Document Unix command-line options.

[originally from svn r6423]

puzzles.but

@@ -111,12 +111,14 @@ had done before saving).
 
 }
 
-\dt \ii\e{Print}
+\dt \I{printing, on Windows}\e{Print}
 
 \dd Where supported (currently only on Windows), brings up a dialog
 allowing you to print an arbitrary number of puzzles randomly
 generated from the current parameters, optionally including the
-current puzzle.
+current puzzle. (Only for puzzles which make sense to print, of
+course - it's hard to think of a sensible printable representation
+of Fifteen!)
 
 \dt \ii\e{Undo} (\q{U}, Ctrl+\q{Z}, Ctrl+\q{_})
 
@@ -302,6 +304,83 @@ than by pasting it into the game ID selection box.
 then some options, such as the difficulty level in Solo, will be
 missing. See \k{common-id} for more details on this.)
 
+\H{common-unix-cmdline} Unix \i{command-line} options
+
+(This section only applies to the Unix port.)
+
+In addition to specifying game parameters on the command line (see
+\k{common-cmdline}), you can also specify various options:
+
+\dt \cw{--generate }\e{n}
+
+\dd If this option is specified, instead of a puzzle being displayed,
+a number of descriptive game IDs will be invented and printed on
+standard output. This is useful for gaining access to the game
+generation algorithms without necessarily using the frontend.
+
+\lcont{
+
+If game parameters are specified on the command-line, they will be
+used to generate the game IDs; otherwise a default set of parameters
+will be used.
+
+The most common use of this option is in conjunction with \c{--print},
+in which case its behaviour is slightly different; see below.
+
+}
+
+\dt \I{printing, on Unix}\cw{--print }\e{w}\cw{x}\e{h}
+
+\dd If this option is specified, instead of a puzzle being displayed,
+a printed representation of one or more unsolved puzzles is sent to
+standard output, in \i{PostScript} format.
+
+\lcont{
+
+On each page of puzzles, there will be \e{w} across and \e{h} down. If
+there are more puzzles than \e{w}\by\e{h}, more than one page will be
+printed.
+
+If \c{--generate} has also been specified, the invented game IDs will
+be used to generate the printed output. Otherwise, a list of game IDs
+is expected on standard input (which can be descriptive or random
+seeds; see \k{common-id}), in the same format produced by
+\c{--generate}.
+
+For example:
+
+\c net --generate 12 --print 2x3 7x7w | lpr
+
+will generate two pages of printed Net puzzles (each of which will
+have a 7\by\.7 wrapping grid), and pipe the output to the \c{lpr}
+command, which on many systems will send them to an actual printer.
+
+There are various other options which affect printing; see below.
+
+}
+
+\dt \cw{--version}
+
+\dd Prints version information about the game, and then quits.
+
+The following options are only meaningful if \c{--print} is also
+specified:
+
+\dt \cw{--with-solutions}
+
+\dd The set of pages filled with unsolved puzzles will be followed by
+the solutions to those puzzles.
+
+\dt \cw{--scale }\e{n}
+
+\dd Adjusts how big each puzzle is when printed. Larger numbers make
+puzzles bigger; the default is 1.0.
+
+\dt \cw{--colour}
+
+\dd Puzzles will be printed in colour, rather than in black and white
+(if supported by the puzzle).
+
 
 \C{net} \i{Net}
 
@@ -2014,6 +2093,8 @@ ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 
+\IM{command-line}{command line} command line
+
 \IM{specific} \q{Specific}, menu option
 \IM{custom} \q{Custom}, menu option