TROFF(7)                                                 TROFF(7)

     NAME
          troff - addenda to troff manual

     DESCRIPTION
          These addenda apply to the reference.

          New requests; none cause breaks:

          .ab t     print text t on standard error and stop
          .cf f     copy file f into troff output uninterpreted;
               assume net motion is 0
          .sy c     execute unix comand c
          .pi c     pipe output of troff through command c

          Deleted request:

          .li

          New escape sequences

          \D'l dh dv'
               draw line dh horizontally and dv vertically
          \D'c d'
               draw circle with diameter d extending right from cur-
               rent position
          \D'e h v' draw ellipse with axis
               h extending right from current position and vertical
               axis v
          \D'a dh1 dv1 dh2 dv2'
               arc counterclockwise from here, centered at dh1,dv1 to
               dh1+dh2,dv1+dv2
          \D'≈ dh1 dv1 dh2 dv2 ...' quadratic spline
          \gr or \g(rr
               format of number register r or rr; empty if not defined
          \H'n'
               character height of present font is n points, width
               unchanged; n=0 for present point size; +n increments;
               -n decrements
          \S'n'
               slant output n degrees; n may be negative

          New number registers:

          $$   process id of troff; read only
          .L   line spacing (.ls); read only
          .P   1 if page is being printed; 0 if suppressed by -o; read
               only
          .R   number of unused number registers
          .b   emboldening factor (.bd)
          .j   .ad setting, usable as argument to .ad

     TROFF(7)                                                 TROFF(7)

          .k   horizontal size of text (excluding indent) of current
               partial output line
          c.   input line-number, counting from 1 in each file; same
               as .c, but writable
          .T   troff output device name (a string: \*(.T)

          Number register deleted:

          hp

     SEE ALSO
          J. F. Ossanna, NROFF/TROFF Reference Manual
          troff(1)