tput(1p) — Linux manual page

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

PROLOG

       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

       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(1p), tabs(1p)

       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(1P)

Pages that refer to this page: tabs(1p)

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