1MemHandle(3) User Contributed Perl Documentation MemHandle(3)
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6 MemHandle - supply memory-based FILEHANDLE methods
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8 DEPRECATED - Please use IO::Scalar from CPAN package IO::stringy
9 instead!
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12 use MemHandle;
13 use IO::Seekable;
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15 my $mh = new MemHandle;
16 print $mh "foo\n";
17 $mh->print( "bar\n" );
18 printf $mh "This is a number: %d\n", 10;
19 $mh->printf( "a string: \"%s\"\n", "all strings come to those who wait" );
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21 my $len = $mh->tell(); # Use $mh->tell();
22 # tell( $mh ) will NOT work!
23 $mh->seek(0, SEEK_SET); # Use $mh->seek($where, $whence)
24 # seek($mh, $where, $whence)
25 # will NOT work!
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27 my $memory = $mh->mem();
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29 Here's the real meat:
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31 my $mh = new MemHandle;
32 my $old = select( $mh );
33 .
34 .
35 .
36 print "foo bar\n";
37 print "baz\n";
38 &MyPrintSub();
39 select( $old );
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41 print "here it all is: ", $mh->mem(), "\n";
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44 Generates inherits from "IO::Handle" and "IO::Seekable". It provides an
45 interface to the file routines which uses memory instead. See perldoc
46 IO::Handle, and perldoc IO::Seekable as well as perlfunc for more
47 detailed descriptions of the provided built-in functions:
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49 print
50 printf
51 readline
52 sysread
53 syswrite
54 getc
55 gets
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57 The following functions are provided, but tie doesn't allow them to be
58 tied to the built in functions. They should be used by calling the
59 appropriate method on the MemHandle object.
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61 seek
62 tell
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64 call them like this:
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66 my $mh = new MemHandle();
67 .
68 .
69 .
70 my $pos = $mh->tell();
71 $mh->seek( 0, SEEK_SET );
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74 new( [mem] )
75 Creates a "MemHandle", which is a reference to a newly created
76 symbol (see the "Symbol" package). It then ties the FILEHANDLE to
77 "MemHandle::Tie" (see "Tying FileHandles" in perltie). Tied
78 methods in "MemHandle::Tie" translate file operations into
79 reads/writes into a string, which can be accessed by calling
80 "MemHandle::mem".
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83 seek( POS, WHENCE )
84 Sets the read/write position to WHENCE + POS. WHENCE is one of the
85 constants which are available from IO::Seekable or POSIX:
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87 SEEK_SET # absolute position from the beginning.
88 SEEK_CUR # offset from the current location.
89 SEEK_END # from the end (POS can be negative).
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91 tell()
92 Returns the current position of the mem-file, similar to the way
93 tell would. (See perlfunc).
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95 mem( [mem] )
96 gets or sets the memory. If called with a parameter, it copies it
97 to the memory and sets the position to be immediately after (so if
98 you write more to it, you append the string). Returns the current
99 value of memory.
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102 I don't have much time to contribute to this. If you'd like to
103 contribute, please fork https://github.com/scr/cpan and send me a pull
104 request.
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107 "Sheridan C. Rawlins" <scr14@cornell.edu>
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110 perl. perlfunc. "Tying FileHandles" in perltie. perldoc IO::Handle.
111 perldoc IO::Seekable. perldoc Symbol.
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115perl v5.30.1 2020-01-30 MemHandle(3)