# tput 1 2024-01-13 ncurses 6.4 User commands

    tput(1)                          User commands                         tput(1)

## NAME

           tput,  init,  reset - initialize a terminal, exercise its capabilities,
           or query terminfo database

## SYNOPSIS

           tput [-T terminal-type] {cap-code [parameter ...]} ...

           tput [-T terminal-type] [-x] clear

           tput [-T terminal-type] init

           tput [-T terminal-type] reset

           tput [-T terminal-type] longname

           tput -S

           tput -V

## DESCRIPTION

           tput uses the terminfo library and database to  make  terminal-specific
           capabilities  and  information available to the shell, to initialize or
           reset the terminal, or to report  a  description  of  the  current  (or
           specified)  terminal  type.  Terminal capabilities are accessed by cap-
           code.

           terminfo(5) discusses terminal capabilities at length  and  presents  a
           complete list of cap-codes.

           When   retrieving  capability  values,  the  result  depends  upon  the
           capability's type.

           Boolean  tput sets its exit status to 0 if the terminal possesses  cap-
                    code, and 1 if it does not.

           numeric  tput  writes  cap-code's  decimal value to the standard output
                    stream if defined (-1 if it is not) followed by a newline.

           string   tput writes cap-code's value to the standard output stream  if
                    defined, without a trailing newline.

           Before  using  a value returned on the standard output, the application
           should test tput's exit status to be sure it is 0;  see  section  "EXIT
           STATUS" below.

### Operands

           Generally,  an  operand  is  a  cap-code,  a  capability  code from the
           terminal database, or a parameter thereto.  Three others are  specially
           recognized by tput: init, reset, and longname.  Although these resemble
           capability codes, they in fact receive special handling; we  term  them
           "pseudo-capabilities".

           cap-code   indicates a capability from the terminal database.

                      If  the  capability  is of string type and takes parameters,
                      the arguments following the capability will be used  as  its
                      parameters.

                      Most   parameters   are   numeric.    Only  a  few  terminal
                      capabilities require string parameters; tput uses a table to
                      decide  which  to  pass  as  strings.   Normally  tput  uses
                      tparm(3x) to perform the substitution.  If no parameters are
                      given  for  the  capability,  tput writes the string without
                      performing the substitution.

           init       initializes the  terminal.   If  the  terminal  database  is
                      present  and  an  entry for the user's terminal type exists,
                      the following occur.

                      (1)  tput  retrieves  the  terminal's  mode  settings.    It
                           successively  tests  the file descriptors corresponding
                           to

                           o   the standard error stream,

                           o   the standard output stream,

                           o   the standard input stream, and

                           o   /dev/tty

                           to obtain terminal settings.   Having  retrieved  them,
                           tput  remembers  which  descriptor  to  use for further
                           updates.

                      (2)  If the terminal dimensions cannot be obtained from  the
                           operating  system, but the environment or terminal type
                           database  entry  describes  them,  tput   updates   the
                           operating system's notion of them.

                      (3)  tput updates the terminal modes.

                           o   Any  delays  specified  in  the entry (for example,
                               when a newline is sent) are  set  in  the  terminal
                               driver.

                           o   Tab   expansion   is  turned  on  or  off  per  the
                               specification in the entry, and

                           o   if tabs are not expanded, standard  tabs  (every  8
                               spaces) are set.

                      (4)  If  initialization capabilities, detailed in subsection
                           "Tabs and Initialization" of terminfo(5), are  present,
                           tput writes them to the standard output stream.

                      (5)  tput flushes the standard output stream.

                      If  an  entry  lacks  the information needed for an activity
                      above, that activity is silently skipped.

           reset      re-initializes  the  terminal.    A   reset   differs   from
                      initialization in two ways.

                      (1)  tput sets the the terminal modes to a "sane" state,

                           o   enabling cooked and echo modes,

                           o   disabling cbreak and raw modes,

                           o   enabling newline translation, and

                           o   setting  any  unset  special  characters  to  their
                               default values.

                      (2)  If any reset capabilities are defined for the  terminal
                           type,   tput   writes   them   to  the  output  stream.
                           Otherwise,  tput  uses   any   defined   initialization
                           capabilities.    Reset  capabilities  are  detailed  in
                           subsection "Tabs and Initialization" of terminfo(5).

           longname   A terminfo entry begins with one or more names by  which  an
                      application  can  refer  to  the  entry,  before the list of
                      terminal capabilities.   The  names  are  separated  by  "|"
                      characters.   X/Open  Curses  terms  the last name the "long
                      name", and indicates that it may include blanks.

                      tic warns if the last  name  does  not  include  blanks,  to
                      accommodate  old terminfo entries that treated the long name
                      as an optional feature.  The long name is often referred  to
                      as the description field.

                      If  the  terminal  database  is present and an entry for the
                      user's terminal type exists, tput reports its description to
                      the standard output stream, without a trailing newline.  See
                      terminfo(5).

           Note: Redirecting the output of "tput init" or "tput reset" to  a  file
           will capture only part of their actions.  Changes to the terminal modes
           are not affected by file descriptor  redirection,  since  the  terminal
           modes are altered via ioctl(2).

### Aliases

           If  tput  is  invoked  via  link  with any of the names clear, init, or
           reset, it operates as if run with the corresponding (pseudo-)capability
           operand.  For example, executing a link named reset that points to tput
           has the same effect as "tput reset".  (The tset(1) utility also  treats
           a link named reset specially.)

           If  tput  is  invoked by a link named init, this has the same effect as
           "tput init".  Such a link is seldom employed because another program of
           that name is in widespread use.

### Terminal Size

           Besides  the  pseudo-capabilities (such as init), tput treats the lines
           and cols cap-codes specially: it may call setupterm(3x) to  obtain  the
           terminal size.

           o   First, tput attempts to obtain these capabilities from the terminal
               database.  This generally fails for terminal emulators, which  lack
               a fixed window size and thus omit the capabilities.

           o   It  then  asks  the operating system for the terminal's size, which
               generally works, unless the connection is via a  serial  line  that
               does not support "NAWS": negotiations about window size.

           o   Finally,  it  inspects the environment variables LINES and COLUMNS,
               which may override the terminal size.

           If the -T option is given, tput ignores the  environment  variables  by
           calling  use_tioctl(TRUE),  relying  upon  the  operating  system  (or,
           ultimately, the terminal database).

## OPTIONS

           -S       retrieves more than one capability  per  invocation  of  tput.
                    The  capabilities  must  be  passed  to tput from the standard
                    input stream instead of from the  command  line  (see  section
                    "EXAMPLES"  below).   Only  one  cap-code is allowed per line.
                    The -S option changes  the  meanings  of  the  0  and  1  exit
                    statuses (see section "EXIT STATUS" below).

                    Some  capabilities  use  string parameters rather than numeric
                    ones.  tput employs a  built-in  table  and  the  presence  of
                    parameters  in  its input to decide how to interpret them, and
                    whether to use tparm(3x).

           -T type  indicates  the  terminal's  type.   Normally  this  option  is
                    unnecessary,   because  a  default  is  taken  from  the  TERM
                    environment variable.  If specified, the environment variables
                    LINES and COLUMNS are also ignored.

           -V       reports the version of ncurses associated with tput, and exits
                    with a successful status.

           -x       prevents "tput clear" from attempting to clear the  scrollback
                    buffer.

## EXIT STATUS

           Normally, one should interpret tput's exit statuses as follows.

           Status   Meaning When -S Not Specified
           ------------------------------------------------------------------------
           0        Boolean or string capability present
           1        Boolean or numeric capability absent
           2        usage error or no terminal type specified
           3        unrecognized terminal type
           4        unrecognized capability code
           >4       system error (4 + errno)

           When the -S option is used, some statuses change meanings.

           Status   Meaning When -S Specified
           ------------------------------------------------------------------------
           0        all operands interpreted
           1        unused
           4        some operands not interpreted

## ENVIRONMENT

           tput command reads one environment variable.

           TERM    denotes  the  terminal  type.   Each terminal type is distinct,
                   though many are similar.  The -T option overrides its value.

## FILES

           /usr/share/tabset
                  tab stop initialization database

           /usr/share/terminfo
                  compiled terminal description database

## PORTABILITY

           Over time ncurses tput has  differed  from  that  of  System V  in  two
           important respects, one now mostly historical.

           o   "tput  cap-code" writes to the standard output, which need not be a
               terminal device.  However, the operands  that  manipulate  terminal
               modes might not use the standard output.

               System V  tput's  init  and  reset  operands use logic from 4.1cBSD
               tset,  manipulating  terminal  modes.   It  checks  the  same  file
               descriptors  (and  /dev/tty) for association with a terminal device
               as ncurses now does, and if none are, finally assumes a  1200  baud
               terminal.  When updating terminal modes, it ignores errors.

               Until  ncurses  6.1  (see  section  "HISTORY"  below), tput did not
               modify  terminal  modes.   It  now  employs  a  scheme  similar  to
               System V, using functions shared with tset (and ultimately based on
               4.4BSD tset).  If it is not able to open a terminal (for  instance,
               when run by cron(1)), tput exits with an error status.

           o   System V  tput  assumes  that  the  type  of  a cap-code operand is
               numeric if all the characters of its value are decimal numbers;  if
               they are not, it treats cap-code as a string capability.

               Most implementations that provide support for cap-code operands use
               the tparm(3x) function to expand  its  parameters.   That  function
               expects  a mixture of numeric and string parameters, requiring tput
               to know which type to use.

               ncurses tput uses a table to determine the parameter types for  the
               standard  cap-code  operands,  and  an internal function to analyze
               nonstandard cap-code operands.

               While more reliable than System V's utility, a portability  problem
               is  introduced  by this analysis.  An OpenBSD developer adapted the
               internal library function from ncurses to  port  NetBSD's  termcap-
               based  tput to terminfo, and modified it to interpret multiple cap-
               codes (and parameters) on the command line.  Portable  applications
               should  not  rely  upon  this feature; ncurses offers it to support
               applications written specifically for OpenBSD.

           This implementation, unlike others, accepts both termcap  and  terminfo
           cap-codes  if  termcap  support is compiled in.  In that case, however,
           the predefined termcap and terminfo codes have two ambiguities; ncurses
           assumes the terminfo code.

           o   The  cap-code  dl means delete_line to termcap but parm_delete_line
               to terminfo.  termcap uses the code DL for parm_delete_line.  term-
               info uses the code dch1 for delete_line.

           o   The  cap-code  ed  means exit_delete_mode to termcap but clr_eos to
               terminfo.  termcap uses the code cd for clr_eos.  terminfo uses the
               code rmdc for exit_delete_mode.

           The   longname  operand,  -S  option,  and  the  parameter-substitution
           features used in the cup example below, were not supported in  AT&T/USL
           curses before SVr4 (1989).  Later, 4.3BSD-Reno (1990) added support for
           longname,  and  in  1994,  NetBSD  added  support  for  the  parameter-
           substitution features.

           IEEE   Std   1003.1/The   Open   Group   Base  Specifications  Issue  7
           (POSIX.1-2008) documents only the clear, init, and reset  operands.   A
           few observations of interest arise from that selection.

           o   ncurses supports clear as it does any other standard cap-code.  The
               others  (init  and  longname)  do  not   correspond   to   terminal
               capabilities.

           o   The  tput on SVr4-based systems such as Solaris, IRIX64, and HP-UX,
               as well as others such as AIX and Tru64, also support standard cap-
               code operands.

           o   A few platforms such as FreeBSD recognize termcap names rather than
               terminfo capability names in their respective tput commands.  Since
               2010,  NetBSD's  tput  uses  terminfo names.  Before that, it (like
               FreeBSD) recognized termcap names.

               Beginning in 2021, FreeBSD uses ncurses tput, configured  for  both
               terminfo (tested first) and termcap (as a fallback).

           Because (apparently) all certified Unix systems support the full set of
           capability codes, the reason for documenting only  a  few  may  not  be
           apparent.

           o   X/Open Curses Issue 7 documents tput differently, with cap-code and
               the other features used in this implementation.

           o   That is, there are two standards for tput:  POSIX  (a  subset)  and
               X/Open  Curses (the full implementation).  POSIX documents a subset
               to avoid the  complication  of  including  X/Open  Curses  and  the
               terminal capability database.

           o   While  it  is  certainly  possible  to write a tput program without
               using curses, no system with a  curses  implementation  provides  a
               tput utility that does not also support standard cap-codes.

           X/Open  Curses  Issue  7  (2009)  is  the  first  version  to  document
           utilities.  However that part of X/Open Curses does not follow existing
           practice (that is, System V curses behavior).

           o   It  assigns  exit status 4 to "invalid operand", which may have the
               same meaning as "unknown capability".   For  instance,  the  source
               code for Solaris xcurses uses the term "invalid" in this case.

           o   It  assigns  exit  status  255  to  a  numeric variable that is not
               specified in the terminfo database.  That likely is a documentation
               error,  mistaking  the  "-1"  written  to  the  standard  output to
               indicate  an  absent  or  cancelled  numeric  capability   for   an
               (unsigned) exit status.

           The various System V implementations (AIX, HP-UX, Solaris) use the same
           exit statuses as ncurses.

           NetBSD curses  documents  exit  statuses  that  correspond  to  neither
           ncurses nor X/Open Curses.

## HISTORY

           Bill  Joy  wrote  a  tput command during development of 4BSD in October
           1980.  This initial version only cleared the screen, and did  not  ship
           with official distributions.

           System V developed a different tput command.

           o   SVr2  (1984) provided a rudimentary tput that checked the parameter
               against each predefined capability and returned  the  corresponding
               value.    This   version   of   tput  did  not  use  tparm(3x)  for
               parameterized capabilities.

           o   SVr3 (1987) replaced that  with  a  more  extensive  program  whose
               support  for  init  and reset operands (more than half the program)
               incorporated the reset feature of BSD tset written by Eric Allman.

           o   SVr4 (1989) added color initialization  by  using  the  orig_colors
               (oc) and orig_pair (op) capabilities in its init logic.

           Keith  Bostic  refactored BSD tput for shipment in 4.3BSD-Tahoe (1988),
           then replaced it the next year  with  a  new  implementation  based  on
           System V  tput.   Bostic's  version  similarly accepted some parameters
           named for terminfo (pseudo-)capabilities: clear,  init,  longname,  and
           reset.   However,  because  he  had only termcap available, it accepted
           termcap names for other capabilities.  Also, Bostic's BSD tput did  not
           modify the terminal modes as the earlier BSD tset had done.

           At  the  same time, Bostic added a shell script named "clear" that used
           tput to clear the screen.  Both of these appeared in  4.4BSD,  becoming
           the "modern" BSD implementation of tput.

           The  origin of ncurses tput lies outside both System V and BSD, in Ross
           Ridge's mytinfo package, published  on  comp.sources.unix  in  December
           1992.   Ridge's  program  made  more  sophisticated use of the terminal
           capabilities than the BSD program.  Eric Raymond used that tput program
           (and  other  parts  of mytinfo) in ncurses in June 1995.  Incorporating
           the portions dealing with terminal capabilities almost without  change,
           Raymond  made  improvements  to  the  way  command-line parameters were
           handled.

           Before ncurses 6.1 (2018), its tset and tput utilities differed.

           o   tset was more effective, resetting the terminal modes  and  special
               characters.

           o   On  the  other hand, tset's repertoire of terminal capabilities for
               resetting the terminal was more limited; it had only equivalents of
               reset_1string  (rs1), reset_2string (rs2), and reset_file (rf), and
               not the tab stop and margin update features of tput.

           The reset program is traditionally an alias for tset due to its ability
           to reset terminal modes and special characters.

           As  of  ncurses  6.1,  the  "reset"  features  of  the two programs are
           (mostly) the same.  Two minor differences remain.

           o   The tset program waits one  second  when  resetting,  in  case  the
               terminal happens to be a hardware device.

           o   The  two  programs  write  the  terminal  initialization strings to
               different streams; that is, standard error for  tset  and  standard
               output for tput.

## EXAMPLES

           tput init
                  Initialize the terminal according to the type of terminal in the
                  TERM environment variable.  If  the  system  does  not  reliably
                  initialize the terminal upon login, this command can be included
                  in $HOME/.profile after exporting the TERM environment variable.

           tput -T5620 reset
                  Reset an AT&T 5620 terminal, overriding the terminal type in the
                  TERM environment variable.

           tput cnorm
                  Set cursor to normal visibility.

           tput home
                  Move the cursor to row 0, column 0: the upper left corner of the
                  screen, usually known as the "home" cursor position.

           tput clear
                  Clear the screen: write the clear_screen capability's  value  to
                  the standard output stream.

           tput cols
                  Report the number of columns used by the current terminal type.

           tput -Tadm3a cols
                  Report the number of columns used by an ADM-3A terminal.

           strong=`tput smso` normal=`tput rmso`
                  Set  shell variables to capability values: strong and normal, to
                  begin and end, respectively, stand-out mode  for  the  terminal.
                  One might use these to present a prompt.

                         printf "${strong}Username:${normal} "

           tput hc
                  Indicate  via  exit  status  whether the terminal is a hard copy
                  device.

           tput cup 23 4
                  Move the cursor to row 23, column 4.

           tput cup
                  Report the value of the cursor_address  (cup)  capability  (used
                  for cursor movement), with no parameters substituted.

           tput longname
                  Report  the terminfo database's description of the terminal type
                  specified in the TERM environment variable.

           tput -S
                  Process multiple capabilities.  The -S option can be  profitably
                  used with a shell "here document".

                  $ tput -S <<!
                  > clear
                  > cup 10 10
                  > bold
                  > !

                  The  foregoing  clears  the screen, moves the cursor to position
                  (10, 10) and turns on bold (extra bright) mode.

           tput clear cup 10 10 bold
                  Perform the same actions as the foregoing "tput -S" example.

## SEE ALSO

           clear(1), stty(1), tabs(1), tset(1), curs_termcap(3x), terminfo(5)

    ncurses 6.4                       2024-01-13                           tput(1)