Support leading, trailing and double colons in MANPATH to prepend,

append or insert the man.conf(5) default path; compatible with GNU
manpath(1), implementation by kristaps@, heavily tweaked by schwarze@.

Updates to MANPATH documentation applied to whatis.1, apropos.1, and
catman.8 also.

1 files changed, 12 insertions, 1 deletions

diff --git a/catman.8 b/catman.8
index 333d13be..a57716e7 100644
--- a/catman.8
+++ b/catman.8
@@ -80,11 +80,22 @@ is specified, all files are updated.
 .Sh ENVIRONMENT
 .Bl -tag -width Ds
 .It Ev MANPATH
-Colon-separated paths overriding the default list of paths searched for
+Colon-separated paths modifying the default list of paths searched for
 manual databases.
 Invalid paths, or paths without manual databases, are ignored.
 Overridden by
 .Fl M .
+If
+.Ev MANPATH
+begins with a
+.Sq \&: ,
+it is appended to the default list;
+else if it ends with
+.Sq \&: ,
+it is prepended to the default list; else if it contains
+.Sq \&:: ,
+the default list is inserted between the colons.
+If none of these conditions are met, it overrides the default list.
 .El
 .Sh EXIT STATUS
 .Ex -std