NAME

    IO::All - IO::All to Larry Wall!

VERSION

    This document describes IO::All version 0.87.

SYNOPSIS

    First, some safe examples:

        use IO::All;

        # Some of the many ways to read a whole file into a scalar

        $contents = io->file('file.txt')->slurp;    # Read an entire file

        @files    = io->dir('lib')->all;            # Get a list of files

        $tail     = io->pipe('-| tail app.log');    # Open a pipe to a command

        $line     = $tail->getline;                 # Read from the pipe

    That said, there are a lot more things that are very convenient and

    will help you write code very quickly, though they should be used

    judiciously:

        use IO::All;                                # Let the madness begin...

        # Some of the many ways to read a whole file into a scalar

        io('file.txt') > $contents;                 # Overloaded "arrow"

        $contents < io 'file.txt';                  # Flipped but same operation

        $io = io 'file.txt';                        # Create a new IO::All object

        $contents = $$io;                           # Overloaded scalar dereference

        $contents = $io->all;                       # A method to read everything

        $contents = $io->slurp;                     # Another method for that

        $contents = join '', $io->getlines;         # Join the separate lines

        $contents = join '', map "$_\n", @$io;      # Same. Overloaded array deref

        $io->tie;                                   # Tie the object as a handle

        $contents = join '', <$io>;                 # And use it in builtins

        # and the list goes on ...

        # Other file operations:

        @lines = io('file.txt')->slurp;             # List context slurp

        $content > io('file.txt');                  # Print to a file

        io('file.txt')->print($content, $more);     # (ditto)

        $content >> io('file.txt');                 # Append to a file

        io('file.txt')->append($content);           # (ditto)

        $content << $io;                            # Append to a string

        io('copy.txt') < io('file.txt');            $ Copy a file

        io('file.txt') > io('copy.txt');            # Invokes File::Copy

        io('more.txt') >> io('all.txt');            # Add on to a file

        io('dir/') < io('file.txt');                $ Copy a file to a directory

        io('file.txt') > io('dir/');                # Invokes File::Copy

        io('more.txt') >> io('dir/');               # Add on to a file in the dir

        # UTF-8 Support

        $contents = io('file.txt')->utf8->all;      # Turn on utf8

        use IO::All -utf8;                          # Turn on utf8 for all io

        $contents = io('file.txt')->all;            #   by default in this package.

        # General Encoding Support

        $contents = io('file.txt')->encoding('big5')->all;

        use IO::All -encoding => 'big5';            # Turn on big5 for all io

        $contents = io('file.txt')->all;            #   by default in this package.

        # Print the path name of a file:

        print $io->name;                            # The direct method

        print "$io";                                # Object stringifies to name

        print $io;                                  # Quotes not needed here

        print $io->filename;                        # The file portion only

        $io->os('win32');                           # change the object to be a

                                                    # win32 path

        print $io->ext;                             # The file extension only

        print $io->mimetype;                        # The mimetype, requires a

                                                    #  working File::MimeType

        # Read all the files/directories in a directory:

        $io = io('my/directory/');                  # Create new directory object

        @contents = $io->all;                       # Get all contents of dir

        @contents = @$io;                           # Directory as an array

        @contents = values %$io;                    # Directory as a hash

        push @contents, $subdir                     # One at a time

          while $subdir = $io->next;

        # Print the name and file type for all the contents above:

        print "$_ is a " . $_->type . "\n"          # Each element of @contents

          for @contents;                            # is an IO::All object!!

        # Print first line of each file:

        print $_->getline                           # getline gets one line

          for io('dir')->all_files;                 # Files only

        # Print names of all files/dirs three directories deep:

        print "$_\n" for $io->all(3);               # Pass in the depth. Default=1

        # Print names of all files/dirs recursively:

        print "$_\n" for $io->all(0);               # Zero means all the way down

        print "$_\n" for $io->All;                  # Capitalized shortcut

        print "$_\n" for $io->deep->all;            # Another way

        # There are some special file names:

        print io('-');                              # Print STDIN to STDOUT

        io('-') > io('-');                          # Do it again

        io('-') < io('-');                          # Same. Context sensitive.

        "Bad puppy" > io('=');                      # Message to STDERR

        $string_file = io('$');                     # Create string based filehandle

        $temp_file = io('?');                       # Create a temporary file

        # Socket operations:

        $server = io('localhost:5555')->fork;       # Create a daemon socket

        $connection = $server->accept;              # Get a connection socket

        $input < $connection;                       # Get some data from it

        "Thank you!" > $connection;                 # Thank the caller

        $connection->close;                         # Hang up

        io(':6666')->accept->slurp > io->devnull;   # Take a complaint and file it

        # DBM database operations:

        $dbm = io 'my/database';                    # Create a database object

        print $dbm->{grocery_list};                 # Hash context makes it a DBM

        $dbm->{todo} = $new_list;                   # Write to database

        $dbm->dbm('GDBM_file');                     # Demand specific DBM

        io('mydb')->mldbm->{env} = \%ENV;           # MLDBM support

        # Tie::File support:

        $io = io 'file.txt';

        $io->[42] = 'Line Forty Three';             # Change a line

        print $io->[@$io / 2];                      # Print middle line

        @$io = reverse @$io;                        # Reverse lines in a file

        # Stat functions:

        printf "%s %s %s\n",                        # Print name, uid and size of

          $_->name, $_->uid, $_->size               # contents of current directory

            for io('.')->all;

        print "$_\n" for sort                       # Use mtime method to sort all

          {$b->mtime <=> $a->mtime}                 # files under current directory

            io('.')->All_Files;                     # by recent modification time.

        # File::Spec support:

        $contents < io->catfile(qw(dir file.txt));  # Portable IO operation

        # Miscellaneous:

        @lines = io('file.txt')->chomp->slurp;      # Chomp as you slurp

        @chunks =

          io('file.txt')->separator('xxx')->slurp;  # Use alternnate record sep

        $binary = io('file.bin')->binary->all;      # Read a binary file

        io('a-symlink')->readlink->slurp;           # Readlink returns an object

        print io('foo')->absolute->pathname;        # Print absolute path of foo

        # IO::All External Plugin Methods

        io("myfile") > io->("ftp://store.org");     # Upload a file using ftp

        $html < io->http("www.google.com");         # Grab a web page

        io('mailto:worst@enemy.net')->print($spam); # Email a "friend"

        # This is just the beginning, read on...

DESCRIPTION

    IO::All combines all of the best Perl IO modules into a single nifty

    object oriented interface to greatly simplify your everyday Perl IO

    idioms. It exports a single function called io, which returns a new

    IO::All object. And that object can do it all!

    The IO::All object is a proxy for IO::File, IO::Dir, IO::Socket,

    Tie::File, File::Spec, File::Path, File::MimeInfo and

    File::ReadBackwards; as well as all the DBM and MLDBM modules. You can

    use most of the methods found in these classes and in IO::Handle (which

    they inherit from). IO::All adds dozens of other helpful idiomatic

    methods including file stat and manipulation functions.

    IO::All is pluggable, and modules like IO::All::LWP and IO::All::Mailto

    add even more functionality. Optionally, every IO::All object can be

    tied to itself. This means that you can use most perl IO builtins on

    it: readline, <>, getc, print, printf, syswrite, sysread, close.

    The distinguishing magic of IO::All is that it will automatically open

    (and close) files, directories, sockets and other IO things for you.

    You never need to specify the mode (<, >>, etc), since it is determined

    by the usage context. That means you can replace this:

        open STUFF, '<', './mystuff'

          or die "Can't open './mystuff' for input:\n$!";

        local $/;

        my $stuff = <STUFF>;

        close STUFF;

    with this:

        my $stuff < io './mystuff';

    And that is a good thing!

USAGE

    Normally just say:

        use IO::All;

    and IO::All will export a single function called io, which constructs

    all IO objects.

 Note on io

    The io function is a magic constructor. It is easy to use and will

    usually do the right thing, but can also blow up easily.

    It takes a single optional argument and determines what type of IO::All

    subclass object to return. With no arguments it returns an IO::All

    object, which has no I/O methods, but has methods to construct subclass

    objects like IO::All::File.

    In other words, these 2 statements are usually the same:

        $content = io('file.txt')->all;

        $content = io->file('file.txt')->all;

    Use the first form when you are demonstrating your Perl virtues of

    laziness and impatience, and use the second form when your job is on

    the line.

METHOD ROLE CALL

    Here is an alphabetical list of all the public methods that you can

    call on an IO::All object.

    "abs2rel", "absolute", "accept", "All", "all", "All_Dirs", "all_dirs",

    "All_Files", "all_files", "All_Links", "all_links", "append",

    "appendf", "appendln", "assert", "atime", "autoclose", "autoflush",

    "backwards", "bcc", "binary", "binmode", "blksize", "blocks",

    "block_size", "buffer", "canonpath", "case_tolerant", "catdir",

    "catfile", "catpath", "cc", "chdir", "chomp", "clear", "close",

    "confess", "content", "copy", "ctime", "curdir", "dbm", "deep",

    "device", "device_id", "devnull", "dir", "domain", "empty", "ext",

    "encoding", "eof", "errors", "file", "filename", "fileno", "filepath",

    "filter", "fork", "from", "ftp", "get", "getc", "getline", "getlines",

    "gid", "glob", "handle", "head", "http", "https", "inode", "io_handle",

    "is_absolute", "is_dir", "is_dbm", "is_executable", "is_file",

    "is_link", "is_mldbm", "is_open", "is_pipe", "is_readable",

    "is_socket", "is_stdio", "is_string", "is_temp", "is_writable", "join",

    "length", "link", "lock", "mailer", "mailto", "mimetype", "mkdir",

    "mkpath", "mldbm", "mode", "modes", "mtime", "name", "new", "next",

    "nlink", "open", "os" "password", "path", "pathname", "perms", "pipe",

    "port", "print", "printf", "println", "put", "rdonly", "rdwr", "read",

    "readdir", "readlink", "recv", "rel2abs", "relative", "rename",

    "request", "response", "rmdir", "rmtree", "rootdir", "scalar", "seek",

    "send", "separator", "shutdown", "size", "slurp", "socket", "sort",

    "splitdir", "splitpath", "stat", "stdio", "stderr", "stdin", "stdout",

    "string", "string_ref", "subject", "sysread", "syswrite", "tail",

    "tell", "temp", "tie", "tmpdir", "to", "touch", "truncate", "type",

    "user", "uid", "unlink", "unlock", "updir", "uri", "utf8", "utime" and

    "write".

    Each method is documented further below.

OPERATOR OVERLOADING

    IO::All objects overload a small set of Perl operators to great effect.

    The overloads are limited to <, <<, >, >>, dereferencing operations,

    and stringification.

    Even though relatively few operations are overloaded, there is actually

    a huge matrix of possibilities for magic. That's because the

    overloading is sensitive to the types, position and context of the

    arguments, and an IO::All object can be one of many types.

    The most important overload to become familiar with is stringification.

    IO::All objects stringify to their file or directory name. Here we

    print the contents of the current directory:

        perl -MIO::All -le 'print for io(".")->all'

    is the same as:

        perl -MIO::All -le 'print $_->name for io(".")->all'

    Stringification is important because it allows IO::All operations to

    return objects when they might otherwise return file names. Then the

    recipient can use the result either as an object or a string.

    > and < move data between objects in the direction pointed to by the

    operator.

        $content1 < io('file1');

        $content1 > io('file2');

        io('file2') > $content3;

        io('file3') < $content3;

        io('file3') > io('file4');

        io('file5') < io('file4');

    >> and << do the same thing except the recipient string or file is

    appended to.

    An IO::All file used as an array reference becomes tied using

    Tie::File:

        $file = io "file";

        # Print last line of file

        print $file->[-1];

        # Insert new line in middle of file

        $file->[$#$file / 2] = 'New line';

    An IO::All file used as a hash reference becomes tied to a DBM class:

        io('mydbm')->{ingy} = 'YAML';

    An IO::All directory used as an array reference, will expose each file

    or subdirectory as an element of the array.

        print "$_\n" for @{io 'dir'};

    IO::All directories used as hash references have file names as keys,

    and IO::All objects as values:

        print io('dir')->{'foo.txt'}->slurp;

    Files used as scalar references get slurped:

        print ${io('dir')->{'foo.txt'}};

    Not all combinations of operations and object types are supported. Some

    just haven't been added yet, and some just don't make sense. If you use

    an invalid combination, an error will be thrown.

COOKBOOK

    This section describes some various things that you can easily cook up

    with IO::All.

 File Locking

    IO::All makes it very easy to lock files. Just use the lock method.

    Here's a standalone program that demonstrates locking for both write

    and read:

        use IO::All;

        my $io1 = io('myfile')->lock;

        $io1->println('line 1');

        fork or do {

          my $io2 = io('myfile')->lock;

          print $io2->slurp;

          exit;

        };

        sleep 1;

        $io1->println('line 2');

        $io1->println('line 3');

        $io1->unlock;

    There are a lot of subtle things going on here. An exclusive lock is

    issued for $io1 on the first println. That's because the file isn't

    actually opened until the first IO operation.

    When the child process tries to read the file using $io2, there is a

    shared lock put on it. Since $io1 has the exclusive lock, the slurp

    blocks.

    The parent process sleeps just to make sure the child process gets a

    chance. The parent needs to call unlock or close to release the lock.

    If all goes well the child will print 3 lines.

 In-place Editing

    Because an IO::All object can be used as an array reference, operations

    on arrays are supported transparently (using Tie::File) so a file can

    be modified in the same way you would modify an array.

        > cat > x.txt

        The sexy saxophone,

        got the axe.

        ^d

        > perl -MIO::All -e 'map { s/x/X/g; $_ } @{ io(shift) }' x.txt

        > cat x.txt

        The seXy saXophone,

        got the aXe.

     This one liner uses shift() to grab the file from STDIN and create an io

     object that is dereferenced using @{ } and fed to map() like any perl array

     reference.

 Round Robin

    This simple example will read lines from a file forever. When the last

    line is read, it will reopen the file and read the first one again.

        my $io = io 'file1.txt';

        $io->autoclose(1);

        while (my $line = $io->getline || $io->getline) {

          print $line;

        }

 Reading Backwards

    If you call the backwards method on an IO::All object, the getline and

    getlines will work in reverse. They will read the lines in the file

    from the end to the beginning.

        my @reversed;

        my $io = io('file1.txt');

        $io->backwards;

        while (my $line = $io->getline) {

          push @reversed, $line;

        }

    or more simply:

        my @reversed = io('file1.txt')->backwards->getlines;

    The backwards method returns the IO::All object so that you can chain

    the calls.

    NOTE: This operation requires that you have the File::ReadBackwards

    module installed.

 Client/Server Sockets

    IO::All makes it really easy to write a forking socket server and a

    client to talk to it.

    In this example, a server will return 3 lines of text, to every client

    that calls it. Here is the server code:

        use IO::All;

        my $socket = io(':12345')->fork->accept;

        $socket->print($_) while <DATA>;

        $socket->close;

        __DATA__

        On your mark,

        Get set,

        Go!

    Here is the client code:

        use IO::All;

        my $io = io('localhost:12345');

        print while $_ = $io->getline;

    You can run the server once, and then run the client repeatedly (in

    another terminal window). It should print the 3 data lines each time.

    Note that it is important to close the socket if the server is forking,

    or else the socket won't go out of scope and close.

 A Tiny Web Server

    Here is how you could write a simplistic web server that works with

    static and dynamic pages:

        perl -MIO::All -e 'io(":8080")->fork->accept->(sub { $_[0] < io(-x $1 ? "./$1 |" : $1) if /^GET \/(.*) / })'

    There is are a lot of subtle things going on here. First we accept a

    socket and fork the server. Then we overload the new socket as a code

    ref. This code ref takes one argument, another code ref, which is used

    as a callback.

    The callback is called once for every line read on the socket. The line

    is put into $_ and the socket itself is passed in to the callback.

    Our callback is scanning the line in $_ for an HTTP GET request. If one

    is found it parses the file name into $1. Then we use $1 to create an

    new IO::All file object... with a twist. If the file is executable

    (-x), then we create a piped command as our IO::All object. This

    somewhat approximates CGI support.

    Whatever the resulting object is, we direct the contents back at our

    socket which is in $_[0]. Pretty simple, eh?

 DBM Files

    IO::All file objects used as a hash reference, treat the file as a DBM

    tied to a hash. Here I write my DB record to STDERR:

        io("names.db")->{ingy} > io('=');

    Since their are several DBM formats available in Perl, IO::All picks

    the first one of these that is installed on your system:

        DB_File GDBM_File NDBM_File ODBM_File SDBM_File

    You can override which DBM you want for each IO::All object:

        my @keys = keys %{io('mydbm')->dbm('SDBM_File')};

 File Subclassing

    Subclassing is easy with IO::All. Just create a new module and use

    IO::All as the base class, like this:

        package NewModule;

        use IO::All -base;

    You need to do it this way so that IO::All will export the io function.

    Here is a simple recipe for subclassing:

    IO::Dumper inherits everything from IO::All and adds an extra method

    called dump, which will dump a data structure to the file we specify in

    the io function. Since it needs Data::Dumper to do the dumping, we

    override the open method to require Data::Dumper and then pass control

    to the real open.

    First the code using the module:

        use IO::Dumper;

        io('./mydump')->dump($hash);

    And next the IO::Dumper module itself:

        package IO::Dumper;

        use IO::All -base;

        use Data::Dumper;

        sub dump {

          my $self = shift;

          Dumper(@_) > $self;

        }

        1;

 Inline Subclassing

    This recipe does the same thing as the previous one, but without

    needing to write a separate module. The only real difference is the

    first line. Since you don't "use" IO::Dumper, you need to still call

    its import method manually.

        IO::Dumper->import;

        io('./mydump')->dump($hash);

        package IO::Dumper;

        use IO::All -base;

        use Data::Dumper;

        sub dump {

          my $self = shift;

          Dumper(@_) > $self;

        }

THE IO::ALL METHODS

    This section gives a full description of all of the methods that you

    can call on IO::All objects. The methods have been grouped into

    subsections based on object construction, option settings,

    configuration, action methods and support for specific modules.

 Object Construction and Initialization Methods

    new

      There are three ways to create a new IO::All object. The first is

      with the special function io which really just calls IO::All->new.

      The second is by calling new as a class method. The third is calling

      new as an object instance method. In this final case, the new objects

      attributes are copied from the instance object.

          io(file-descriptor);

          IO::All->new(file-descriptor);

          $io->new(file-descriptor);

      All three forms take a single argument, a file descriptor. A file

      descriptor can be any of the following:

          - A file name

          - A file handle

          - A directory name

          - A directory handle

          - A typeglob reference

          - A piped shell command. eg '| ls -al'

          - A socket domain/port.  eg 'perl.com:5678'

          - '-' means STDIN or STDOUT (depending on usage)

          - '=' means STDERR

          - '$' means an in memory filehandle object

          - '?' means a temporary file

          - A URI including: http, https, ftp and mailto

          - An IO::All object

      If you provide an IO::All object, you will simply get that same

      object returned from the constructor.

      If no file descriptor is provided, an object will still be created,

      but it must be defined by one of the following methods before it can

      be used for I/O:

    file

          io->file("path/to/my/file.txt");

      Using the file method sets the type of the object to file and sets

      the pathname of the file if provided.

      It might be important to use this method if you had a file whose name

      was '- ', or if the name might otherwise be confused with a directory

      or a socket. In this case, either of these statements would work the

      same:

          my $file = io('-')->file;

          my $file = io->file('-');

    dir

          io->dir($dir_name);

      Make the object be of type directory.

    socket

          io->socket("${domain}:${port}");

      Make the object be of type socket.

    link

          io->link($link_name);

      Make the object be of type link.

    pipe

          io->pipe($pipe_command);

      Make the object be of type pipe. The following three statements are

      equivalent:

          my $io = io('ls -l |');

          my $io = io('ls -l')->pipe;

          my $io = io->pipe('ls -l');

    dbm

      This method takes the names of zero or more DBM modules. The first

      one that is available is used to process the dbm file.

          io('mydbm')->dbm('NDBM_File', 'SDBM_File')->{author} = 'ingy';

      If no module names are provided, the first available of the following

      is used:

          DB_File GDBM_File NDBM_File ODBM_File SDBM_File

    mldbm

      Similar to the dbm method, except create a Multi Level DBM object

      using the MLDBM module.

      This method takes the names of zero or more DBM modules and an

      optional serialization module. The first DBM module that is available

      is used to process the MLDBM file. The serialization module can be

      Data::Dumper, Storable or FreezeThaw.

          io('mymldbm')->mldbm('GDBM_File', 'Storable')->{author} =

            {nickname => 'ingy'};

    string

      Make the object be an in memory filehandle. These are equivalent:

          my $io = io('$');

          my $io = io->string;

    temp

      Make the object represent a temporary file. It will automatically be

      open for both read and write.

    stdio

      Make the object represent either STDIN or STDOUT depending on how it

      is used subsequently. These are equivalent:

          my $io = io('-');

          my $io = io->stdin;

    stdin

      Make the object represent STDIN.

    stdout

      Make the object represent STDOUT.

    stderr

      Make the object represent STDERR.

    handle

          io->handle($io_handle);

      Forces the object to be created from an pre-existing IO handle. You

      can chain calls together to indicate the type of handle:

          my $file_object = io->file->handle($file_handle);

          my $dir_object = io->dir->handle($dir_handle);

    http

      Make the object represent an HTTP URI. Requires IO-All-LWP.

    https

      Make the object represent an HTTPS URI. Requires IO-All-LWP.

    ftp

      Make the object represent an FTP URI. Requires IO-All-LWP.

    mailto

      Make the object represent a mailto: URI. Requires IO-All-Mailto.

    If you need to use the same options to create a lot of objects, and

    don't want to duplicate the code, just create a dummy object with the

    options you want, and use that object to spawn other objects.

        my $lt = io->lock->tie;

        ...

        my $io1 = $lt->new('file1');

        my $io2 = $lt->new('file2');

    Since the new method copies attributes from the calling object, both

    $io1 and $io2 will be locked and tied.

 Option Setting Methods

    The following methods don't do any actual IO, but they specify options

    about how the IO should be done.

    Each option can take a single argument of 0 or 1. If no argument is

    given, the value 1 is assumed. Passing 0 turns the option off.

    All of these options return the object reference that was used to

    invoke them. This is so that the option methods can be chained

    together. For example:

        my $io = io('path/file')->tie->assert->chomp->lock;

    absolute

      Indicates that the pathname for the object should be made absolute.

          # Print the full path of the current working directory

          # (like pwd).

          use IO::All;

          print io->curdir->absolute;

    assert

      This method ensures that the path for a file or directory actually

      exists before the file is open. If the path does not exist, it is

      created.

      For example, here is a program called "create-cat-to" that outputs to

      a file that it creates.

          #!/usr/bin/perl

          # create-cat-to.pl

          # cat to a file that can be created.

          use strict;

          use warnings;

          use IO::All;

          my $filename = shift(@ARGV);

          # Create a file called $filename, including all leading components.

          io('-') > io->file($filename)->assert;

      Here's an example use of it:

          $ ls -l

          total 0

          $ echo "Hello World" | create-cat-to one/two/three/four.txt

          $ ls -l

          total 4

          drwxr-xr-x 3 shlomif shlomif 4096 2010-10-14 18:03 one/

          $ cat one/two/three/four.txt

          Hello World

          $

    autoclose

      By default, IO::All will close an object opened for input when EOF is

      reached. By closing the handle early, one can immediately do other

      operations on the object without first having to close it.

      This option is on by default, so if you don't want this behaviour,

      say so like this:

          $io->autoclose(0);

      The object will then be closed when $io goes out of scope, or you

      manually call $io->close.

    autoflush

      Proxy for IO::Handle::autoflush

    backwards

      Sets the object to 'backwards' mode. All subsequent getline

      operations will read backwards from the end of the file.

      Requires the File::ReadBackwards CPAN module.

    binary

      Adds :raw to the list of PerlIO layers applied after open, and

      applies it immediately on an open handle.

    chdir

      chdir() to the pathname of a directory object. When object goes out

      of scope, chdir back to starting directory.

    chomp

      Indicates that all operations that read lines should chomp the lines.

      If the separator method has been called, chomp will remove that value

      from the end of each record.

      Note that chomp may cause the following idiom to halt prematurely

      (e.g., if separator is \n (the default) and chomp is in effect, then

      this command will stop reading at the first blank line):

          while ( my $line = $io->getline ) {...}

      Try the following instead:

          while ( defined(my $line = $io->getline) ) {...}

    confess

      Errors should be reported with the very detailed Carp::confess

      function.

    deep

      Indicates that calls to the all family of methods should search

      directories as deep as possible.

    fork

      Indicates that the process should automatically be forked inside the

      accept socket method.

    lock

      Indicate that operations on an object should be locked using flock.

    rdonly

      This option indicates that certain operations like DBM and Tie::File

      access should be done in read-only mode.

    rdwr

      This option indicates that DBM and MLDBM files should be opened in

      read/write mode.

    relative

      Indicates that the pathname for the object should be made relative.

      If passed an argument, path will be made relative to passed argument.

    sort

      Indicates whether objects returned from one of the all methods will

      be in sorted order by name. True by default.

    tie

      Indicate that the object should be tied to itself, thus allowing it