Teach portsnap how to ignore unwanted parts of the ports tree. A line

of the form "REFUSE foo" in portsnap.conf will result in parts of the
tree matching "^foo" being (a) not extracted by "portsnap extract", (b)
not updated by "portsnap update", and (c) not having any patches or new
ports downloaded by "portsnap fetch" or "portsnap cron". The example
shown in portsnap.conf demonstrates ignoring all the language categories.

As mentioned in portsnap.conf.5, the use of an imcomplete ports tree is
not officially supported; but this is something which many users have
requested, so I'm adding it anyway.

PR:		bin/85619 (but not the patch provided therein)
MFC after:	1 month

1 files changed, 36 insertions, 2 deletions

diff --git a/share/man/man5/portsnap.conf.5 b/share/man/man5/portsnap.conf.5
index eeae1f1..ba632166 100644
--- a/share/man/man5/portsnap.conf.5
+++ b/share/man/man5/portsnap.conf.5
@@ -87,14 +87,48 @@ is used.
 .Pp
 If more than one line of any of the above forms is included in
 .Nm
-then only the last one will take effect.  Any lines not of the above
-forms will be ignored.
+then only the last one will take effect.
+.Pp
+Finally, a line of the form
+.Dl REFUSE foo bar
+will instruct
+.Xr portsnap 8
+to ignore parts of the ports tree with paths starting with
+.Ar foo 
+or
+.Ar bar ,
+which are interpreted as extended regular expressions by
+.Xr egrep 1 .
+This will result in those parts of the tree not being updated
+in the compressed snapshot when the
+.Cm fetch
+and
+.Cm cron
+commands are used and not being extracted when the
+.Cm extract
+command is used (unless a specific
+.Ar path
+is passed to
+.Xr portsnap 8 ) ,
+and if those parts of the ports tree are present they
+will not be updated when the
+.Cm update
+command is used.
+Unlike the other options, the parameters in REFUSE lines
+accumulate and all such lines are considered.
+.Bf Em
+Note that operating with an incomplete ports tree is not
+supported and may cause unexpected results.
+.Ef
+.Pp
+Any lines not of the above forms will be ignored.
 .Sh FILES
 .Bl -tag -width "/etc/portsnap.conf"
 .It /etc/portsnap.conf
 Default location of the portsnap configuration file.
 .El
 .Sh SEE ALSO
+.Xr egrep 1
 .Xr fetch 1
 .Xr portsnap 8
 .Xr sha256 8