bionic (1) tput.1.gz

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NAME

       tput, reset - initialize a terminal or query terminfo database

SYNOPSIS

       tput [-Ttype] capname [parameters]
       tput [-Ttype] [-x] clear
       tput [-Ttype] init
       tput [-Ttype] reset
       tput [-Ttype] longname
       tput -S  <<
       tput -V

DESCRIPTION

       The  tput  utility  uses  the terminfo database to make the values of terminal-dependent capabilities and
       information available to the shell (see sh(1)), to initialize or reset the terminal, or return  the  long
       name of the requested terminal type.  The result depends upon the capability's type:

          string
               tput writes the string to the standard output.  No trailing newline is supplied.

          integer
               tput writes the decimal value to the standard output, with a trailing newline.

          boolean
               tput  simply sets the exit code (0 for TRUE if the terminal has the capability, 1 for FALSE if it
               does not), and writes nothing to the standard output.

       Before using a value returned on the standard output, the application should test the  exit  code  (e.g.,
       $?,  see  sh(1)) to be sure it is 0.  (See the EXIT CODES and DIAGNOSTICS sections.)  For a complete list
       of capabilities and the capname associated with each, see terminfo(5).

   Options
       -S     allows more than one capability per invocation of tput.  The capabilities must be passed  to  tput
              from  the  standard  input  instead  of  from the command line (see example).  Only one capname is
              allowed per line.  The -S option changes the meaning of the 0 and 1 boolean and string exit  codes
              (see the EXIT CODES section).

              Because some capabilities may use string parameters rather than numbers, tput uses a table and the
              presence of parameters in its input to decide whether to use tparm(3X), and how to  interpret  the
              parameters.

       -Ttype indicates the type of terminal.  Normally this option is unnecessary, because the default is taken
              from the environment variable TERM.  If -T is  specified,  then  the  shell  variables  LINES  and
              COLUMNS will also be ignored.

       -V     reports the version of ncurses which was used in this program, and exits.

       -x     do not attempt to clear the terminal's scrollback buffer using the extended “E3” capability.

   Commands
       A  few commands (init, reset and longname) are special; they are defined by the tput program.  The others
       are the names of capabilities from the terminal database (see terminfo(5) for a list).  Although init and
       reset resemble capability names, tput uses several capabilities to perform these special functions.

       capname
              indicates the capability from the terminal database.

              If  the  capability is a string that takes parameters, the arguments following the capability will
              be used as parameters for the string.

              Most parameters are numbers.  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   If  the  terminal  database  is  present  and an entry for the user's terminal exists (see -Ttype,
              above), the following will occur:

              (1)  first, tput retrieves the current terminal mode settings for your terminal.  It does this  by
                   successively testing

                   •   the standard error,

                   •   standard output,

                   •   standard input and

                   •   ultimately “/dev/tty”

                   to  obtain  terminal  settings.   Having  retrieved these settings, tput remembers which file
                   descriptor to use when updating settings.

              (2)  if the window size cannot be obtained from the operating system, but the terminal description
                   (or  environment,  e.g.,  LINES  and  COLUMNS  variables  specify this), update the operating
                   system's notion of the window size.

              (3)  the terminal modes will be updated:

                   •   any delays (e.g., newline) specified in the entry will be set in the tty driver,

                   •   tabs expansion will be turned on or off according to the specification in the entry, and

                   •   if tabs are not expanded, standard tabs will be set (every 8 spaces).

              (4)  if present, the  terminal's  initialization  strings  will  be  output  as  detailed  in  the
                   terminfo(5) section on Tabs and Initialization,

              (5)  output is flushed.

              If  an  entry  does  not contain the information needed for any of these activities, that activity
              will silently be skipped.

       reset  This is similar to init, with two differences:

              (1)  before any other initialization, the terminal modes will be reset to a “sane” state:

                   •   set cooked and echo modes,

                   •   turn off cbreak and raw modes,

                   •   turn on newline translation and

                   •   reset any unset special characters to their default values

              (2)  Instead of putting out initialization strings, the terminal's reset strings will be output if
                   present  (rs1,  rs2,  rs3,  rf).   If  the  reset strings are not present, but initialization
                   strings are, the initialization strings will be output.

              Otherwise, reset acts identically to init.

       longname
              If the terminal database is present and an entry  for  the  user's  terminal  exists  (see  -Ttype
              above), then the long name of the terminal will be put out.  The long name is the last name in the
              first line of the terminal's description in the terminfo database [see term(5)].

   Aliases
       tput handles the clear, init and reset commands specially: it allows  for  the  possibility  that  it  is
       invoked by a link with those names.

       If  tput  is  invoked by a link named reset, this has the same effect as tput reset.  The tset(1) utility
       also treats a link named reset specially.

       Before ncurses 6.1, the two utilities were different from each other:

       •   tset utility reset the terminal modes and special characters (not done with tput).

       •   On the other hand, tset's repertoire of terminal capabilities for resetting  the  terminal  was  more
           limited,  i.e.,  only  reset_1string,  reset_2string  and reset_file in contrast to the tab-stops and
           margins which are set by this utility.

       •   The reset program is usually an alias for tset, because of this difference  with  resetting  terminal
           modes and special characters.

       With the changes made for ncurses 6.1, the reset feature of the two programs is (mostly) the same.  A few
       differences remain:

       •   The tset program waits one second when resetting, in case it happens to be a hardware terminal.

       •   The two programs write the terminal initialization strings to different streams (i.e.,. the  standard
           error for tset and the standard output for tput).

           Note:  although  these  programs  write to different streams, redirecting their output to a file will
           capture only part of their  actions.   The  changes  to  the  terminal  modes  are  not  affected  by
           redirecting the output.

       If  tput  is  invoked  by  a link named init, this has the same effect as tput init.  Again, you are less
       likely to use that link because another program named init has a more well-established use.

EXAMPLES

       tput init
            Initialize the terminal according to the type of terminal in the environmental variable TERM.   This
            command  should  be  included  in everyone's .profile after the environmental variable TERM has been
            exported, as illustrated on the profile(5) manual page.

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

       tput cup 0 0
            Send the sequence to move the cursor to row 0, column 0  (the  upper  left  corner  of  the  screen,
            usually known as the “home” cursor position).

       tput clear
            Echo the clear-screen sequence for the current terminal.

       tput cols
            Print the number of columns for the current terminal.

       tput -T450 cols
            Print the number of columns for the 450 terminal.

       bold=`tput smso` offbold=`tput rmso`
            Set  the  shell  variables bold, to begin stand-out mode sequence, and offbold, to end standout mode
            sequence, for the current terminal.  This might be followed by a prompt: echo "${bold}Please type in
            your name: ${offbold}\c"

       tput hc
            Set exit code to indicate if the current terminal is a hard copy terminal.

       tput cup 23 4
            Send the sequence to move the cursor to row 23, column 4.

       tput cup
            Send the terminfo string for cursor-movement, with no parameters substituted.

       tput longname
            Print  the  long  name  from  the  terminfo  database  for  the  type  of  terminal specified in the
            environmental variable TERM.

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

            This example shows tput processing several capabilities in one invocation.  It  clears  the  screen,
            moves  the  cursor to position 10, 10 and turns on bold (extra bright) mode.  The list is terminated
            by an exclamation mark (!) on a line by itself.

FILES

       /etc/terminfo
              compiled terminal description database

       /usr/share/tabset/*
              tab settings for some terminals, in a format appropriate to be  output  to  the  terminal  (escape
              sequences  that  set  margins  and  tabs);  for more information, see the Tabs and Initialization,
              section of terminfo(5)

EXIT CODES

       If the -S option is used, tput checks for errors from each line, and if any errors are  found,  will  set
       the exit code to 4 plus the number of lines with errors.  If no errors are found, the exit code is 0.  No
       indication of which line failed can be given so exit code 1 will never appear.  Exit codes 2,  3,  and  4
       retain  their  usual  interpretation.  If the -S option is not used, the exit code depends on the type of
       capname:

          boolean
                 a value of 0 is set for TRUE and 1 for FALSE.

          string a value of 0 is set if the capname is defined for this terminal type (the value of  capname  is
                 returned  on  standard output); a value of 1 is set if capname is not defined for this terminal
                 type (nothing is written to standard output).

          integer
                 a value of 0 is always set, whether or not capname is  defined  for  this  terminal  type.   To
                 determine if capname is defined for this terminal type, the user must test the value written to
                 standard output.  A value of -1 means that capname is not defined for this terminal type.

          other  reset or init may fail to find their respective files.  In that case, the exit code is set to 4
                 + errno.

       Any other exit code indicates an error; see the DIAGNOSTICS section.

DIAGNOSTICS

       tput prints the following error messages and sets the corresponding exit codes.

       exit code   error message
       ─────────────────────────────────────────────────────────────────────
       0           (capname  is a numeric variable that is not specified in
                   the terminfo(5) database for this  terminal  type,  e.g.
                   tput -T450 lines and tput -T2621 xmc)
       1           no error message is printed, see the EXIT CODES section.
       2           usage error
       3           unknown terminal type or no terminfo database
       4           unknown terminfo capability capname
       >4          error occurred in -S
       ─────────────────────────────────────────────────────────────────────

HISTORY

       The tput command was begun by Bill Joy in 1980.  The initial version only cleared the screen.

       AT&T  System  V  provided a different tput command, whose init and reset  subcommands (more than half the
       program) were incorporated from the reset feature of BSD tset written by Eric Allman.

       Keith Bostic replaced the BSD tput command in 1989 with a new implementation based on the AT&T  System  V
       program  tput.   Like  the  AT&T  program,  Bostic's  version accepted some parameters named for terminfo
       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 I/O
       modes as the earlier BSD tset had done.

       At the same time, Bostic added a shell script named “clear”, which used tput to clear the screen.

       Both of these appeared in 4.4BSD, becoming the “modern” BSD implementation of tput.

       This implementation of tput began from a different source than AT&T or BSD: 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 the  tput  program  (and  other  parts  of
       mytinfo)  in  ncurses in June 1995.  Using the portions dealing with terminal capabilities almost without
       change, Raymond made improvements to the way the command-line parameters were handled.

PORTABILITY

       This implementation of tput differs from AT&T tput in two important areas:

       •   tput capname writes to the standard output.  That need not  be  a  regular  terminal.   However,  the
           subcommands which manipulate terminal modes may not use the standard output.

           The  AT&T  implementation's init and reset commands use the BSD (4.1c) tset source, which manipulates
           terminal modes.  It successively tries standard output, standard error, standard input before falling
           back  to  “/dev/tty”  and  finally  just assumes a 1200Bd terminal.  When updating terminal modes, it
           ignores errors.

           Until changes made after ncurses 6.0, tput did not modify terminal modes.  tput now  uses  a  similar
           scheme,  using  functions  shared  with tset (and ultimately based on the 4.4BSD tset).  If it is not
           able to open a terminal, e.g., when running in cron, tput will return an error.

       •   AT&T tput guesses the type of its capname operands by seeing if all of the characters are numeric, or
           not.

           Most  implementations  which  provide  support  for capname operands use the tparm function to expand
           parameters in it.  That function expects a mixture of numeric and string parameters,  requiring  tput
           to know which type to use.

           This  implementation uses a table to determine the parameter types for the standard capname operands,
           and an internal library function to analyze nonstandard capname operands.

       This implementation (unlike others) can accept both termcap and terminfo names for the  capname  feature,
       if  termcap  support  is  compiled  in.   However,  the  predefined  termcap  and terminfo names have two
       ambiguities in this case (and the terminfo name is assumed):

       •   The termcap name dl corresponds to the terminfo name dl1 (delete one line).
           The terminfo name dl corresponds to the termcap name DL (delete a given number of lines).

       •   The termcap name ed corresponds to the terminfo name rmdc (end delete mode).
           The terminfo name ed corresponds to the termcap name cd (clear to end of screen).

       The longname and -S options, and the parameter-substitution features used in the cup  example,  were  not
       supported in BSD curses before 4.3reno (1989) or in AT&T/USL curses before SVr4 (1988).

       IEEE  Std  1003.1/The  Open Group  Base Specifications Issue 7 (POSIX.1-2008) documents only the operands
       for clear, init and reset.  There are a few interesting observations to make regarding that:

       •   In this implementation, clear is part of the capname support.  The others (init and longname) do  not
           correspond to terminal capabilities.

       •   Other  implementations  of  tput  on  SVr4-based  systems such as Solaris, IRIX64 and HPUX as well as
           others such as AIX and Tru64 provide support for capname operands.

       •   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.

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

       •   X/Open  Curses  Issue  7 documents tput differently, with capname and the other features used in this
           implementation.

       •   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 capabilities database.

       •   While it is certainly possible to write a tput program without using  curses,  none  of  the  systems
           which have a curses implementation provide a tput utility which does not provide the capname feature.

SEE ALSO

       clear(1), stty(1), tabs(1), tset(1), terminfo(5), termcap(3NCURSES).

       This describes ncurses version 6.1 (patch 20180127).

                                                                                                         tput(1)