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tput 1 2024-06-08 ncurses 6.5 User commands

tput(1)                          User commands                         tput(1)




NAME

       tput - initialize a terminal, exercise its capabilities, or query term-
       info database


SYNOPSIS

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

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

       tput [-v] [-T terminal-type] init

       tput [-v] [-T terminal-type] reset

       tput [-v] [-T terminal-type] longname

       tput [-v] -S

       tput [-v] -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  cap-code  is  of  string type and takes parameters, tput
                  interprets arguments following cap-code as  the  parameters,
                  up to the (fixed) quantity the capability requires.

                  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".

       This feature was introduced by ncurses 5.2 in 2000.  It is rarely used:

       clear  is a separate program, which is both smaller and more frequently
              executed.

       init   has the same name as another program in widespread use.

       reset  is  provided  by  the  tset(1)  utility  (also  via a link named
              reset).


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       causes tput to operate verbosely, reporting warnings.

       -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 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 dl1 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 codes rather than
           terminfo capability codes in their respective tput commands.  Since
           2010, NetBSD's tput uses terminfo codes.   Before  that,  it  (like
           FreeBSD) recognized termcap codes.

           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  codes 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 line 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 line 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 6.5                       2024-06-08                           tput(1)