1IO::File(3pm) Perl Programmers Reference Guide IO::File(3pm)
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6 IO::File - supply object methods for filehandles
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9 use IO::File;
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11 $fh = IO::File->new();
12 if ($fh->open("< file")) {
13 print <$fh>;
14 $fh->close;
15 }
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17 $fh = IO::File->new("> file");
18 if (defined $fh) {
19 print $fh "bar\n";
20 $fh->close;
21 }
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23 $fh = IO::File->new("file", "r");
24 if (defined $fh) {
25 print <$fh>;
26 undef $fh; # automatically closes the file
27 }
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29 $fh = IO::File->new("file", O_WRONLY|O_APPEND);
30 if (defined $fh) {
31 print $fh "corge\n";
32
33 $pos = $fh->getpos;
34 $fh->setpos($pos);
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36 undef $fh; # automatically closes the file
37 }
38
39 autoflush STDOUT 1;
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42 "IO::File" inherits from "IO::Handle" and "IO::Seekable". It extends
43 these classes with methods that are specific to file handles.
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46 new ( FILENAME [,MODE [,PERMS]] )
47 Creates an "IO::File". If it receives any parameters, they are
48 passed to the method "open"; if the open fails, the object is
49 destroyed. Otherwise, it is returned to the caller.
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51 new_tmpfile
52 Creates an "IO::File" opened for read/write on a newly created
53 temporary file. On systems where this is possible, the temporary
54 file is anonymous (i.e. it is unlinked after creation, but held
55 open). If the temporary file cannot be created or opened, the
56 "IO::File" object is destroyed. Otherwise, it is returned to the
57 caller.
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60 open( FILENAME [,MODE [,PERMS]] )
61 open( FILENAME, IOLAYERS )
62 "open" accepts one, two or three parameters. With one parameter,
63 it is just a front end for the built-in "open" function. With two
64 or three parameters, the first parameter is a filename that may
65 include whitespace or other special characters, and the second
66 parameter is the open mode, optionally followed by a file
67 permission value.
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69 If "IO::File::open" receives a Perl mode string (">", "+<", etc.)
70 or an ANSI C fopen() mode string ("w", "r+", etc.), it uses the
71 basic Perl "open" operator (but protects any special characters).
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73 If "IO::File::open" is given a numeric mode, it passes that mode
74 and the optional permissions value to the Perl "sysopen" operator.
75 The permissions default to 0666.
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77 If "IO::File::open" is given a mode that includes the ":"
78 character, it passes all the three arguments to the three-argument
79 "open" operator.
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81 For convenience, "IO::File" exports the O_XXX constants from the
82 Fcntl module, if this module is available.
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84 binmode( [LAYER] )
85 "binmode" sets "binmode" on the underlying "IO" object, as
86 documented in "perldoc -f binmode".
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88 "binmode" accepts one optional parameter, which is the layer to be
89 passed on to the "binmode" call.
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92 Some operating systems may perform "IO::File::new()" or
93 "IO::File::open()" on a directory without errors. This behavior is not
94 portable and not suggested for use. Using "opendir()" and "readdir()"
95 or "IO::Dir" are suggested instead.
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98 perlfunc, "I/O Operators" in perlop, IO::Handle, IO::Seekable, IO::Dir
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101 Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>.
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105perl v5.26.3 2018-03-01 IO::File(3pm)