1IO::ScalarArray(3)    User Contributed Perl Documentation   IO::ScalarArray(3)
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NAME

6       IO::ScalarArray - IO:: interface for reading/writing an array of
7       scalars
8

SYNOPSIS

10       Perform I/O on strings, using the basic OO interface...
11
12           use IO::ScalarArray;
13           @data = ("My mes", "sage:\n");
14
15           ### Open a handle on an array, and append to it:
16           $AH = new IO::ScalarArray \@data;
17           $AH->print("Hello");
18           $AH->print(", world!\nBye now!\n");
19           print "The array is now: ", @data, "\n";
20
21           ### Open a handle on an array, read it line-by-line, then close it:
22           $AH = new IO::ScalarArray \@data;
23           while (defined($_ = $AH->getline)) {
24               print "Got line: $_";
25           }
26           $AH->close;
27
28           ### Open a handle on an array, and slurp in all the lines:
29           $AH = new IO::ScalarArray \@data;
30           print "All lines:\n", $AH->getlines;
31
32           ### Get the current position (either of two ways):
33           $pos = $AH->getpos;
34           $offset = $AH->tell;
35
36           ### Set the current position (either of two ways):
37           $AH->setpos($pos);
38           $AH->seek($offset, 0);
39
40           ### Open an anonymous temporary array:
41           $AH = new IO::ScalarArray;
42           $AH->print("Hi there!");
43           print "I printed: ", @{$AH->aref}, "\n";      ### get at value
44
45       Don't like OO for your I/O?  No problem.  Thanks to the magic of an
46       invisible tie(), the following now works out of the box, just as it
47       does with IO::Handle:
48
49           use IO::ScalarArray;
50           @data = ("My mes", "sage:\n");
51
52           ### Open a handle on an array, and append to it:
53           $AH = new IO::ScalarArray \@data;
54           print $AH "Hello";
55           print $AH ", world!\nBye now!\n";
56           print "The array is now: ", @data, "\n";
57
58           ### Open a handle on a string, read it line-by-line, then close it:
59           $AH = new IO::ScalarArray \@data;
60           while (<$AH>) {
61               print "Got line: $_";
62           }
63           close $AH;
64
65           ### Open a handle on a string, and slurp in all the lines:
66           $AH = new IO::ScalarArray \@data;
67           print "All lines:\n", <$AH>;
68
69           ### Get the current position (WARNING: requires 5.6):
70           $offset = tell $AH;
71
72           ### Set the current position (WARNING: requires 5.6):
73           seek $AH, $offset, 0;
74
75           ### Open an anonymous temporary scalar:
76           $AH = new IO::ScalarArray;
77           print $AH "Hi there!";
78           print "I printed: ", @{$AH->aref}, "\n";      ### get at value
79
80       And for you folks with 1.x code out there: the old tie() style still
81       works, though this is unnecessary and deprecated:
82
83           use IO::ScalarArray;
84
85           ### Writing to a scalar...
86           my @a;
87           tie *OUT, 'IO::ScalarArray', \@a;
88           print OUT "line 1\nline 2\n", "line 3\n";
89           print "Array is now: ", @a, "\n"
90
91           ### Reading and writing an anonymous scalar...
92           tie *OUT, 'IO::ScalarArray';
93           print OUT "line 1\nline 2\n", "line 3\n";
94           tied(OUT)->seek(0,0);
95           while (<OUT>) {
96               print "Got line: ", $_;
97           }
98

DESCRIPTION

100       This class is part of the IO::Stringy distribution; see IO::Stringy for
101       change log and general information.
102
103       The IO::ScalarArray class implements objects which behave just like
104       IO::Handle (or FileHandle) objects, except that you may use them to
105       write to (or read from) arrays of scalars.  Logically, an array of
106       scalars defines an in-core "file" whose contents are the concatenation
107       of the scalars in the array.  The handles created by this class are
108       automatically "tiehandle"d (though please see "WARNINGS" for
109       information relevant to your Perl version).
110
111       For writing large amounts of data with individual print() statements,
112       this class is likely to be more efficient than IO::Scalar.
113
114       Basically, this:
115
116           my @a;
117           $AH = new IO::ScalarArray \@a;
118           $AH->print("Hel", "lo, ");         ### OO style
119           $AH->print("world!\n");            ### ditto
120
121       Or this:
122
123           my @a;
124           $AH = new IO::ScalarArray \@a;
125           print $AH "Hel", "lo, ";           ### non-OO style
126           print $AH "world!\n";              ### ditto
127
128       Causes @a to be set to the following array of 3 strings:
129
130           ( "Hel" ,
131             "lo, " ,
132             "world!\n" )
133
134       See IO::Scalar and compare with this class.
135

PUBLIC INTERFACE

137   Construction
138       new [ARGS...]
139           Class method.  Return a new, unattached array handle.  If any
140           arguments are given, they're sent to open().
141
142       open [ARRAYREF]
143           Instance method.  Open the array handle on a new array, pointed to
144           by ARRAYREF.  If no ARRAYREF is given, a "private" array is created
145           to hold the file data.
146
147           Returns the self object on success, undefined on error.
148
149       opened
150           Instance method.  Is the array handle opened on something?
151
152       close
153           Instance method.  Disassociate the array handle from its underlying
154           array.  Done automatically on destroy.
155
156   Input and output
157       flush
158           Instance method.  No-op, provided for OO compatibility.
159
160       fileno
161           Instance method.  No-op, returns undef
162
163       getc
164           Instance method.  Return the next character, or undef if none
165           remain.  This does a read(1), which is somewhat costly.
166
167       getline
168           Instance method.  Return the next line, or undef on end of data.
169           Can safely be called in an array context.  Currently, lines are
170           delimited by "\n".
171
172       getlines
173           Instance method.  Get all remaining lines.  It will croak() if
174           accidentally called in a scalar context.
175
176       print ARGS...
177           Instance method.  Print ARGS to the underlying array.
178
179           Currently, this always causes a "seek to the end of the array" and
180           generates a new array entry.  This may change in the future.
181
182       read BUF, NBYTES, [OFFSET];
183           Instance method.  Read some bytes from the array.  Returns the
184           number of bytes actually read, 0 on end-of-file, undef on error.
185
186       write BUF, NBYTES, [OFFSET];
187           Instance method.  Write some bytes into the array.
188
189   Seeking/telling and other attributes
190       autoflush
191           Instance method.  No-op, provided for OO compatibility.
192
193       binmode
194           Instance method.  No-op, provided for OO compatibility.
195
196       clearerr
197           Instance method.  Clear the error and EOF flags.  A no-op.
198
199       eof Instance method.  Are we at end of file?
200
201       seek POS,WHENCE
202           Instance method.  Seek to a given position in the stream.  Only a
203           WHENCE of 0 (SEEK_SET) is supported.
204
205       tell
206           Instance method.  Return the current position in the stream, as a
207           numeric offset.
208
209       setpos POS
210           Instance method.  Seek to a given position in the array, using the
211           opaque getpos() value.  Don't expect this to be a number.
212
213       getpos
214           Instance method.  Return the current position in the array, as an
215           opaque value.  Don't expect this to be a number.
216
217       aref
218           Instance method.  Return a reference to the underlying array.
219

AUTHOR

221       Eryq (eryq@zeegee.com).  President, ZeeGee Software Inc
222       (http://www.zeegee.com).
223

CONTRIBUTORS

225       Dianne Skoll (dfs@roaringpenguin.com).
226

228       Copyright (c) 1997 Erik (Eryq) Dorfman, ZeeGee Software, Inc. All
229       rights reserved.
230
231       This program is free software; you can redistribute it and/or modify it
232       under the same terms as Perl itself.
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236perl v5.34.0                      2022-01-21                IO::ScalarArray(3)
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