GRN

Section: User Commands (1)
Updated: local
Index Return to Main Contents

NAME

grn - ditroff preprocessor for gremlin files

SYNOPSIS

grn [ options ] ... [ file ] ...

DESCRIPTION

Grn is a preprocessor for including gremlin pictures in ditroff input. Grn writes to standard output, processing only input lines between two that start with `.GS' and `.GE'. Those lines must contain grn commands (see below). These commands request a gremlin file, and the picture in that file is converted and placed in the ditroff input stream. The .GS may be followed by a C, L, or R to center, left or right justify the whole gremlin picture (default justification is center). If no file is mentioned, the standard input is read. At the end of the picture, the position on the page is the bottom of the gremlin picture. If the grn entry is ended with `.GF' instead of `.GE', the position is left at the top of the picture. The following command-line options are understood:

-Pdev: Prepare output for printer dev. The default is varian (or versatec since the two are equivalent). See ditroff(1) for acceptable dev's.
-Ldir: Set the library to directory dir. If a gremlin file cannot be found in the current directory, dir is prepended to the filename for a second try. The default library directory is /usr/local/gremlib.

GRN COMMANDS

Each input line between the `.GS' and `.GE' may have one grn command. Commands consist of one or two strings separated by white space, the first string being the command and the second its operand. Commands may be upper or lower case and abbreviated down to one character.

Commands that affect a picture's environment (those listed before default, below) are only in effect for the current picture: the environment is reinitialized to the defaults at the start of the next picture. The commands are as follows:

1 N: (2, 3, or 4) Set gremlin's text size number 1 (2, 3, or 4) to N points. The default is 12 (16, 24, and 36).
roman ff: (italics, bold, or special) Set the roman (italics, bold, or special) font to ditroff's font ff (either a name or number). The default is R (I, B, and S).
l N: Set the stipple font to ditroff's stipple font ff (name or number). The command stipple can be substituted, but only abbreviated down as far as `st' to avoid confusion with special. There is NO default for stipples (unless one is set by the default command), and it is illegal to include a gremlin picture with polygons without specifying a stipple font.
x N: Magnify the picture (in addition to any default magnification) by N, a floating point number > 0. The command scale may be substituted, abbreviated down to `sc'.
narrow N: (medium, or thick) Set the thickness of gremlin's narrow (medium or thick) lines to N. The default is 1 (3 and 5) pixels.
pointscale <off/on>: Scale text to match the picture. Gremlin text is usually printed in the point size specified in 1, 2, 3 or 4 regardless of any scaling factors in the picture. Setting pointscale will cause the point sizes to scale with the picture (within ditroff's limitations, of course). An operand of anything but off will turn text scaling on.
default: Reset the picture environment defaults to the settings in the current picture. This is meant to be used as a global parameter setting mechanism at the beginning of the ditroff input file, but can be used at any time to reset the default settings.
width N: Forces the picture to be N inches wide. This overrides any scaling factors present in the same picture. width 0 is ignored.
height N: Forces picture to be N inches high, overriding other scaling factors. If both ``width'' and ``height'' are specified the tighter constraint will determine the scale of the picture. Height and width commands are not saved with a default command. They will, however, affect point size scaling if that option is set.
file name: Get picture from gremlin file name from the current directory (or in the library directory see the -L option above). If two file commands are given, the second one overrides the first. If name doesn't exist, an error message is reported and processing continues from the .GE line.

NOTES ABOUT DITROFF

Since grn is a preprocessor, it doesn't know about current indents, point sizes, margins, number registers, etc. Consequently, no troff input can be placed between the ``.GS'' and ``.GE''. However, gremlin text is now processed by troff, so anything legal in a single line of troff input is legal in a line of gremlin text (barring ``.'' directives at the beginning of a line).

When using grn along with other preprocessors, it is best to run tbl before grn, pic, and/or ideal to avoid overworking tbl. Eqn should always be run last.

A picture is considered an entity, but that doesn't stop troff from trying to break it up if it falls off the end of a page. Placing the picture between ``keeps'' in either the -ms or -me macros will ensure proper placement.

The .GS and .GE lines are sent through to ditroff and used in the -ms and -me macros for adjusting the picture. There are -mg macros available for grn, pic and ideal if you don't use -ms or -me. Grn uses number registers g1 through g9 and sets register g1 and g2 to the width and height of the gremlin figure (in device units) before entering the .GS (this is for those who want to rewrite these macros).

FILES

/usr/lib/font/devxxx/DESC.out device xxx description file

AUTHOR

David Slattengren

This document was created by man2html, using the manual pages.
Time: 22:49:52 GMT, December 11, 2024

GRN