TPUT(1)                    POSIX Programmer's Manual                   TPUT(1)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

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
       POSIX.1-2017, 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 POSIX.1-2017, 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 POSIX.1-2017 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

       The Base Definitions volume of POSIX.1-2017, Chapter _8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                              TPUT(1)
