Test::Builder::IO::Scalar(3pm) Perl Programmers Reference Guide
NAME
Test::Builder::IO::Scalar - A copy of IO::Scalar for Test::Builder
DESCRIPTION
This is a copy of IO::Scalar which ships with Test::Builder to support
scalar references as filehandles on Perl 5.6. Newer versions of Perl
simply use open()'s built in support.
Test::Builder can not have dependencies on other modules without
careful consideration, so its simply been copied into the distribution.
COPYRIGHT and LICENSE
This file came from the "IO-stringy" Perl5 toolkit.
Copyright (c) 1996 by Eryq. All rights reserved. Copyright (c)
1999,2001 by ZeeGee Software Inc. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
Construction
new [ARGS...]
Class method. Return a new, unattached scalar handle. If any
arguments are given, they're sent to open().
open [SCALARREF]
Instance method. Open the scalar handle on a new scalar, pointed to
by SCALARREF. If no SCALARREF is given, a "private" scalar is
created to hold the file data.
Returns the self object on success, undefined on error.
opened
Instance method. Is the scalar handle opened on something?
close
Instance method. Disassociate the scalar handle from its underlying
scalar. Done automatically on destroy.
Input and output
flush
Instance method. No-op, provided for OO compatibility.
getc
Instance method. Return the next character, or undef if none
remain.
getline
Instance method. Return the next line, or undef on end of string.
Can safely be called in an array context. Currently, lines are
delimited by "\n".
getlines
Instance method. Get all remaining lines. It will croak() if
accidentally called in a scalar context.
print ARGS...
Instance method. Print ARGS to the underlying scalar.
Warning: this continues to always cause a seek to the end of the
string, but if you perform seek()s and tell()s, it is still safer
to explicitly seek-to-end before subsequent print()s.
read BUF, NBYTES, [OFFSET]
Instance method. Read some bytes from the scalar. Returns the
number of bytes actually read, 0 on end-of-file, undef on error.
write BUF, NBYTES, [OFFSET]
Instance method. Write some bytes to the scalar.
sysread BUF, LEN, [OFFSET]
Instance method. Read some bytes from the scalar. Returns the
number of bytes actually read, 0 on end-of-file, undef on error.
syswrite BUF, NBYTES, [OFFSET]
Instance method. Write some bytes to the scalar.
Seeking/telling and other attributes
autoflush
Instance method. No-op, provided for OO compatibility.
binmode
Instance method. No-op, provided for OO compatibility.
clearerr
Instance method. Clear the error and EOF flags. A no-op.
eof Instance method. Are we at end of file?
seek OFFSET, WHENCE
Instance method. Seek to a given position in the stream.
sysseek OFFSET, WHENCE
Instance method. Identical to "seek OFFSET, WHENCE", q.v.
tell
Instance method. Return the current position in the stream, as a
numeric offset.
use_RS [YESNO]
Instance method. Deprecated and ignored. Obey the current setting
of $/, like IO::Handle does? Default is false in 1.x, but cold-
welded true in 2.x and later.
setpos POS
Instance method. Set the current position, using the opaque value
returned by getpos().
getpos
Instance method. Return the current position in the string, as an
opaque object.
sref
Instance method. Return a reference to the underlying scalar.
WARNINGS
Perl's TIEHANDLE spec was incomplete prior to 5.005_57; it was missing
support for seek(), tell(), and eof(). Attempting to use these
functions with an IO::Scalar will not work prior to 5.005_57.
IO::Scalar will not have the relevant methods invoked; and even worse,
this kind of bug can lie dormant for a while. If you turn warnings on
(via $^W or "perl -w"), and you see something like this...
attempt to seek on unopened filehandle
...then you are probably trying to use one of these functions on an
IO::Scalar with an old Perl. The remedy is to simply use the OO
version; e.g.:
$SH->seek(0,0); ### GOOD: will work on any 5.005
seek($SH,0,0); ### WARNING: will only work on 5.005_57 and beyond
VERSION
$Id: Scalar.pm,v 1.6 2005/02/10 21:21:53 dfs Exp $
AUTHORS
Primary Maintainer
David F. Skoll (dfs@roaringpenguin.com).
Principal author
Eryq (eryq@zeegee.com). President, ZeeGee Software Inc
(http://www.zeegee.com).
Other contributors
The full set of contributors always includes the folks mentioned in
"CHANGE LOG" in IO::Stringy. But just the same, special thanks to the
following individuals for their invaluable contributions (if I've
forgotten or misspelled your name, please email me!):
Andy Glew, for contributing getc().
Brandon Browning, for suggesting opened().
David Richter, for finding and fixing the bug in PRINTF().
Eric L. Brine, for his offset-using read() and write() implementations.
Richard Jones, for his patches to massively improve the performance of
getline() and add "sysread" and "syswrite".
B. K. Oxley (binkley), for stringification and inheritance
improvements, and sundry good ideas.
Doug Wilson, for the IO::Handle inheritance and automatic tie-ing.
SEE ALSO
IO::String(3), which is quite similar but which was designed more-
recently and with an IO::Handle-like interface in mind, so you could mix
OO- and native-filehandle usage without using tied().
Note: as of version 2.x, these classes all work like their IO::Handle
counterparts, so we have comparable functionality to IO::String.
perl v5.38.2 2023-11-28 Test::Builder::IO::Scalar(3pm)
perl 5.38.2 - Generated Fri Dec 13 14:50:50 CST 2024