file::randomaccess(3) [suse man page]

File::RandomAccess(3)					User Contributed Perl Documentation				     File::RandomAccess(3)

NAME

       File::RandomAccess - Random access reads of sequential file or scalar

SYNOPSIS

	   use File::RandomAccess;

	   $raf = new File::RandomAccess(*FILE, $disableSeekTest);

	   $raf = new File::RandomAccess($data);

	   $err = $raf->Seek($pos);
	   $num = $raf->Read($buff, $bytes);

DESCRIPTION

       Allows random access to sequential file by buffering the file if necessary.  Also allows access to data in memory to be accessed as if it
       were a file.

METHODS

       new Creates a new RandomAccess object given a file reference or reference to data in memory.

	       # Read from open file or pipe
	       $raf = new File::RandomAccess(*FILE);

	       # Read from data in memory
	       $raf = new File::RandomAccess($data);

	   Inputs:
	       0) Reference to RandomAccess object.

	       1) File reference or scalar reference.

	       2) flag set if file is already random access (disables automatic SeekTest).

	   Returns:
	       Reference to RandomAccess object.

       SeekTest
	   Performs test seek() on file to determine if buffering is necessary.  If the seek() fails, then the file is buffered to allow random
	   access.  SeekTest() is automatically called from new unless specified.

	       $result = $raf->SeekTest();

	   Inputs:
	       0) Reference to RandomAccess object.

	   Returns:
	       1 if seek test passed (ie. no buffering required).

	   Notes:
	       Must be called before any other i/o.

       Tell
	   Get current position in file

	       $pos = $raf->Tell();

	   Inputs:
	       0) Reference to RandomAccess object.

	   Returns:
	       Current position in file

       Seek
	   Seek to specified position in file.	When buffered, this doesn't quite behave like seek() since it returns success even if you seek
	   outside the limits of the file.

	       $success = $raf->Seek($pos, 0);

	   Inputs:
	       0) Reference to RandomAccess object.

	       1) Position.

	       2) Whence (0=from start, 1=from cur pos, 2=from end).

	   Returns:
	       1 on success, 0 otherwise

       Read
	   Read data from the file.

	       $num = $raf->Read($buff, 1024);

	   Inputs:
	       0) Reference to RandomAccess object.

	       1) Buffer.

	       2) Number of bytes to read.

	   Returns:
	       Number of bytes actually read.

       ReadLine
	   Read a line from file (end of line is $/).

	   Inputs:
	       0) Reference to RandomAccess object.

	       1) Buffer.

	   Returns:
	       Number of bytes read.

       Slurp
	   Read whole file into buffer, without changing read pointer.

	   Inputs:
	       0) Reference to RandomAccess object.

	   Returns:
	       Nothing.

       BinMode
	   Set binary mode for file.

	   Inputs:
	       0) Reference to RandomAccess object.

	   Returns:
	       Nothing.

       Close
	   Close the file and free the buffer.

	   Inputs:
	       0) Reference to RandomAccess object.

	   Returns:
	       Nothing.

AUTHOR

       Copyright 2003-2010 Phil Harvey (phil at owl.phy.queensu.ca)

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

       Image::ExifTool(3pm)

perl v5.12.1							    2010-01-04						     File::RandomAccess(3)

Check Out this Related Man Page

IO::Seekable(3pm)					 Perl Programmers Reference Guide					 IO::Seekable(3pm)

NAME

       IO::Seekable - supply seek based methods for I/O objects

SYNOPSIS

	   use IO::Seekable;
	   package IO::Something;
	   @ISA = qw(IO::Seekable);

DESCRIPTION

       "IO::Seekable" does not have a constructor of its own as it is intended to be inherited by other "IO::Handle" based objects. It provides
       methods which allow seeking of the file descriptors.

       $io->getpos
	   Returns an opaque value that represents the current position of the IO::File, or "undef" if this is not possible (eg an unseekable
	   stream such as a terminal, pipe or socket). If the fgetpos() function is available in your C library it is used to implements getpos,
	   else perl emulates getpos using C's ftell() function.

       $io->setpos
	   Uses the value of a previous getpos call to return to a previously visited position. Returns "0 but true" on success, "undef" on
	   failure.

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

       $io->seek ( POS, WHENCE )
	   Seek the IO::File to position POS, relative to WHENCE:

	   WHENCE=0 (SEEK_SET)
		   POS is absolute position. (Seek relative to the start of the file)

	   WHENCE=1 (SEEK_CUR)
		   POS is an offset from the current position. (Seek relative to current)

	   WHENCE=2 (SEEK_END)
		   POS is an offset from the end of the file. (Seek relative to end)

	   The SEEK_* constants can be imported from the "Fcntl" module if you don't wish to use the numbers 0 1 or 2 in your code.

	   Returns 1 upon success, 0 otherwise.

       $io->sysseek( POS, WHENCE )
	   Similar to $io->seek, but sets the IO::File's position using the system call lseek(2) directly, so will confuse most perl IO operators
	   except sysread and syswrite (see perlfunc for full details)

	   Returns the new position, or "undef" on failure.  A position of zero is returned as the string "0 but true"

       $io->tell
	   Returns the IO::File's current position, or -1 on error.

SEE ALSO

       perlfunc, "I/O Operators" in perlop, IO::Handle IO::File

HISTORY

       Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>

perl v5.16.2							    2012-08-26							 IO::Seekable(3pm)

Linux and UNIX Man Pages

file::randomaccess(3) [suse man page]

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