=head1 SYNOPSIS
- open($fh,">:crlf","my.txt")
- open($fh,">:raw","his.jpg")
+ open($fh,">:crlf", "my.txt")
+ open($fh,">:bytes","his.jpg")
Shell:
PERLIO=perlio perl ....
=item raw
+B<Note that the explicit use of the C<raw> layer is deprecated.>
+
A pseudo-layer which performs two functions (which is messy, but
necessary to maintain compatibility with non-PerlIO builds of Perl
and their way things have been documented elsewhere).
=head1 SYNOPSIS
- use open IN => ":crlf", OUT => ":raw";
+ use open IN => ":crlf", OUT => ":bytes";
use open OUT => ':utf8';
use open IO => ":encoding(iso-8859-7)";
=head1 NONPERLIO FUNCTIONALITY
If Perl is not built to use PerlIO as its IO system then only the two
-pseudo-disciplines ":raw" and ":crlf" are available.
+pseudo-disciplines C<:bytes> and C<:crlf> are available.
-The ":raw" discipline corresponds to "binary mode" and the ":crlf"
+The C<:bytes> discipline corresponds to "binary mode" and the C<:crlf>
discipline corresponds to "text mode" on platforms that distinguish
between the two modes when opening files (which is many DOS-like
platforms, including Windows). These two disciplines are no-ops on
=item binmode FILEHANDLE
-Arranges for FILEHANDLE to be read or written in "binary" or "text" mode
-on systems where the run-time libraries distinguish between binary and
-text files. If FILEHANDLE is an expression, the value is taken as the
-name of the filehandle.
-
-DISCIPLINE can be either of C<:raw> for binary mode or C<:crlf> for
-"text" mode. If the DISCIPLINE is omitted, it defaults to C<:raw>.
-Returns true on success, C<undef> on failure. To mark FILEHANDLE as
-UTF-8, use C<:utf8>, and to mark it as bytes, use C<:bytes>.
-For backward compatibility binmode(FILEHANDLE) also implicitly
-marks the handle as bytes.
-
-The C<:raw> are C<:clrf>, and any other directives of the form
-C<:...>, are called I/O I<disciplines>. The C<open> pragma can be
-used to establish default I/O disciplines. See L<open>.
+Arranges for FILEHANDLE to be read or written in "binary" or "text"
+mode on systems where the run-time libraries distinguish between
+binary and text files. If FILEHANDLE is an expression, the value is
+taken as the name of the filehandle. Returns true on success,
+C<undef> on failure.
+
+DISCIPLINE can be either of C<:bytes> for "binary" mode or C<:crlf>
+for "text" mode. If the DISCIPLINE is omitted, it defaults to
+C<:bytes>. To mark FILEHANDLE as UTF-8, use C<:utf8>. For backward
+compatibility C<binmode(FILEHANDLE)> also implicitly marks the
+filehandle as bytes.
+
+The C<:bytes>, C<:crlf>, and C<:utf8>, and any other directives of the
+form C<:...>, are called I/O I<disciplines>. The C<open> pragma can
+be used to establish default I/O disciplines. See L<open>.
+
+The C<:raw> discipline is deprecated. (As opposed to what Camel III
+said, it is not the inverse of C<:crlf>.) See L<perlrun> and the
+discussion about the PERLIO environment variable.
In general, binmode() should be called after open() but before any I/O
is done on the filehandle. Calling binmode() will flush any possibly
The C<:encoding> discipline sometimes needs to be called in
mid-stream, and it doesn't flush the stream.
-On some systems binmode() is necessary when you're not working with a
-text file. For the sake of portability it is a good idea to always use
-it when appropriate, and to never use it when it isn't appropriate.
+On some systems (in general, DOS and Windows-based systems) binmode()
+is necessary when you're not working with a text file. For the sake
+of portability it is a good idea to always use it when appropriate,
+and to never use it when it isn't appropriate.
-In other words: Regardless of platform, use binmode() on binary
-files, and do not use binmode() on text files.
+In other words: regardless of platform, use binmode() on binary files
+(like for example images), and do not use binmode() on text files.
The operating system, device drivers, C libraries, and Perl run-time
system all work together to let the programmer treat a single
=item :raw
+B<Note that the explicit use of the C<:raw> layer is deprecated.>
+
Arranges for all accesses go straight to the lowest level layer provided
by the configration. That is it strips off any layers above that layer.
(The intent - unless layers are then pushed on top again -
is to make perl's C<read> behave like C<sysread>.)
-Not really useful in PERLIO environment variable, instead just use C<:unix>
-layer explicitly.
+Not really useful in PERLIO environment variable, instead just use
+C<:unix> layer explicitly.
-In perl5.6 and some books the C<:raw> layer (also called a discipline) is
-documented as the inverse of the C<:crlf> layer. That is not really the case.
-If you want UNIX line endings on a platform that normaly does CRLF translation
-the appropriate thing to do is to add C<:perlio> to PERLIO environment
-variable.
+In Perl 5.6 and some books the C<:raw> layer (also called a discipline)
+is documented as the inverse of the C<:crlf> layer. That is not really
+the case. If you want UNIX line endings on a platform that normally
+does CRLF translation the appropriate thing to do is to add C<:perlio>
+to PERLIO environment variable.
=item :stdio
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