# phpman > man > Test::Builder::IO::Scalar ## NAME [Test::Builder::IO::Scalar](https://www.chedong.com/phpMan.php/perldoc/Test%3A%3ABuilder%3A%3AIO%3A%3AScalar/markdown) - A copy of [IO::Scalar](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AScalar/markdown) for [Test::Builder](https://www.chedong.com/phpMan.php/perldoc/Test%3A%3ABuilder/markdown) ## DESCRIPTION This is a copy of [IO::Scalar](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AScalar/markdown) which ships with [Test::Builder](https://www.chedong.com/phpMan.php/perldoc/Test%3A%3ABuilder/markdown) to support scalar references as filehandles on Perl 5.6. Newer versions of Perl simply use "open()"'s built in support. [Test::Builder](https://www.chedong.com/phpMan.php/perldoc/Test%3A%3ABuilder/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AHandle/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AScalar/markdown) will not work prior to 5.005_57. [IO::Scalar](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AScalar/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AScalar/markdown) 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 (). ### Principal author Eryq (). President, ZeeGee Software Inc (). ### Other contributors The full set of contributors always includes the folks mentioned in "CHANGE LOG" in [IO::Stringy](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AStringy/markdown). 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](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AHandle/markdown) inheritance and automatic tie-ing. ## SEE ALSO [IO::String](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AString/markdown), which is quite similar but which was designed more-recently and with an [IO::Handle](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AHandle/markdown)-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](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AHandle/markdown) counterparts, so we have comparable functionality to [IO::String](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AString/markdown).