Correct description of MANPATH, and a few more improvements

to the ENVIRONMENT section; OK jmc@

1 files changed, 26 insertions, 7 deletions

diff --git a/man.1 b/man.1
index 116c6dde..603a478f 100644
--- a/man.1
+++ b/man.1
@@ -1,4 +1,4 @@
-.\"	$Id: man.1,v 1.22 2017/03/17 17:24:41 schwarze Exp $
+.\"	$Id: man.1,v 1.23 2017/03/18 19:51:19 schwarze Exp $
 .\"
 .\" Copyright (c) 1989, 1990, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -31,7 +31,7 @@
 .\"
 .\"     @(#)man.1	8.2 (Berkeley) 1/2/94
 .\"
-.Dd $Mdocdate: March 17 2017 $
+.Dd $Mdocdate: March 18 2017 $
 .Dt MAN 1
 .Os
 .Sh NAME
@@ -322,7 +322,7 @@ is case insensitive.
 .It Ev MANPAGER
 Any non-empty value of the environment variable
 .Ev MANPAGER
-will be used instead of the standard pagination program,
+is used instead of the standard pagination program,
 .Xr more 1 .
 If
 .Xr less 1
@@ -346,13 +346,27 @@ information about the term last searched for with
 .It Ev MANPATH
 The standard search path used by
 .Nm
-may be overridden by specifying a path in the
+may be changed by specifying a path in the
 .Ev MANPATH
-environment
-variable.
+environment variable.
 The format of the path is a colon
 .Pq Ql \&:
 separated list of directories.
+Invalid paths, or paths without manual databases, are ignored.
+Overridden by
+.Fl M ,
+ignored if
+.Fl l
+is specified.
+.Pp
+If
+.Ev MANPATH
+begins with a colon, it is appended to the default list;
+if it ends with a colon, it is prepended to the default list;
+or if it contains two adjacent colons,
+the standard search path is inserted between the colons.
+If none of these conditions are met, it overrides the
+standard search path.
 .It Ev PAGER
 Specifies the pagination program to use when
 .Ev MANPAGER
@@ -360,7 +374,12 @@ is not defined.
 If neither PAGER nor MANPAGER is defined,
 .Xr more 1
 .Fl s
-will be used.
+is used.
+Only used if
+.Fl a
+or
+.Fl l
+is specified.
 .El
 .Sh FILES
 .Bl -tag -width /etc/man.conf -compact