hp(C)                           19 June 1992                           hp(C)


 Name

    hp - handle special functions of Hewlett-Packard terminals

 Syntax

    hp [ -e ] [ -m ]

 Description

    hp supports the special functions of the Hewlett-Packard 2640 series of
    terminals, with the primary purpose of producing accurate representations
    of most nroff output.  A typical usage is in conjunction with text pro-
    cessing software:

       nroff -h files ... | hp

    Regardless of the hardware options on your terminal, hp tries to do sen-
    sible things with underlining and reverse line-feeds.  If the terminal
    has the ``display enhancements'' feature, subscripts and superscripts can
    be indicated in distinct ways.  If it has the ``mathematical-symbol''
    feature, Greek and other special characters can be displayed.

    The flags are as follows:

    -e  It is assumed that your terminal has the ``display enhancements''
        feature, and so maximal use is made of the added display modes.
        Overstruck characters are presented in the Underlined mode.  Super-
        scripts are shown in Half-bright mode, and subscripts in Half-bright,
        Underlined mode.  If this flag is omitted, hp assumes that your ter-
        minal lacks the ``display enhancements'' feature.  In this case, all
        overstruck characters, subscripts, and superscripts are displayed in
        Inverse Video mode, that is, dark-on-light, rather than the usual
        light-on-dark.

    -m  Requests minimization of output by changing new-lines to ^M's.  Any
        contiguous sequence of 3 or more new-lines is converted into a
        sequence of only 2 new-lines; that is, any number of successive blank
        lines produces only a single blank output line.  This allows you to
        retain more actual text on the screen.

    With regard to Greek and other special characters, hp provides the same
    set as 300(C) , except that ``not'' is approximated by a right arrow, and
    only the top half of the integral sign is shown.

 Diagnostics

    line too long if the representation of a line exceeds 1,024 characters.
    The exit codes are 0 for normal termination, 2 for all errors.

 See also

    300(C) , greek(C)

 Notes

    An ``overstriking sequence'' is defined as a printing character followed
    by a backspace followed by another printing character.  In such
    sequences, if either printing character is an underscore, the other
    printing character is shown underlined or in Inverse Video; otherwise,
    only the first printing character is shown (again, underlined or in
    Inverse Video).  Nothing special is done if a backspace is adjacent to an
    ASCII control character.  Sequences of control characters (for example,
    reverse line-feeds, backspaces) can make text ``disappear.''  In particu-
    lar, tables generated by tbl(CT) that contain vertical lines will often
    be missing the lines of text that contain the ``foot'' of a vertical
    line, unless the input to hp is piped through col(C) .

    Although some terminals do provide numerical superscript characters, no
    attempt is made to display them.