From: Jarkko Hietaniemi <jhi@iki.fi>
Date: Tue, 26 Aug 2003 08:54:02 +0000 (+0000)
Subject: PerlIO on EBCDIC on BS2000 advice from Thomas Dorner.
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=756189a56ad5859c77093ea1770647e4355c6aeb;p=p5sagit%2Fp5-mst-13.2.git

PerlIO on EBCDIC on BS2000 advice from Thomas Dorner.
(This information looks interesting enough to be mentioned
elsewhere, too.)

p4raw-id: //depot/perl@20903
---

diff --git a/README.bs2000 b/README.bs2000
index 1a0f5b7..a7746c6 100644
--- a/README.bs2000
+++ b/README.bs2000
@@ -174,6 +174,40 @@ Perl code:
 Although one would expect the quantities $y and $z to be the same and equal
 to 100000 they will differ and instead will be 0 and 100000 respectively.
 
+=head2 Using PerlIO and different encodings on ASCII and EBCDIC partitions
+
+Since version 5.8 Perl uses the new PerlIO on BS2000.  This enables
+you using different encodings per IO channel.  For example you may use
+
+    use Encode;
+    open($f, ">:encoding(ascii)", "test.ascii");
+    print $f "Hello World!\n";
+    open($f, ">:encoding(posix-bc)", "test.ebcdic");
+    print $f "Hello World!\n";
+    open($f, ">:encoding(latin1)", "test.latin1");
+    print $f "Hello World!\n";
+    open($f, ">:encoding(utf8)", "test.utf8");
+    print $f "Hello World!\n";
+
+to get two files containing "Hello World!\n" in ASCII, EBCDIC, ISO
+Latin-1 (in this example identical to ASCII) respective UTF-EBCDIC (in
+this example identical to normal EBCDIC).  See the documentation of
+Encode::PerlIO for details.
+
+As the PerlIO layer uses raw IO internally, all this totally ignores
+the type of your filesystem (ASCII or EBCDIC) and the IO_CONVERSION
+environment variable.  If you want to get the old behavior, that the
+BS2000 IO functions determine conversion depending on the filesystem
+PerlIO still is your friend.  You use IO_CONVERSION as usual and tell
+Perl, that it should use the native IO layer:
+
+    export IO_CONVERSION=YES
+    export PERLIO=stdio
+
+Now your IO would be ASCII on ASCII partitions and EBCDIC on EBCDIC
+partitions.  See the documentation of PerlIO (without C<Encode::>!)
+for further posibilities.
+
 =head1 AUTHORS
 
 Thomas Dorner