1Test::Builder::IO::ScalUasre(r3)Contributed Perl DocumenTteastti:o:nBuilder::IO::Scalar(3)
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6 Test::Builder::IO::Scalar - A copy of IO::Scalar for Test::Builder
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9 This is a copy of IO::Scalar which ships with Test::Builder to support
10 scalar references as filehandles on Perl 5.6. Newer versions of Perl
11 simply use "open()"'s built in support.
12 Test::Builder can not have dependencies on other modules without
14 careful consideration, so its simply been copied into the distribution.
15
17 This file came from the "IO-stringy" Perl5 toolkit.
18 Copyright (c) 1996 by Eryq. All rights reserved. Copyright (c)
20 1999,2001 by ZeeGee Software Inc. All rights reserved.
21 This program is free software; you can redistribute it and/or modify it
23 under the same terms as Perl itself.
24 Construction
26 new [ARGS...]
27 Class method. Return a new, unattached scalar handle. If any
28 arguments are given, they're sent to open().
29 open [SCALARREF]
31 Instance method. Open the scalar handle on a new scalar, pointed
32 to by SCALARREF. If no SCALARREF is given, a "private" scalar is
33 created to hold the file data.
34 Returns the self object on success, undefined on error.
36 opened
38 Instance method. Is the scalar handle opened on something?
39 close
41 Instance method. Disassociate the scalar handle from its
42 underlying scalar. Done automatically on destroy.
43 Input and output
45 flush
46 Instance method. No-op, provided for OO compatibility.
47 getc
49 Instance method. Return the next character, or undef if none
50 remain.
51 getline
53 Instance method. Return the next line, or undef on end of string.
54 Can safely be called in an array context. Currently, lines are
55 delimited by "\n".
56 getlines
58 Instance method. Get all remaining lines. It will croak() if
59 accidentally called in a scalar context.
60 print ARGS...
62 Instance method. Print ARGS to the underlying scalar.
63 Warning: this continues to always cause a seek to the end of the
65 string, but if you perform seek()s and tell()s, it is still safer
66 to explicitly seek-to-end before subsequent print()s.
67 read BUF, NBYTES, [OFFSET]
69 Instance method. Read some bytes from the scalar. Returns the
70 number of bytes actually read, 0 on end-of-file, undef on error.
71 write BUF, NBYTES, [OFFSET]
73 Instance method. Write some bytes to the scalar.
74 sysread BUF, LEN, [OFFSET]
76 Instance method. Read some bytes from the scalar. Returns the
77 number of bytes actually read, 0 on end-of-file, undef on error.
78 syswrite BUF, NBYTES, [OFFSET]
80 Instance method. Write some bytes to the scalar.
81 Seeking/telling and other attributes
83 autoflush
84 Instance method. No-op, provided for OO compatibility.
85 binmode
87 Instance method. No-op, provided for OO compatibility.
88 clearerr
90 Instance method. Clear the error and EOF flags. A no-op.
91 eof Instance method. Are we at end of file?
93 seek OFFSET, WHENCE
95 Instance method. Seek to a given position in the stream.
96 sysseek OFFSET, WHENCE
98 Instance method. Identical to "seek OFFSET, WHENCE", q.v.
99 tell
101 Instance method. Return the current position in the stream, as a
102 numeric offset.
103 use_RS [YESNO]
105 Instance method. Deprecated and ignored. Obey the current setting
106 of $/, like IO::Handle does? Default is false in 1.x, but cold-
107 welded true in 2.x and later.
108 setpos POS
110 Instance method. Set the current position, using the opaque value
111 returned by "getpos()".
112 getpos
114 Instance method. Return the current position in the string, as an
115 opaque object.
116 sref
118 Instance method. Return a reference to the underlying scalar.
119
121 Perl's TIEHANDLE spec was incomplete prior to 5.005_57; it was missing
122 support for "seek()", "tell()", and "eof()". Attempting to use these
123 functions with an IO::Scalar will not work prior to 5.005_57.
124 IO::Scalar will not have the relevant methods invoked; and even worse,
125 this kind of bug can lie dormant for a while. If you turn warnings on
126 (via $^W or "perl -w"), and you see something like this...
127 attempt to seek on unopened filehandle
129 ...then you are probably trying to use one of these functions on an
131 IO::Scalar with an old Perl. The remedy is to simply use the OO
132 version; e.g.:
133 $SH->seek(0,0); ### GOOD: will work on any 5.005
135 seek($SH,0,0); ### WARNING: will only work on 5.005_57 and beyond
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138 $Id: Scalar.pm,v 1.6 2005/02/10 21:21:53 dfs Exp $
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141 Primary Maintainer
142 David F. Skoll (dfs@roaringpenguin.com).
143 Principal author
145 Eryq (eryq@zeegee.com). President, ZeeGee Software Inc
146 (http://www.zeegee.com).
147 Other contributors
149 The full set of contributors always includes the folks mentioned in
150 "CHANGE LOG" in IO::Stringy. But just the same, special thanks to the
151 following individuals for their invaluable contributions (if I've
152 forgotten or misspelled your name, please email me!):
153 Andy Glew, for contributing "getc()".
155 Brandon Browning, for suggesting "opened()".
157 David Richter, for finding and fixing the bug in "PRINTF()".
159 Eric L. Brine, for his offset-using read() and write() implementations.
161 Richard Jones, for his patches to massively improve the performance of
163 "getline()" and add "sysread" and "syswrite".
164 B. K. Oxley (binkley), for stringification and inheritance
166 improvements, and sundry good ideas.
167 Doug Wilson, for the IO::Handle inheritance and automatic tie-ing.
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171 IO::String, which is quite similar but which was designed more-recently
172 and with an IO::Handle-like interface in mind, so you could mix OO- and
173 native-filehandle usage without using tied().
174 Note: as of version 2.x, these classes all work like their IO::Handle
176 counterparts, so we have comparable functionality to IO::String.
177perl v5.28.0 2018-08-13 Test::Builder::IO::Scalar(3)