized in any way.  The option `-' by  itself
81            is equivalent but archaic.
82
83       -r   Print the terminal type to the standard error output.
84
85       -s   Print the sequence of shell commands to initialize the environment
86            variable TERM to the standard output.  See the section SETTING THE
87            ENVIRONMENT for details.
88
89       -V   reports the version of ncurses which was used in this program, and
90            exits.
91
92       -w   Resize the window to match the size deduced via  setupterm.   Nor‐
93            mally  this  has no effect, unless setupterm is not able to detect
94            the window size.
95
96       The arguments for the -e, -i, and -k options may either be  entered  as
97       actual  characters  or by using the `hat' notation, i.e., control-h may
98       be specified as ``^H'' or ``^h''.
99

SETTING THE ENVIRONMENT

101       It is often desirable to enter the terminal type and information  about
102       the terminal's capabilities into the shell's environment.  This is done
103       using the -s option.
104
105       When the -s option is specified, the commands to enter the  information
106       into  the  shell's  environment are written to the standard output.  If
107       the SHELL environmental variable ends in ``csh'', the commands are  for
108       csh,  otherwise, they are for sh.  Note, the csh commands set and unset
109       the shell variable noglob, leaving it unset.  The following line in the
110       .login or .profile files will initialize the environment correctly:
111
112           eval `tset -s options ... `
113

TERMINAL TYPE MAPPING

115       When the terminal is not hardwired into the system (or the current sys‐
116       tem information is  incorrect)  the  terminal  type  derived  from  the
117       /etc/ttys  file  or  the TERM environmental variable is often something
118       generic like network, dialup, or unknown.   When  tset  is  used  in  a
119       startup  script  it is often desirable to provide information about the
120       type of terminal used on such ports.
121
122       The purpose of the -m option is to map from some set of conditions to a
123       terminal type, that is, to tell tset ``If I'm on this port at a partic‐
124       ular speed, guess that I'm on that kind of terminal''.
125
126       The argument to the -m option consists of an  optional  port  type,  an
127       optional  operator,  an  optional  baud rate specification, an optional
128       colon (``:'') character and a terminal type.  The port type is a string
129       (delimited  by either the operator or the colon character).  The opera‐
130       tor may be any combination of ``>'', ``<'',  ``@'',  and  ``!'';  ``>''
131       means  greater  than,  ``<''  means less than, ``@'' means equal to and
132       ``!'' inverts the sense of the test.  The baud rate is specified  as  a
133       number  and  is  compared  with  the speed of the standard error output
134       (which should be the control terminal).  The terminal type is a string.
135
136       If the terminal type is not specified on the command line, the -m  map‐
137       pings are applied to the terminal type.  If the port type and baud rate
138       match the mapping, the terminal type specified in the mapping  replaces
139       the  current  type.   If  more than one mapping is specified, the first
140       applicable mapping is used.
141
142       For example, consider the following  mapping:  dialup>9600:vt100.   The
143       port type is dialup , the operator is >, the baud rate specification is
144       9600, and the terminal type is vt100.  The result of this mapping is to
145       specify  that  if  the  terminal  type  is dialup, and the baud rate is
146       greater than 9600 baud, a terminal type of vt100 will be used.
147
148       If no baud rate is specified, the terminal type  will  match  any  baud
149       rate.   If  no port type is specified, the terminal type will match any
150       port type.  For example, -m dialup:vt100  -m  :?xterm  will  cause  any
151       dialup port, regardless of baud rate, to match the terminal type vt100,
152       and any non-dialup port type to match the terminal type ?xterm.   Note,
153       because  of  the  leading  question mark, the user will be queried on a
154       default port as to whether they are actually using an xterm terminal.
155
156       No whitespace characters are  permitted  in  the  -m  option  argument.
157       Also,  to avoid problems with meta-characters, it is suggested that the
158       entire -m option argument be placed within single quote characters, and
159       that csh users insert a backslash character (``\'') before any exclama‐
160       tion marks (``!'').
161

HISTORY

163       The tset command appeared in BSD 3.0.  The ncurses  implementation  was
164       lightly  adapted  from the 4.4BSD sources for a terminfo environment by
165       Eric S. Raymond <esr@snark.thyrsus.com>.
166

COMPATIBILITY

168       The tset utility has been provided for backward-compatibility with  BSD
169       environments  (under  most modern UNIXes, /etc/inittab and getty(1) can
170       set TERM appropriately for each dial-up line; this  obviates  what  was
171       tset's  most  important  use).  This implementation behaves like 4.4BSD
172       tset, with a few exceptions specified here.
173
174       The -S option of BSD tset no longer works; it prints an  error  message
175       to  stderr  and dies.  The -s option only sets TERM, not TERMCAP.  Both
176       these changes are because the TERMCAP variable is no  longer  supported
177       under  terminfo-based  ncurses, which makes tset -S useless (we made it
178       die noisily rather than silently induce lossage).
179
180       There was an undocumented 4.4BSD feature that invoking tset via a  link
181       named  `TSET`  (or via any other name beginning with an upper-case let‐
182       ter) set the terminal to use upper-case only.  This  feature  has  been
183       omitted.
184
185       The -A, -E, -h, -u and -v options were deleted from the tset utility in
186       4.4BSD.  None of them were documented in 4.3BSD and all are of  limited
187       utility  at  best.   The -a, -d, and -p options are similarly not docu‐
188       mented or useful, but were retained as they appear to be in  widespread
189       use.   It is strongly recommended that any usage of these three options
190       be changed to use the -m option instead.  The -n  option  remains,  but
191       has  no effect.  The -adnp options are therefore omitted from the usage
192       summary above.
193
194       It is still permissible to specify the -e, -i, and -k  options  without
195       arguments, although it is strongly recommended that such usage be fixed
196       to explicitly specify the character.
197
198       As of 4.4BSD, executing tset as reset no longer implies the -Q  option.
199       Also, the interaction between the - option and the terminal argument in
200       some historic implementations of tset has been removed.
201

ENVIRONMENT

203       The tset command uses these environment variables:
204
205       SHELL
206            tells tset whether to initialize TERM using sh or csh syntax.
207
208       TERM Denotes your terminal  type.   Each  terminal  type  is  distinct,
209            though many are similar.
210
211       TERMCAP
212            may  denote  the  location of a termcap database.  If it is not an
213            absolute pathname, e.g., begins with a `/', tset removes the vari‐
214            able from the environment before looking for the terminal descrip‐
215            tion.
216

FILES

218       /etc/ttys
219            system port name to terminal type mapping database  (BSD  versions
220            only).
221
222       /usr/share/terminfo
223            terminal capability database
224

SEE ALSO

226       csh(1),   sh(1),   stty(1),   curs_terminfo(3X),  tty(4),  terminfo(5),
227       ttys(5), environ(7)
228
229       This describes ncurses version 5.9 (patch 20130511).
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233                                                                       tset(1)
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