NAME

       tput - change terminal characteristics

SYNOPSIS

       tput [-T type] operand...

DESCRIPTION

       The  tput  utility shall display terminal-dependent information.  The manner in which this information is
       retrieved is unspecified. The information displayed shall  clear  the  terminal  screen,  initialize  the
       user's  terminal, or reset the user's terminal, depending on the operand given. The exact consequences of
       displaying this information are unspecified.

OPTIONS

       The tput utility shall conform to the Base Definitions  volume  of  IEEE Std 1003.1-2001,  Section  12.2,
       Utility Syntax Guidelines.

       The following option shall be supported:

       -T  type
              Indicate  the  type  of terminal. If this option is not supplied and the TERM variable is unset or
              null, an unspecified default terminal  type  shall  be  used.  The  setting  of  type  shall  take
              precedence over the value in TERM .

OPERANDS

       The following strings shall be supported as operands by the implementation in the POSIX locale:

       clear  Display the clear-screen sequence.

       init   Display the sequence that initializes the user's terminal in an implementation-defined manner.

       reset  Display the sequence that resets the user's terminal in an implementation-defined manner.

       If  a  terminal  does  not  support  any of the operations described by these operands, this shall not be
       considered an error condition.

STDIN

       Not used.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of tput:

       LANG   Provide a default value for the internationalization variables that are unset or  null.  (See  the
              Base  Definitions  volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for
              the  precedence  of  internationalization  variables  used  to  determine  the  values  of  locale
              categories.)

       LC_ALL If  set  to  a  non-empty  string value, override the values of all the other internationalization
              variables.

       LC_CTYPE
              Determine the locale for the interpretation of sequences of bytes of text data as characters  (for
              example, single-byte as opposed to multi-byte characters in arguments).

       LC_MESSAGES
              Determine  the locale that should be used to affect the format and contents of diagnostic messages
              written to standard error.

       NLSPATH
              Determine the location of message catalogs for the processing of LC_MESSAGES .

       TERM   Determine the terminal type. If this variable is unset or null,  and  if  the  -T  option  is  not
              specified, an unspecified default terminal type shall be used.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       If standard output is a terminal device, it may be used for writing the appropriate sequence to clear the
       screen or reset or initialize the terminal. If standard  output  is  not  a  terminal  device,  undefined
       results occur.

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0     The requested string was written successfully.

        1     Unspecified.

        2     Usage error.

        3     No information is available about the specified terminal type.

        4     The specified operand is invalid.

       >4     An error occurred.

CONSEQUENCES OF ERRORS

       If  one  of  the  operands  is  not  available  for the terminal, tput continues processing the remaining
       operands.

       The following sections are informative.

APPLICATION USAGE

       The difference between resetting and initializing a terminal is left unspecified, as  they  vary  greatly
       based on hardware types.  In general, resetting is a more severe action.

       Some  terminals  use  control  characters to perform the stated functions, and on such terminals it might
       make sense to use tput to store the initialization strings in a file or environment  variable  for  later
       use.  However,  because  other  terminals might rely on system calls to do this work, the standard output
       cannot be used in a portable manner, such as the following non-portable constructs:

              ClearVar=`tput clear`
              tput reset | mailx -s "Wake Up" ddg

EXAMPLES

        1. Initialize the terminal according to the type of terminal in the environmental variable TERM  .  This
           command can be included in a .profile file.

           tput init

        2. Reset a 450 terminal.

           tput -T 450 reset

RATIONALE

       The list of operands was reduced to a minimum for the following reasons:

        * The  only  features  chosen  were  those that were likely to be used by human users interacting with a
          terminal.

        * Specifying the full terminfo set was not considered desirable, but the  standard  developers  did  not
          want to select among operands.

        * This  volume  of  IEEE Std 1003.1-2001  does  not  attempt  to provide applications with sophisticated
          terminal handling capabilities, as that falls outside of its assigned scope and  intersects  with  the
          responsibilities of other standards bodies.

       The  difference  between resetting and initializing a terminal is left unspecified as this varies greatly
       based on hardware types.  In general, resetting is a more severe action.

       The exit status of 1 is historically reserved for finding out if a Boolean operand is not  set.  Although
       the  operands  were  reduced  to a minimum, the exit status of 1 should still be reserved for the Boolean
       operands, for those sites that wish to support them.

FUTURE DIRECTIONS

       None.

SEE ALSO

       stty , tabs

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc  and  The  Open Group. In the event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .