It is possible to have whitespace between a command line option and its parameter.
Please note that currently only the -me macro package has support for .GS, .GE, and .GF.
The following command-line options are understood:
|-Tdev||Prepare output for printer dev. The default device is ps. See groff(1) for acceptable devices.|
|-Mdir||Prepend dir to the default search path for gremlin files. The default path is (in that order) the current directory, the home directory, /usr/lib/groff/site-tmac, /usr/share/groff/site-tmac, and /usr/share/groff/184.108.40.206/tmac.|
|-Fdir||Search dir for subdirectories devname (name is the name of the device) for the DESC file before the default font directories /usr/share/groff/site-font, /usr/share/groff/220.127.116.11/font, and /usr/lib/font.|
|-C||Recognize .GS and .GE (resp. .GF) even when followed by a character other than space or newline.|
|-v||Print the version number.|
Commands that affect a pictures environment (those listed before default, see 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:
|4 N||Set gremlins text size number 1 (2, 3, or 4) to N points. The default is 12 (resp. 16, 24, and 36).|
|Set the roman (italics, bold, or special) font to troffs font f (either a name or number). The default is R (resp. I, B, and S).|
|Set the stipple font to troffs stipple font f (name or number). The command stipple may be 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 invalid to include a gremlin picture with polygons without specifying a stipple font.|
|scale N||Magnify the picture (in addition to any default magnification) by N, a floating point number larger than zero. The command scale may be abbreviated down to sc.|
|thick N||Set the thickness of gremlins narrow (resp. medium and thick) lines to N times 0.15pt (this value can be changed at compile time). The default is 1.0 (resp. 3.0 and 5.0), which corresponds to 0.15pt (resp. 0.45pt and 0.75pt). A thickness value of zero selects the smallest available line thickness. Negative values cause the line thickness to be proportional to the current point size.|
|Scale text to match the picture. Gremlin text is usually printed in the point size specified with the commands 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 troffs limitations, of course). An operand of anything but off will turn text scaling on.|
|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 troff 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.|
|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.|
|Get picture from gremlin file name located the current directory (or in the library directory; see the -M option above). If two file commands are given, the second one overrides the first. If name doesnt exist, an error message is reported and processing continues from the .GE 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 doesnt stop troff from trying to break it up if it falls off the end of a page. Placing the picture between keeps in -me macros will ensure proper placement.
grn uses troffs number registers g1 through g9 and sets registers g1 and g2 to the width and height of the gremlin figure (in device units) before entering the .GS request (this is for those who want to rewrite these macros).
|0 240.00 128.00||0 240.00 128.00|
|240.00 128.00||240.00 128.00|
|185.00 120.00||185.00 120.00|
|240.00 120.00||240.00 120.00|
|296.00 120.00||296.00 120.00|
|2 3||2 3|
|10 A Triangle||10 A Triangle|
|224.00 416.00||224.00 416.00|
|96.00 160.00||96.00 160.00|
|384.00 160.00||384.00 160.00|
|5 1||5 1|
|Table 1. File examples|
|o||The first line of each gremlin file contains either the string gremlinfile (AED version) or sungremlinfile (SUN/X11)|
|o||The second line of the file contains an orientation, and x and y values for a positioning point, separated by spaces. The orientation, either 0 or 1, is ignored by the SUN/X11 version. 0 means that gremlin will display things in horizontal format (drawing area wider than it is tall, with menu across top). 1 means that gremlin will display things in vertical format (drawing area taller than it is wide, with menu on left side). x and y are floating point values giving a positioning point to be used when this file is read into another file. The stuff on this line really isnt all that important; a value of 1 0.00 0.00 is suggested.|
|o||The rest of the file consists of zero or more element specifications. After the last element specification is a line containing the string -1.|
|o||Lines longer than 127 characters are chopped to this limit.|
The first line of each element contains a single decimal number giving the
type of the element
(AED version) or its ASCII name
See Table 2.
|o||After the object type comes a variable number of lines, each specifying a point used to display the element. Each line contains an x-coordinate and a y-coordinate in floating point format, separated by spaces. The list of points is terminated by a line containing the string -1.0 -1.0 (AED version) or a single asterisk, * (SUN/X11 version).|
After the points comes a line containing two decimal values, giving the
brush and size for the element.
The brush determines the style in which things are drawn.
For vectors, arcs, and curves there are six legal brush values:
For polygons, one more value, 0, is legal. It specifies a polygon with an invisible border. For text, the brush selects a font as follows:
If youre using grn to run your pictures through groff, the font is really just a starting font: The text string can contain formatting sequences like \fI or \d which may change the font (as well as do many other things). For text, the size field is a decimal value between 1 and 4. It selects the size of the font in which the text will be drawn. For polygons, this size field is interpreted as a stipple number to fill the polygon with. The number is used to index into a stipple font at print time.
|o||The last line of each element contains a decimal number and a string of characters, separated by a single space. The number is a count of the number of characters in the string. This information is only used for text elements, and contains the text string. There can be spaces inside the text. For arcs, curves, and vectors, this line of the element contains the string 0.|
|Device description file for device name.|
$ grn gremlin_image_file > output.ps <Above command will produce the output file where image is of size 1x1 inch
.GS > width 1 > height 1 > .GS > EOD
$ grn > output.ps <This will produce the same output as previous command but the input image is specified as grn command.
.GS > file gremlin_image_file > width 1 > height 1 > .GS > EOD