PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

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

PROLOG         top

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

NAME         top

       tput — change terminal characteristics

SYNOPSIS         top

       tput [−T type] operand...

DESCRIPTION         top

       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         top

       The tput utility shall conform to the Base Definitions volume of
       POSIX.1‐2008, 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         top

       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         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       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.1‐2008, 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         top

       Default.

STDOUT         top

       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         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       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         top

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

       The following sections are informative.

APPLICATION USAGE         top

       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         top

        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         top

       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.1‐2008 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         top

       None.

SEE ALSO         top

       stty(1p), tabs(1p)

       The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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                 2013                            TPUT(1P)