man > post-grohtml(1)

grohtml(1)                             General Commands Manual                            grohtml(1)

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

Synopsis
       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
       The  GNU  roff  system's  HTML support consists of a preprocessor, pre-grohtml, and an output
       driver, post-grohtml; together, they translate ]8;;man:roff(7)\roff(7)]8;;\ documents to  HTML.   Because  a  pre‐
       processor  is (uniquely) required for this output driver, users should invoke grohtml via the
       ]8;;man:groff(1)\groff(1)]8;;\ command with the -Thtml or -Txhtml options.  (In this installation, ps  is  the  de‐
       fault  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.  Output is
       written to the standard output stream.

       grohtml invokes groff twice.  In the first pass, the preprocessor  pre-grohtml  renders  pic‐
       tures,  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 ]8;;man:troff(1)\troff(1)]8;;\ to HTML.

       grohtml writes output encoded in UTF-8 and has built-in HTML entities for  all  non-composite
       Unicode characters.  In spite of this, groff may issue warnings about unknown special charac‐
       ters  if  they can't be found during the first pass.  Such warnings can be safely ignored un‐
       less 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 ]8;;man:groff_font(5)\groff_font(5)]8;;\.

   Dependencies
       pre-grohtml generates an image whenever an eqn equation, tbl table, or pic picture is encoun‐
       tered 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
       --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 im‐
              ages.  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 de‐
              scription 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 fol‐
              lowing 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  automati‐
              cally 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 let‐
              ter 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
       GROFF_FONT_PATH
              lists  directories  in  which to search for devhtml, grohtml's directory of device and
              font description files.  See ]8;;man:troff(1)\troff(1)]8;;\ and ]8;;man:groff_font(5)\groff_font(5)]8;;\.

       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 ]8;;man:gmtime(3)\gmtime(3)]8;;\ and ]8;;man:asctime(3)\asctime(3)]8;;\, and recorded in an HTML comment.

       TZ     The time zone to use when converting the current  time  to  human-readable  form;  see
              ]8;;man:tzset(3)\tzset(3)]8;;\.  If SOURCE_DATE_EPOCH is used, it is always converted to human-readable form
              using UTC.

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

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

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

       /usr/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 ]8;;man:groff(1)\groff(1)]8;;\ for details about where such files are created.

Bugs
       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
       ]8;;man:groff(1)\groff(1)]8;;\, ]8;;man:troff(1)\troff(1)]8;;\, ]8;;man:groff_font(5)\groff_font(5)]8;;\

groff 1.23.0                                31 March 2024                                 grohtml(1)