The commands in this subsection have a command code consisting of a single character, taking a fixed number of arguments. Most of them are commands for positioning and text writing. These commands are smart about whitespace. Optionally,
syntactical space can be inserted before, after, and between the command letter and its arguments. All of these commands are stackable, i.e., they can be preceded by other simple commands or followed by arbitrary other commands on the same line. A separating
syntactical space is only necessary when two integer arguments would clash or if the preceding argument ends with a string argument. Open a new environment by copying the actual device configuration data to the environment stack. The current environment is setup by the device specification and manipulated by the setting commands. Close the actual environment (opened by a preceding
{ command) and restore the previous environment from the environment stack as the actual device configuration data. Print a special groff character named The trailing
syntactical space or
line break is necessary to allow character names of arbitrary length. The character is printed at the current print position; the character's size is read from the font file. The print position is not changed. Print character at the current print position; the character's size is read from the font file. The print position is not changed. Set font to font number (a non-negative integer). Move right to the absolute vertical position (a non-negative integer in basic units relative to left edge of current page. Move (a non-negative integer) basic units horizontally to the right.
[CSTR #54] allows negative values for
n also, but
groff doesn't use this. Set the color for text (glyphs), line drawing, and the outline of graphic objects using different color schemes; the analoguous command for the filling color of graphic objects is
DF. The color components are specified as integer arguments between 0 and n[@maxcolor]. The number of color components and their meaning vary for the different color schemes. These commands are generated by the
groff escape sequence
\m. No position changing. These commands are a
groff extension.
Set color using the CMY color scheme, having the 3 color components cyan, magenta, and yellow. Set color to the default color value (black in most cases). No component arguments. Set color to the shade of gray given by the argument, an integer between 0 (black) and n[@maxcolor] (white). Set color using the CMYK color scheme, having the 4 color components cyan, magenta, yellow, and black. Set color using the RGB color scheme, having the 3 color components red, green, and blue.
Print character with index (an integer, normally non-negative) of the current font. The print position is not changed. If
-T html is used, negative values are emitted also to indicate an unbreakable space with given width. For example,
N -193 represents an unbreakable space which has a width of 193u. This command is a
groff extension. Inform the device about a line break, but no positioning is done by this command. In
classical troff, the integer arguments and informed about the space before and after the current line to make the
intermediate output more human readable without performing any action. In
groff, they are just ignored, but they must be provided for compatibility reasons. Begin a new page in the outprint. The page number is set to This page is completely independent of pages formerly processed even if those have the same page number. The vertical position on the outprint is automatically set to 0. All positioning, writing, and drawing is always done relative to a page, so a
p command must be issued before any of these commands. Set point size to scaled points (this is unit in GNU
troff). Classical troff used the unit
points ( instead; see section
COMPATIBILITY. Print a word, i.e., a sequence of characters terminated by a space character or a line break; an optional second integer argument is ignored (this allows the formatter to generate an even number of arguments). The first character should be printed at the current position, the current horizontal position should then be increased by the width of the first character, and so on for each character. The widths of the characters are read from the font file, scaled for the current point size, and rounded to a multiple of the horizontal resolution. Special characters cannot be printed using this command (use the
C command for named characters). This command is a
groff extension; it is only used for devices whose
DESC file contains the
tcommand keyword; see
groff_font(5). Print word with track kerning. This is the same as the
t command except that after printing each character, the current horizontal position is increased by the sum of the width of that character and (an integer in basic units This command is a
groff extension; it is only used for devices whose
DESC file contains the
tcommand keyword; see
groff_font(5). Move down to the absolute vertical position (a non-negative integer in basic units relative to upper edge of current page. Move basic units down
(n is a non-negative integer).
[CSTR #54] allows negative values for
n also, but
groff doesn't use this. Informs about a paddable whitespace to increase readability. The spacing itself must be performed explicitly by a move command.