GNU Info

(groff)Suppressing output

---

Next: I/O Prev: Environments Up: gtroff Reference

---

Enter node , (file) or (file)node

Suppressing output
==================

 - Escape: \ONUM
     Disables or enables output depending on the value of NUM:

    `\O0'
          Disable any ditroff glyphs from being emitted to the device
          driver.

    `\O1'
          Enable output of glyphs.

     `\O0' and `\O1' also reset the four registers `opminx', `opminy',
     `opmaxx', and `opmaxy' to -1.  Note: Register Index.  These four
     registers mark the top left and bottom right hand corners of a box
     which encompasses all written glyphs.

     The following two forms of `\O' are specific to `grohtml'.

    `\O2'
          Disable any ditroff glyphs from being emitted to the device
          driver.  Also write out to `stderr' the page number and four
          registers encompassing the glyphs previously written since
          the last call to `\O'.

    `\O3'
          Enable output of glyphs (the default).  Also write out to
          `stderr' the page number and four registers encompassing the
          glyphs previously written since the last call to `\O'.