FileHandle(3perl)					 Perl Programmers Reference Guide					 FileHandle(3perl)

NAME

       FileHandle - supply object methods for filehandles

SYNOPSIS

	   use FileHandle;

	   $fh = FileHandle->new;
	   if ($fh->open("< file")) {
	       print <$fh>;
	       $fh->close;
	   }

	   $fh = FileHandle->new("> FOO");
	   if (defined $fh) {
	       print $fh "bar
";
	       $fh->close;
	   }

	   $fh = FileHandle->new("file", "r");
	   if (defined $fh) {
	       print <$fh>;
	       undef $fh;	# automatically closes the file
	   }

	   $fh = FileHandle->new("file", O_WRONLY|O_APPEND);
	   if (defined $fh) {
	       print $fh "corge
";
	       undef $fh;	# automatically closes the file
	   }

	   $pos = $fh->getpos;
	   $fh->setpos($pos);

	   $fh->setvbuf($buffer_var, _IOLBF, 1024);

	   ($readfh, $writefh) = FileHandle::pipe;

	   autoflush STDOUT 1;

DESCRIPTION

       NOTE: This class is now a front-end to the IO::* classes.

       "FileHandle::new" creates a "FileHandle", which is a reference to a newly created symbol (see the "Symbol" package).  If it receives any
       parameters, they are passed to "FileHandle::open"; if the open fails, the "FileHandle" object is destroyed.  Otherwise, it is returned to
       the caller.

       "FileHandle::new_from_fd" creates a "FileHandle" like "new" does.  It requires two parameters, which are passed to "FileHandle::fdopen"; if
       the fdopen fails, the "FileHandle" object is destroyed.	Otherwise, it is returned to the caller.

       "FileHandle::open" accepts one parameter or two.  With one parameter, it is just a front end for the built-in "open" function.  With two
       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 "FileHandle::open" receives a Perl mode string (">", "+<", etc.)  or a POSIX fopen() mode string ("w", "r+", etc.), it uses the basic
       Perl "open" operator.

       If "FileHandle::open" is given a numeric mode, it passes that mode and the optional permissions value to the Perl "sysopen" operator.  For
       convenience, "FileHandle::import" tries to import the O_XXX constants from the Fcntl module.  If dynamic loading is not available, this may
       fail, but the rest of FileHandle will still work.

       "FileHandle::fdopen" is like "open" except that its first parameter is not a filename but rather a file handle name, a FileHandle object,
       or a file descriptor number.

       If the C functions fgetpos() and fsetpos() are available, then "FileHandle::getpos" returns an opaque value that represents the current
       position of the FileHandle, and "FileHandle::setpos" uses that value to return to a previously visited position.

       If the C function setvbuf() is available, then "FileHandle::setvbuf" sets the buffering policy for the FileHandle.  The calling sequence
       for the Perl function is the same as its C counterpart, including the macros "_IOFBF", "_IOLBF", and "_IONBF", except that the buffer
       parameter specifies a scalar variable to use as a buffer.  WARNING: A variable used as a buffer by "FileHandle::setvbuf" must not be
       modified in any way until the FileHandle is closed or until "FileHandle::setvbuf" is called again, or memory corruption may result!

       See perlfunc for complete descriptions of each of the following supported "FileHandle" methods, which are just front ends for the
       corresponding built-in functions:

	   close
	   fileno
	   getc
	   gets
	   eof
	   clearerr
	   seek
	   tell

       See perlvar for complete descriptions of each of the following supported "FileHandle" methods:

	   autoflush
	   output_field_separator
	   output_record_separator
	   input_record_separator
	   input_line_number
	   format_page_number
	   format_lines_per_page
	   format_lines_left
	   format_name
	   format_top_name
	   format_line_break_characters
	   format_formfeed

       Furthermore, for doing normal I/O you might need these:

       $fh->print
	   See "print" in perlfunc.

       $fh->printf
	   See "printf" in perlfunc.

       $fh->getline
	   This works like <$fh> described in "I/O Operators" in perlop except that it's more readable and can be safely called in a list context
	   but still returns just one line.

       $fh->getlines
	   This works like <$fh> when called in a list context to read all the remaining lines in a file, except that it's more readable.  It will
	   also croak() if accidentally called in a scalar context.

       There are many other functions available since FileHandle is descended from IO::File, IO::Seekable, and IO::Handle.  Please see those
       respective pages for documentation on more functions.

SEE ALSO

       The IO extension, perlfunc, "I/O Operators" in perlop.

perl v5.14.2							    2010-12-30							 FileHandle(3perl)