grohtml(1) — Linux manual page

Name | Synopsis | Description | Options | Environment | Files | Bugs | See also | COLOPHON

grohtml(1)               General Commands Manual              grohtml(1)

Name         top

       grohtml, post-grohtml, pre-grohtml - groff output driver for HTML

Synopsis         top

       pre-grohtml [-epV] [-a anti-aliasing-text-bits] [-D image-
                   directory] [-F font-directory] [-g anti-aliasing-
                   graphic-bits] [-i resolution] [-I image-stem] [-o
                   image-vertical-offset] [-x html-dialect] troff-
                   command troff-argument ...

       pre-grohtml --help

       pre-grohtml -v

       pre-grohtml --version

       post-grohtml [-bCGhlnrVy] [-F font-directory] [-j output-stem]
                    [-s base-point-size] [-S heading-level] [-x html-
                    dialect] [file ...]

       post-grohtml --help

       post-grohtml -v

       post-grohtml --version

Description         top

       The GNU roff system's HTML support consists of a preprocessor,
       pre-grohtml, and an output driver, post-grohtml; together, they
       translate roff(7) documents to HTML.  Because a preprocessor is
       (uniquely) required for this output driver, users should invoke
       grohtml via the groff(1) command with the -Thtml or -Txhtml
       options.  (In this installation, ps is the default output
       device.)  Use groff's -P option to pass any options shown above
       to grohtml.  If no operands are given, or if file is “-”, grohtml
       reads the standard input stream.  It writes to the standard
       output stream.

       grohtml invokes groff twice.  In the first pass, the preprocessor
       pre-grohtml renders pictures, equations, and tables as images in
       PostScript format using the ps output device.  In the second
       pass, the output driver post-grohtml translates the output of
       troff(1) to HTML.

       grohtml writes UTF-8-encoded output and has built-in HTML
       entities for all non-composite Unicode characters.  In spite of
       this, groff may issue warnings about unknown special characters
       if they can't be found during the first pass.  You can ignore
       these warnings unless the special characters appear inside a
       table or equation.

   Typefaces
       grohtml supports the standard four styles: R (roman), I (italic),
       B (bold), and BI (bold-italic).  Fonts are grouped into families
       T and C having members in each style.

              TR     Times roman
              TI     Times italic
              TB     Times bold
              TBI    Times bold-italic
              CR     Courier roman
              CI     Courier italic
              CB     Courier bold
              CBI    Courier bold-italic

       A special font, S, is also provided to accommodate roff documents
       that expect it to always be available.

   Font description files
       The font description files used with grohtml expose the same
       glyph repertoire in their charset sections.  See groff_font(5).

   Dependencies
       pre-grohtml generates an image whenever an eqn equation, tbl
       table, or pic picture is encountered in the input.  grohtml
       therefore may run several commands as part of its operation.
       These include the Netpbm tools pnmcrop, pnmcut, and pnmtopng;
       Ghostscript (gs); and the PSUtils tool psselect.

Options         top

       --help displays a usage message, while -v and --version show
       version information; all exit afterward.

       -a anti-aliasing-text-bits
              Number of bits of antialiasing information to be used by
              text when generating PNG images.  The default is 4 but 0,
              1, and 2 are also valid.  Your system's version of gs must
              support the -dTextAlphaBits option in order to exploit
              antialiasing.  A value of 0 stops grohtml from issuing
              antialiasing commands to gs.

       -b     Initialize the background color to white.

       -C     Suppress output of “CreationDate:” HTML comment.

       -D image-directory
              Instruct grohtml to place all image files into directory
              image-directory.

       -e     Direct eqn to produce MathML.

              This option should not be manually specified; it is
              synthesized by groff depending on whether it was given the
              -Thtml or -Txhtml option.

       -F font-directory
              Prepend directory font-directory/devname to the search
              path for font and device description files; name is the
              name of the device, usually html.

       -g anti-aliasing-graphic-bits
              Number of bits of antialiasing information to be used by
              graphics when generating PNG images.  The default is 4 but
              0, 1, and 2 are also valid.  Your system's version of gs
              must support the -dGraphicAlphaBits option in order to
              exploit antialiasing.  A value of 0 stops grohtml from
              issuing antialiasing commands to gs.

       -G     Suppress output of “Creator:” HTML comment.

       -h     Generate section headings by using HTML B elements and
              increasing the font size, rather than HTML H elements.

       -i resolution
              Set the image resolution in pixels per inch; the default
              is 100.

       -I image-stem
              Determine the image file name stem.  If omitted, grohtml
              uses grohtml-XXXXX (where XXXXX is the process ID).  A
              dash is appended to the stem to separate it from the
              following image number.

       -j output-stem
              Instruct grohtml to split the HTML output into multiple
              files.  Output is written to a new file at each section
              heading (but see option -S below) named output-
              stem-n.html.

       -l     Turn off the production of automatic section links at the
              top of the document.

       -n     Generate simple heading anchors whenever a section/number
              heading is found.  Without the option the anchor value is
              the textual heading.  This can cause problems when a
              heading contains a “?” on older versions of some browsers.
              This feature is automatically enabled if a heading
              contains an image.

       -o image-vertical-offset
              Specify the vertical offset of images in points.

       -p     Display page rendering progress to the standard error
              stream.  grohtml displays a page number only when an image
              is required.

       -r     Turn off the automatic header and footer line (HTML rule).

       -s base-type-size
              Set the document's base type size in points.  When this
              size is used in the source, it corresponds to the HTML
              base type size.  Every increase of two points in the
              source will produce a “big” element, and conversely when a
              decrease of two points is seen, a “small” element is
              emitted.

       -S heading-level
              When splitting HTML output (see option -j above), split at
              each nested heading level defined by heading-level, or
              higher).  The default is 1.

       -V     Create an XHTML or HTML validator button at the bottom of
              each page of the document.

       -x html-dialect
              Select HTML dialect.  Currently, html-dialect should be
              either the digit 4 or the letter x, which indicates
              whether grohtml should generate HTML 4 or XHTML,
              respectively.

              This option should not be manually specified; it is
              synthesized by groff depending on whether it was given the
              -Thtml or -Txhtml option.

       -y     Produce a right-aligned groff signature at the end of the
              document (only if -V is also specified).

Environment         top

       GROFF_FONT_PATH
              lists directories in which to search for devhtml,
              grohtml's directory of device and font description files.
              See troff(1) and groff_font(5).

       SOURCE_DATE_EPOCH
              A timestamp (expressed as seconds since the Unix epoch) to
              use as the output creation timestamp in place of the
              current time.  The time is converted to human-readable
              form using gmtime(3) and asctime(3), and recorded in an
              HTML comment.

       TZ     The time zone to use when converting the current time to
              human-readable form; see tzset(3).  If SOURCE_DATE_EPOCH
              is used, it is always converted to human-readable form
              using UTC.

Files         top

       /usr/local/share/groff/1.23.0/font/devhtml/DESC
              describes the html output device.

       /usr/local/share/groff/1.23.0/font/devhtml/F
              describes the font known as F on device html.

       /usr/local/share/groff/1.23.0/tmac/html.tmac
              defines font mappings, special characters, and colors for
              use with the html output device.  It is automatically
              loaded by troffrc when either of the html or xhtml output
              devices is selected.

       /usr/local/share/groff/1.23.0/tmac/html-end.tmac
              finalizes setup of the html output device.  It is
              automatically loaded by troffrc-end when either of the
              html or xhtml output devices is selected.

       grohtml uses temporary files.  See groff(1) for details about
       where such files are created.

Bugs         top

       grohtml is still beta code.

       grohtml does not truly support hyphenation, but you can fool it
       into hyphenating long input lines, which can appear in HTML
       output with a hyphenated word followed by a space but no line
       break.

See also         top

       groff(1), troff(1), groff_font(5)

COLOPHON         top

       This page is part of the groff (GNU troff) project.  Information
       about the project can be found at 
       ⟨http://www.gnu.org/software/groff/⟩.  If you have a bug report
       for this manual page, see ⟨http://www.gnu.org/software/groff/⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://git.savannah.gnu.org/git/groff.git⟩ on 2024-06-14.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2024-06-10.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

groff 1.23.0.1273-9d53-dirty   6 June 2024                    grohtml(1)