proof – troff output interpreter
intermediate language from
or standard input
and simulates the resulting pages on the screen.
After a page of text is displayed,
pauses for a command from the keyboard.
The typed commands are:
Go on to next page of text.
Go back to the previous page.
An out-of-bounds page number means the end nearer to that number;
a missing number means the current page;
a signed number means an offset to the current page.
Clear the screen, then wait for another command.
Change the magnification at which the output is printed.
Normally it is printed with magnification .9;
shrinks it to half size;
doubles the size.
screen pixels to the right (left, if
screen pixels down (up, if
Split the window into
pieces. The current page goes into the rightmost, bottommost piece,
and previous pages are shown in the other pieces.
for fonts instead of
Toggle the debug flag.
These commands are also available, under slightly different form,
from a menu on button 3. The
menu item allows arbitrary positioning of the page:
press the mouse button again and hold it down while moving
the page to the desired location. The page will be redisplayed
in its entirety when the button is released.
Mouse button 1 also pans, without the need for selecting from a menu.
commands are also available as command line options.
how to convert troff output fonts and character names
into screen fonts and character numbers
J. F. Ossanna and B. W. Kernighan,
“Troff User’s Manual”