Implement the roff(7) .ll (line length) request.

Found by naddy@ in the textproc/enchant(1) port.
Of course, do not use this in new manuals.

1 files changed, 15 insertions, 0 deletions

diff --git a/roff.7 b/roff.7
index d557a2e8..7a60cf30 100644
--- a/roff.7
+++ b/roff.7
@@ -874,6 +874,21 @@ Otherwise, it only terminates the
 and arguments following it or the
 .Sq \&..
 request are discarded.
+.Ss \&ll
+Change the output line length.
+Its syntax is as follows:
+.Pp
+.D1 Pf . Cm \&ll Op Ar width
+.Pp
+If the
+.Ar width
+argument is omitted, the line length is reset to its previous value.
+The default setting for terminal output is 78n.
+Using this request in new manuals is discouraged for several reasons,
+among others because it overrides the
+.Xr mandoc 1
+.Fl O Cm width
+command line option.
 .Ss \&ne
 Declare the need for the specified minimum vertical space
 before the next trap or the bottom of the page.