Add a new warning, "Newline in left-justified string for printf/sprintf"

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

diff --git a/pod/perlrun.pod b/pod/perlrun.pod
index e6c8f73..85d3bdf 100644 (file)
--- a/pod/perlrun.pod
+++ b/pod/perlrun.pod
@@ -918,6 +918,8 @@ emphasise their similarity to variable "attributes". But the code that parses
 layer specification strings (which is also used to decode the PERLIO
 environment variable) treats the colon as a separator.
 
+An unset or empty PERLIO is equivalent to C<:stdio>.
+
 The list becomes the default for I<all> perl's IO. Consequently only built-in
 layers can appear in this list, as external layers (such as :encoding()) need
 IO in  order to load them!. See L<"open pragma"|open> for how to add external
@@ -930,8 +932,9 @@ variable are summarised below. For more details see L<PerlIO>.
 
 =item :bytes
 
-Turns I<off> the C<:utf8> flag for the layer below.
-Unlikely to be useful in global PERLIO environment variable.
+A pseudolayer that turns I<off> the C<:utf8> flag for the layer below.
+Unlikely to be useful on its own in the global PERLIO environment variable.
+You perhaps were thinking of C<:crlf:bytes> or C<:perlio:bytes>.
 
 =item :crlf
 
@@ -962,12 +965,17 @@ and in general attempts to minimize data copying.
 
 C<:perlio> will insert a C<:unix> layer below itself to do low level IO.
 
+=item :pop
+
+An experimental pseudolayer that removes the topmost layer.
+Use with the same care as is reserved for nitroglyserin.
+
 =item :raw
 
-Applying the <:raw> layer is equivalent to calling C<binmode($fh)>.
-It makes the stream pass each byte as-is without any translation.
-In particular CRLF translation, and/or :utf8 intuited from locale
-are disabled.
+A pseudolayer that manipulates other layers.  Applying the <:raw>
+layer is equivalent to calling C<binmode($fh)>.  It makes the stream
+pass each byte as-is without any translation.  In particular CRLF
+translation, and/or :utf8 intuited from locale are disabled.
 
 Arranges for all accesses go straight to the lowest buffered layer provided
 by the configration. That is it strips off any layers above that layer.
@@ -996,12 +1004,13 @@ C<open(), read(), write(), lseek(), close()>
 
 =item :utf8
 
-Turns on a flag on the layer below to tell perl that data sent to the
-stream should be converted to perl internal "utf8" form and that data from the
-stream should be considered as so encoded. On ASCII based platforms the
-encoding is UTF-8 and on EBCDIC platforms UTF-EBCDIC.
-May be useful in PERLIO environment variable to make UTF-8 the
-default. (To turn off that behaviour use C<:bytes> layer.)
+A pseudolayer that turns on a flag on the layer below to tell perl
+that data sent to the stream should be converted to perl internal
+"utf8" form and that data from the stream should be considered as so
+encoded. On ASCII based platforms the encoding is UTF-8 and on EBCDIC
+platforms UTF-EBCDIC.  May be useful in PERLIO environment variable to
+make UTF-8 the default. (To turn off that behaviour use C<:bytes>
+layer.)
 
 =item :win32
 
@@ -1059,7 +1068,7 @@ The command used to load the debugger code.  The default is:
 =item PERL5SHELL (specific to the Win32 port)
 
 May be set to an alternative shell that perl must use internally for
-executing "backtick" commands or system().  Default is C<cmd.exe /x/c>
+executing "backtick" commands or system().  Default is C<cmd.exe /x/d/c>
 on WindowsNT and C<command.com /c> on Windows95.  The value is considered
 to be space-separated.  Precede any character that needs to be protected
 (like a space or backslash) with a backslash.