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 .

IEEE/The Open Group                                   2003                                               TPUT(P)