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8.172. PerlIO::Via
A
helper class for PerlIO layers implemented in Perl. PerlIO::Via ships
with the Perl 5.8 source kit.
For example, you can use PerlIO::Via to call
MIME::Base64::encode_base64() via
open():
#!/usr/local/bin/perl -w;
use MIME::Base64;
open(my $fh, ">Via(MIME::Base64)", "encode_base64");
PerlIO::Via implements the following methods.
| CLOSE |
CLOSE(fh)
Returns 0 on success and -1 on
error.
| EOF |
EOF(fh)
Returns end-of-file state. The default behavior is to return a value
of FILL() or READ().
| ERROR |
ERROR(fh)
Returns error state.
| FILENO |
FILENO(fh)
Returns a numeric value that represents the Unix-like file
descriptor, or -1 if no file descriptor exists.
| FILL |
FILL(fh)
Returns a string that will be placed in the buffer.
| FLUSH |
FLUSH(fh)
Flushes any buffered write data. Returns 0 on
success and -1 on error.
| POPPED |
POPPED([fh])
Removes a layer from PerlIO::Via.
| PUSHED |
$class->PUSHED([mode [,fh]])
Returns an object or the class, or -1 on failure.
PUSHED takes optional arguments for file open
mode—r, w,
w+, etc.—and takes a mandatory filehandle
for the PerlIO layer itself.
| READ |
READ(buffer, len, fh)
Returns the number of octets in buffer,
which must be less than or equal to len.
| SEEK |
SEEK(posn, where, fh)
Returns 0 on success and -1 on
error.
| TELL |
TELL(fh)
Returns the file position, without an available default.
| UNREAD |
UNREAD(buffer, fh)
Returns the number of octets from bufferthat have been successfully saved.
| WRITE |
WRITE(buffer, fh)
Returns the number of octets in buffer that have been
written.
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| 8.171. PerlIO::Scalar | ![]() | 8.173. Pod::Functions |

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