Provide workarounds for older printers, broken spoolers, and previewers. Normally grops produces output at PostScript LanguageLevel~2 that conforms to the Document Structuring Conventions version 3.0. Some older printers, spoolers, and previewers cant handle such output. The value of~ n controls what grops does to make its output acceptable to such programs. A value of~0 will cause grops not to employ any workarounds.
Add~1 if no %%Begin Document Setup and %%End Document Setup comments should be generated; this is needed for early versions of TranScript that get confused by anything between the %%End Prolog comment and the first %%Page comment.
Add~2 if lines in included files beginning with %! should be stripped out; this is needed for Suns pageview previewer.
Add~4 if %%Page, %%Trailer and %%End Prolog comments should be stripped out of included files; this is needed for spoolers that dont understand the %%Begin Document and %%End Document comments.
Add~8 if the first line of the PostScript output should be %!PS-Adobe-2.0 rather than %!PS-Adobe-3.0; this is needed when using Suns Newsprint with a printer that requires page reversal.
Add~16 if no media size information should be included in the document (this is, neither use %%Document Media nor the setpagedevice PostScript command). This was the behaviour of groff version 1.18.1 and earlier; it is needed for older printers which dont understand PostScript LanguageLevel~2.
The default value can be specified by a
command in the DESC file. Otherwise the default value is~0.
Print n copies of each page.
Prepend directory dir/devname to the search path for prologue, font, and device description files; name is the name of the device, usually ps.
Guess the page length. This generates PostScript code that guesses the page length. The guess will be correct only if the imageable area is vertically centered on the page. This option allows you to generate documents that can be printed both on letter (8.5×11) paper and on A4 paper without change.
Print the document in landscape format.
Turn manual feed on for the document.
Set physical dimension of output medium. This overrides the papersize, paperlength, and paperwidth commands in the DESC file; it accepts the same arguments as the papersize command. See groff_font (5) for details.
Use the file prologue-file (in the font path) as the prologue instead of the default prologue file prologue. This option overrides the environment variable GROPS_PROLOGUE.
Lines should be drawn using a thickness of n~ thousandths of an em. If this option is not given, the line thickness defaults to 0.04~em.
There is also the following font which is not a member of a family:
There are also some special fonts called S for the PS Symbol font, and SS, containing slanted lowercase Greek letters taken from PS Symbol. Zapf Dingbats is available as ZD and a reversed version of ZapfDingbats (with symbols pointing in the opposite direction) is available as ZDR; most characters in these fonts are unnamed and must be accessed using [rs]N.
The default color for [rs]m and [rs]M is black; for colors defined in the rgb color space, setrgbcolor is used, for cmy and cmyk setcmykcolor, and for gray setgray. Note that setcmykcolor is a PostScript LanguageLevel~2 command and thus not available on some older printers.
grops understands various X~commands produced using the [rs]X escape sequence; grops will only interpret commands that begin with a ps: tag.
[rs]Xps: exec code
This executes the arbitrary PostScript commands in code. The PostScript currentpoint will be set to the position of the [rs]X command before executing code. The origin will be at the top left corner of the page, and y~coordinates will increase down the page. A procedure~ u will be defined that converts groff units to the coordinate system in effect. For example,
.nr x 1i [rs]Xps: exec [rs]nx u 0 rlineto stroke
will draw a horizontal line one inch long. code may make changes to the graphics state, but any changes will persist only to the end of the page. A dictionary containing the definitions specified by the def and mdef will be on top of the dictionary stack. If your code adds definitions to this dictionary, you should allocate space for them using [rs]Xps mdef n. Any definitions will persist only until the end of the page. If you use the [rs]Y escape sequence with an argument that names a macro, code can extend over multiple lines. For example,
.nr x 1i
[rs]nx u 0 rlineto
is another way to draw a horizontal line one inch long.
[rs]Xps: file name
This is the same as the exec command except that the PostScript code is read from file name.
[rs]Xps: def code
Place a PostScript definition contained in code in the prologue. There should be at most one definition per [rs]X command. Long definitions can be split over several [rs]X commands; all the code arguments are simply joined together separated by newlines. The definitions are placed in a dictionary which is automatically pushed on the dictionary stack when an exec command is executed. If you use the [rs]Y escape sequence with an argument that names a macro, code can extend over multiple lines.
[rs]Xps: mdef n code
Like def, except that code may contain up to n~ definitions. grops needs to know how many definitions code contains so that it can create an appropriately sized PostScript dictionary to contain them.
Import a PostScript graphic from file. The arguments llx, lly, urx, and ury give the bounding box of the graphic in the default PostScript coordinate system; they should all be integers; llx and lly are the x and y~coordinates of the lower left corner of the graphic; urx and ury are the x and y~coordinates of the upper right corner of the graphic; width and height are integers that give the desired width and height in groff units of the graphic. The graphic will be scaled so that it has this width and height and translated so that the lower left corner of the graphic is located at the position associated with [rs]X command. If the height argument is omitted it will be scaled uniformly in the x and y~directions so that it has the specified width. Note that the contents of the [rs]X command are not interpreted by troff; so vertical space for the graphic is not automatically added, and the width and height arguments are not allowed to have attached scaling indicators. If the PostScript file complies with the Adobe Document Structuring Conventions and contains a %%Bounding Box comment, then the bounding box can be automatically extracted from within groff by using the psbb request.
See groff_tmac(5) for a description of the PSPIC macro which provides a convenient high-level interface for inclusion of PostScript graphics.
No output will be generated for text and drawing commands that are bracketed with these [rs]X commands. These commands are intended for use when output from troff will be previewed before being processed with grops; if the previewer is unable to display certain characters or other constructs, then other substitute characters or constructs can be used for previewing by bracketing them with these [rs]X commands.
For example, gxditview is not able to display a proper [rs](em character because the standard X11 fonts do not provide it; this problem can be overcome by executing the following request
In this case, gxditview will be unable to display the [rs](em character and will draw the line, whereas grops will print the [rs](em character and ignore the line (this code is already in file Xps.tmac which will be loaded if a documented intended for grops is previewed with gxditview).
The input to grops must be in the format output by troff(1). This is described in groff_out(5).
In addition, the device and font description files for the device used must meet certain requirements. The device and font description files supplied for ps device meet all these requirements. afmtodit(1) can be used to create font files from AFM files. The resolution must be an integer multiple of~72 times the sizescale. The ps device uses a resolution of 72000 and a sizescale of 1000.
The device description file must contain a valid paper size; see groff_font(5) for more information.
Each font description file must contain a command
which says that the PostScript name of the font is psname. It may also contain a command
which says that the PostScript font should be reencoded using the encoding described in enc_file; this file should consist of a sequence of lines of the form:
where pschar is the PostScript name of the character, and code is its position in the encoding expressed as a decimal integer; valid values are in the range 0 to~255. Lines starting with # and blank lines are ignored. The code for each character given in the font file must correspond to the code for the character in encoding file, or to the code in the default encoding for the font if the PostScript font is not to be reencoded. This code can be used with the [rs]N escape sequence in troff to select the character, even if the character does not have a groff name. Every character in the font file must exist in the PostScript font, and the widths given in the font file must match the widths used in the PostScript font. grops will assume that a character with a groff name of space is blank (makes no marks on the page); it can make use of such a character to generate more efficient and compact PostScript output.
Note that grops is able to display all glyphs in a PostScript font, not only 256. enc_file (or the default encoding if no encoding file specified) just defines the order of glyphs for the first 256 characters; all other glyphs are accessed with additional encoding vectors which grops produces on the fly.
grops can automatically include the downloadable fonts necessary to print the document. Such fonts must be in PFA format. Use pfbtops(1) to convert a Type~1 font in PFB format. Any downloadable fonts which should, when required, be included by grops must be listed in the file /usr/share/groff_font/devps/download; this should consist of lines of the form
where font is the PostScript name of the font, and filename is the name of the file containing the font; lines beginning with # and blank lines are ignored; fields may be separated by tabs or spaces; filename will be searched for using the same mechanism that is used for groff font metric files. The download file itself will also be searched for using this mechanism; currently, only the first found file in the font path is used.
If the file containing a downloadable font or imported document conforms to the Adobe Document Structuring Conventions, then grops will interpret any comments in the files sufficiently to ensure that its own output is conforming. It will also supply any needed font resources that are listed in the download file as well as any needed file resources. It is also able to handle inter-resource dependencies. For example, suppose that you have a downloadable font called Garamond, and also a downloadable font called Garamond-Outline which depends on Garamond (typically it would be defined to copy Garamonds font dictionary, and change the PaintType), then it is necessary for Garamond to appear before Garamond-Outline in the PostScript document. grops will handle this automatically provided that the downloadable font file for Garamond-Outline indicates its dependence on Garamond by means of the Document Structuring Conventions, for example by beginning with the following lines
%!PS-Adobe-3.0 Resource-Font %%DocumentNeededResources: font Garamond %%EndComments %%IncludeResource: font Garamond
In this case both Garamond and Garamond-Outline would need to be listed in the download file. A downloadable font should not include its own name in a %%Document Supplied Resources comment.
grops will not interpret %%Document Fonts comments. The %%Document Needed Resources, %%Document Supplied Resources, %%Include Resource, %%Begin Resource, and %%End Resource comments (or possibly the old %%Document Needed Fonts, %%Document Supplied Fonts, %%Include Font, %%Begin Font, and %%End Font comments) should be used.