grohtml

Name
Synopsis
Description
Options
Usage
Dependencies
Files
Environment
Bugs
See also

Name

grohtml - groff output driver for HTML

Synopsis

grohtml [-bhlnprVy] [-a aa-text-bits] [-D dir] [-F dir] [-g aa-graphic-bits] [-i resolution] [-I image-stem] [-j filename] [-o image-vertical-offset] [-s size] [-S level] [-x html-dialect] [file ...]
grohtml --help
grohtml -v grohtml --version

Description

The grohtml front end (which consists of a preprocessor, pre-grohtml, and a device driver, post-grohtml) translates the output of GNU roff to HTML. Users should always invoke grohtml via the groff(1) command with the -Thtml option. If no operands are given, or if file is “-”, grohtml reads the standard input stream. HTML output is written to the standard output stream. When grohtml is run by groff, options can be passed to grohtml using groff’s -P option.

grohtml invokes groff twice. In the first pass, pictures, equations, and tables are rendered using the ps device, and in the second pass HTML output is generated by the html device.

grohtml always writes output in UTF-8 encoding and has built-in 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. Such warnings can be safely ignored unless the special characters appear inside a table or equation.

Options

--help displays a usage message and -v shows version information; both exit afterward.
-a 
aa-text-bits

Number of bits of antialiasing information to be used by text when generating PNG images. The default is 4 but valid values are 0, 1, 2, and 4. Note that your version of gs needs to support the -dTextAlphaBits and -dGraphicAlphaBits options in order to exploit antialiasing. A value of 0 stops grohtml from issuing antialiasing commands to gs.

-b

Initialize the background color to white.

-D dir

Instruct grohtml to place all image files into directory dir.

-e

This option should not be directly specified; it is an internal option used by groff when -Thtml or -Txhtml is specified. grohtml’s preprocessor uses it to determine whether eqn should be directed to produce MathML (if -Txhtml is specified).

-F dir

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

-g aa-graphic-bits

Number of bits of antialiasing information to be used by graphics when generating PNG images. The default is 4 but valid values are 0, 1, 2, and 4. Note your version of gs needs to support the -dTextAlphaBits and -dGraphicAlphaBits options in order to exploit antialiasing. A value of 0 stops grohtml from issuing antialiasing commands to gs.

-h

Generate section and number headings by using <B>...</B> and increasing the font size, rather than using the <Hn>...</Hn> tags.

-i resolution

Select the resolution for all images. By default this is 100 pixels per inch. Example: -i200 indicates 200 pixels per inch.

-I stem

Determine the image stem name. If omitted grohtml uses grohtml-XXXXX (where XXXXX is the process ID).

-j filename

Instruct grohtml to split the HTML output into multiple files. The filename is the stem and output is written to a new file at each section heading (but see option -S below) named filename-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 flag is automatically turned on if a heading contains an image.

-o vertical-offset

Specify the vertical offset of images in points.

-p

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

-r

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

-s size

Set the base point size of the source file. Thereafter when this point size is used in the source it will correspond to the HTML base size. Every increase of two points in the source will yield a <big> tag, and conversely when a decrease of two points is seen a <small> tag is emitted.

-S level

When splitting HTML output (see option -j above), split at each nested heading level defined by 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 dialect

Select HTML dialect. Currently, 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 directly invoked by the user as it is an internal option utilized by groff when -Thtml or -Txhtml is specified.

-y

Produce a right-justified groff signature at the end of the document. This is only generated if the -V flag is also specified.

Usage

There are styles called R, I, B, and BI mounted at font positions 1 to 4.

Dependencies

grohtml is dependent upon the PNG utilities (pnmcut, pnmcrop, pnmtopng) and GhostScript (gs). pnmtopng (version 2.37.6 or greater) and pnmcut from the netpbm package (version 9.16 or greater) will work also. It is also dependent upon psselect from the PSUtils package. Images are generated whenever a table, picture, equation or line (such as a baseline rule or box rule) is encountered.

Files

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

Environment

GROFF_FONT_PATH

A list of directories in which to search for the devname directory in addition to the default ones. See troff(1) and groff_font(5) for more details.

SOURCE_DATE_EPOCH

A timestamp (expressed as seconds since the Unix epoch) to use as the creation timestamp in place of the current time.

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

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