Re: 20001101.003 PDL

[p5sagit/p5-mst-13.2.git] / pod / perlvar.pod

diff --git a/pod/perlvar.pod b/pod/perlvar.pod
index 15308e4..49cdcb2 100644 (file)
--- a/pod/perlvar.pod
+++ b/pod/perlvar.pod
@@ -619,7 +619,8 @@ across fork() calls.  (Mnemonic: same as shells.)
 =item $<
 
 The real uid of this process.  (Mnemonic: it's the uid you came I<from>,
-if you're running setuid.)
+if you're running setuid.)  You can change both the real uid and
+the effective uid at the same time by using POSIX::setuid().
 
 =item $EFFECTIVE_USER_ID
 
@@ -632,6 +633,9 @@ The effective uid of this process.  Example:
     $< = $>;           # set real to effective uid
     ($<,$>) = ($>,$<); # swap real and effective uid
 
+You can change both the effective uid and the real uid at the same
+time by using POSIX::setuid().
+
 (Mnemonic: it's the uid you went I<to>, if you're running setuid.)
 C<< $< >> and C<< $> >> can be swapped only on machines
 supporting setreuid().
@@ -652,6 +656,9 @@ However, a value assigned to C<$(> must be a single number used to
 set the real gid.  So the value given by C<$(> should I<not> be assigned
 back to C<$(> without being forced numeric, such as by adding zero.
 
+You can change both the real gid and the effective gid at the same
+time by using POSIX::setgid().
+
 (Mnemonic: parentheses are used to I<group> things.  The real gid is the
 group you I<left>, if you're running setgid.)
 
@@ -674,6 +681,9 @@ empty list for setgroups(), just repeat the new effective gid; that is,
 to force an effective gid of 5 and an effectively empty setgroups()
 list, say C< $) = "5 5" >.
 
+You can change both the effective gid and the real gid at the same
+time by using POSIX::setgid() (use only a single numeric argument).
+
 (Mnemonic: parentheses are used to I<group> things.  The effective gid
 is the group that's I<right> for you, if you're running setgid.)
 
@@ -691,6 +701,11 @@ program sees.  This is more useful as a way of indicating the current
 program state than it is for hiding the program you're running.
 (Mnemonic: same as B<sh> and B<ksh>.)
 
+Note for BSD users: setting C<$0> does not completely remove "perl"
+from the ps(1) output.  For example, setting C<$0> to C<"foobar"> will
+result in C<"perl: foobar (perl)">.  This is an operating system
+feature.
+
 =item $[
 
 The index of the first element in an array, and of the first character
@@ -821,7 +836,7 @@ Then
 would allocate a 64K buffer for use in an emergency.  See the
 F<INSTALL> file in the Perl distribution for information on how to
 enable this option.  To discourage casual use of this advanced
-feature, there is no L<English> long name for this variable.
+feature, there is no L<English|English> long name for this variable.
 
 =item $OSNAME