GROFF_OUTSection: File Formats (5)
Updated: 06 April 2001
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NAMEgroff_out - groff intermediate output format
DESCRIPTIONThis manual page describes the format output by GNU troff. The output format used by GNU troff is very similar to that used by Unix device-independent troff. Only the differences are documented here.
The argument to the s command is in scaled points (units of points/n, where n is the argument to the sizescale command in the DESC file.) The argument to the x Height command is also in scaled points.
The first three output commands are guaranteed to be:
If the tcommand line is present in the DESC file, troff will use the following two commands
Note that single characters can have the eighth bit set, as can the names of fonts and special characters.
The names of characters and fonts can be of arbitrary length; drivers should not assume that they will be only two characters long.
When a character is to be printed, that character will always be in the current font. Unlike device-independent troff, it is not necessary for drivers to search special fonts to find a character.
The x device control command has been extended.
The D drawing command has been extended. These extensions will not be used by GNU pic if the -n option is given.
A difficulty arises in how the current position should be changed after the execution of these commands. This is not of great importance since the code generated by GNU pic does not depend on this. Given a drawing command of the form
where c is not one of c, e, l, a or ~, Unix troff will treat each of the $x sub i$ as a horizontal quantity, and each of the $y sub i$ as a vertical quantity and will assume that the width of the drawn object is $sum from i=1 to n x sub i$, and that the height is $sum from i=1 to n y sub i$. (The assumption about the height can be seen by examining the st and sb registers after using such a D command in a \w escape sequence.) This rule also holds for all the original drawing commands with the exception of De. For the sake of compatibility GNU troff also follows this rule, even though it produces an ugly result in the case of the Df, Dt, and, to a lesser extent, DE commands. Thus after executing a D command of the form
the current position should be increased by $( sum from i=1 to n x sub i , sum from i=1 to n y sub i )$.
There is a continuation convention which permits the argument to the x X command to contain newlines: when outputting the argument to the x X command, GNU troff will follow each newline in the argument with a + character (as usual, it will terminate the entire argument with a newline); thus if the line after the line containing the x X command starts with +, then the newline ending the line containing the x X command should be treated as part of the argument to the x X command, the + should be ignored, and the part of the line following the + should be treated like the part of the line following the x X command.
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Time: 04:17:58 GMT, February 26, 2024