Perl 5 version 22.4 documentation

IO::File

NAME

IO::File - supply object methods for filehandles

SYNOPSIS

  1.     use IO::File;
  3.     $fh = IO::File->new();
  4.     if ($fh->open("< file")) {
  5.         print <$fh>;
  6.         $fh->close;
  7.     }
  9.     $fh = IO::File->new("> file");
  10.     if (defined $fh) {
  11.         print $fh "bar\n";
  12.         $fh->close;
  13.     }
  15.     $fh = IO::File->new("file", "r");
  16.     if (defined $fh) {
  17.         print <$fh>;
  18.         undef $fh;       # automatically closes the file
  19.     }
  21.     $fh = IO::File->new("file", O_WRONLY|O_APPEND);
  22.     if (defined $fh) {
  23.         print $fh "corge\n";
  25.         $pos = $fh->getpos;
  26.         $fh->setpos($pos);
  28.         undef $fh;       # automatically closes the file
  29.     }
  31.     autoflush STDOUT 1;

DESCRIPTION

IO::File inherits from IO::Handle and IO::Seekable . It extends these classes with methods that are specific to file handles.

CONSTRUCTOR

  • 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.

METHODS

  • 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.

NOTE

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.

SEE ALSO

perlfunc, I/O Operators in perlop, IO::Handle, IO::Seekable, IO::Dir

HISTORY

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