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IO::File(3) |
Perl Programmers Reference Guide |
IO::File(3) |
IO::File - supply object methods for filehandles
use IO::File;
$fh = IO::File->new();
if ($fh->open("< file")) {
print <$fh>;
$fh->close;
}
$fh = IO::File->new("> file");
if (defined $fh) {
print $fh "bar\n";
$fh->close;
}
$fh = IO::File->new("file", "r");
if (defined $fh) {
print <$fh>;
undef $fh; # automatically closes the file
}
$fh = IO::File->new("file", O_WRONLY|O_APPEND);
if (defined $fh) {
print $fh "corge\n";
$pos = $fh->getpos;
$fh->setpos($pos);
undef $fh; # automatically closes the file
}
autoflush STDOUT 1;
"IO::File" inherits from
"IO::Handle" and
"IO::Seekable". It extends these classes
with methods that are specific to file handles.
- new ( FILENAME [,MODE [,PERMS]] )
- Creates an "IO::File". If it receives
any parameters, they are passed to the method
"open"; if the open fails, the object is
destroyed. Otherwise, it is returned to the caller.
- new_tmpfile
- Creates an "IO::File" opened for
read/write on a newly created temporary file. On systems where this is
possible, the temporary file is anonymous (i.e. it is unlinked after
creation, but held open). If the temporary file cannot be created or
opened, the "IO::File" object is
destroyed. Otherwise, it is returned to the caller.
- open( FILENAME [,MODE [,PERMS]] )
- open( FILENAME, IOLAYERS )
- "open" accepts one, two or three
parameters. With one parameter, it is just a front end for the built-in
"open" function. With two or three
parameters, the first parameter is a filename that may include whitespace
or other special characters, and the second parameter is the open mode,
optionally followed by a file permission value.
If "IO::File::open" receives
a Perl mode string (">", "+<", etc.) or an
ANSI C fopen() mode string ("w", "r+", etc.),
it uses the basic Perl "open" operator
(but protects any special characters).
If "IO::File::open" is given
a numeric mode, it passes that mode and the optional permissions value
to the Perl "sysopen" operator. The
permissions default to 0666.
If "IO::File::open" is given
a mode that includes the ":"
character, it passes all the three arguments to the three-argument
"open" operator.
For convenience, "IO::File"
exports the O_XXX constants from the Fcntl module, if this module is
available.
- binmode( [LAYER] )
- "binmode" sets
"binmode" on the underlying
"IO" object, as documented in
"perldoc -f binmode".
"binmode" accepts one
optional parameter, which is the layer to be passed on to the
"binmode" call.
Some operating systems may perform
"IO::File::new()" or
"IO::File::open()" on a directory without
errors. This behavior is not portable and not suggested for use. Using
"opendir()" and
"readdir()" or
"IO::Dir" are suggested instead.
perlfunc, "I/O Operators" in perlop, IO::Handle, IO::Seekable, IO::Dir
Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>.
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