AnyData

AnyData(3pm)          User Contributed Perl Documentation         AnyData(3pm)



NAME
       AnyData - (DEPRECATED) easy access to data in many formats

SYNOPSIS
        use AnyData;
        my $table = adTie( 'CSV','my_db.csv','o',            # create a table
                        {col_names=>'name,country,sex'}
                      );
        $table->{Sue} = {country=>'de',sex=>'f'};         # insert a row
        delete $table->{Tom};                             # delete a single row
        $str  = $table->{Sue}->{country};                 # select a single value
        while ( my $row = each %$table ) {                # loop through table
          print $row->{name} if $row->{sex} eq 'f';
        }
        $rows = $table->{{age=>'> 25'}};                  # select multiple rows
        delete $table->{{country=>qr/us|mx|ca/}};         # delete multiple rows
        $table->{{country=>'Nz'}}={country=>'nz'};        # update multiple rows
        my $num = adRows( $table, age=>'< 25' );          # count matching rows
        my @names = adNames( $table );                    # get column names
        my @cars = adColumn( $table, 'cars' );            # group a column
        my @formats = adFormats();                        # list available parsers
        adExport( $table, $format, $file, $flags );       # save in specified format
        print adExport( $table, $format, $flags );        # print to screen in format
        print adDump($table);                             # dump table to screen
        undef $table;                                     # close the table

        #adConvert( $format1, $file1, $format2, $file2 );  # convert btwn formats
        #print adConvert( $format1, $file1, $format2 );    # convert to screen

DESCRIPTION
       The rather wacky idea behind this module and its sister module
       DBD::AnyData is that any data, regardless of source or format should be
       accessible and modifiable with the same simple set of methods.  This
       module provides a multidimensional tied hash interface to data in a
       dozen different formats. The DBD::AnyData module adds a DBI/SQL
       interface for those same formats.

       Both modules provide built-in protections including appropriate
       flocking() for all I/O and (in most cases) record-at-a-time access to
       files rather than slurping of entire files.

       Currently supported formats include general format flat files (CSV,
       Fixed Length, etc.), specific formats (passwd files, httpd logs, etc.),
       and a variety of other kinds of formats (XML, Mp3, HTML tables).  The
       number of supported formats will continue to grow rapidly since there
       is an open API making it easy for any author to create additional
       format parsers which can be plugged in to AnyData itself and thereby be
       accessible by either the tiedhash or DBI/SQL interface.

PREREQUISITES
       The AnyData.pm module itself is pure Perl and does not depend on
       anything other than modules that come standard with Perl.  Some formats
       and some advanced features require additional modules: to use the
       remote ftp/http features, you must have the LWP bundle installed; to
       use the XML format, you must have XML::Parser and XML::Twig installed;
       to use the HTMLtable format for reading, you must have HTML::Parser and
       HTML::TableExtract installed but you can use the HTMLtable for writing
       with just the standard CGI module.  To use DBI/SQL commands, you must
       have DBI, DBD::AnyData, SQL::Statement and DBD::File installed.

USAGE
       The AnyData module imports eight methods (functions):

         adTie()     -- create a new table or open an existing table
         adExport()  -- save an existing table in a specified format
         adConvert() -- convert data in one format into another format
         adFormats() -- list available formats
         adNames()   -- get the column names of a table
         adRows()    -- get the number of rows in a table or query
         adDump()    -- display the data formatted as an array of rows
         adColumn()  -- group values in a single column

       The adTie() command returns a special tied hash.  The tied hash can
       then be used to access and/or modify data.  See below for details

       With the exception of the XML, HTMLtable, and ARRAY formats, the
       adTie() command saves all modifications of the data directly to file as
       they are made.  With XML and HTMLtable, you must make your
       modifications in memory and then explicitly save them to file with
       adExport().

   adTie()
        my $table = adTie( $format, $data, $open_mode, $flags );

       The adTie() command creates a reference to a multidimensional tied
       hash. In its simplest form, it simply reads a file in a specified
       format into the tied hash:

        my $table = adTie( $format, $file );

       $format is the name of any supported format 'CSV','Fixed','Passwd',
       etc.  $file is the name of a relative or absolute path to a local file

       e.g.
            my $table = adTie( 'CSV', '/usr/me/myfile.csv' );

       this creates a tied hash called $table by reading data in the CSV
       (comma separated values) format from the file 'myfile.csv'.

       The hash reference resulting from adTie() can be accessed and modified
       as follows:

        use AnyData;
        my $table = adTie( $format, $file );
        $table->{$key}->{$column};                       # select a value
        $table->{$key} = {$col1=>$val1,$col2=>$val2...}; # update a row
        delete $table->{$key};                           # delete a row
        while(my $row = each %$table) {                  # loop through rows
          print $row->{$col1} if $row->{$col2} ne 'baz';
        }

       The thing returned by adTie ($table in the example) is not an object,
       it is a reference to a tied hash. This means that hash operations such
       as exists, values, keys, may be used, keeping in mind that this is a
       *reference* to a tied hash so the syntax would be

           for( keys %$table ) {...}
           for( values %$table ) {...}

       Also keep in mind that if the table is really large, you probably do
       not want to use keys and values because they create arrays in memory
       containing data from every row in the table.  Instead use 'each' as
       shown above since that cycles through the file one record at a time and
       never puts the entire table into memory.

       It is also possible to use more advanced searching on the hash, see
       "Multiple Row Operations" below.

       In addition to the simple adTie($format,$file), there are other ways to
       specify additional information in the adTie() command.  The full syntax
       is:

        my $table = adTie( $format, $data, $open_mode, $flags );

        The $data parameter allows you to read data from remote files accessible by
        http or ftp, see "Using Remote Files" below.  It also allows you to treat
        strings and arrays as data sources without needing a file at all, see
        "Working with Strings and Arrays" below.

       The optional $mode parameter defaults to 'r' if none is supplied or
       must be one of

        'r' read      # read only access
        'u' update    # read/write access
        'c' create    # create a new file unless it already exists
        'o' overwrite # create a new file, overwriting any that already exist

       The $flags parameter allows you to specify additional information such
       as column names.  See the sections in "Further Details" below.

       With the exception of the XML, HTMLtable, and ARRAY formats, the
       adTie() command saves all modifications of the data directly to file as
       they are made.  With XML and HTMLtable, you must make your
       modifications in memory and then explicitly save them to file with
       adExport().

   adConvert()
        adConvert( $format1, $data1, $format2, $file2, $flags1, $flags2 );

        or

        print adConvert( $format1, $data1, $format2, undef, $flags1, $flags2 );

        or

        my $aryref = adConvert( $format1, $data1, 'ARRAY', undef, $flags1 );

        This method converts data in any supported format into any other supported
        format.  The resulting data may either be saved to a file (if $file2 is
        supplied as a parameter) or sent back as  a string to e.g. print the data
        to the screen in the new format (if no $file2 is supplied), or sent back
        as an array reference if $format2 is 'ARRAY'.

        Some examples:

          # convert a CSV file into an XML file
          #
          adConvert('CSV','foo.csv','XML','foo.xml');

          # convert a CSV file into an HTML table and print it to the screen
          #
          print adConvert('CSV','foo.csv','HTMLtable');

          # convert an XML string into a CSV file
          #
          adConvert('XML', ["<x><motto id='perl'>TIMTOWTDI</motto></x>"],
                    'CSV','foo.csv'
                   );

          # convert an array reference into an XML file
          #
          adConvert('ARRAY', [['id','motto'],['perl','TIMTOWTDI']],
                    'XML','foo.xml'
                   );

          # convert an XML file into an array reference
          #
          my $aryref = adConvert('XML','foo.xml','ARRAY');

        See section below "Using strings and arrays" for details.

   adExport()
        adExport( $table, $format, $file, $flags );

        or

        print adExport( $table, $format );

        or

        my $aryref = adExport( $table, 'ARRAY' );

        This method converts an existing tied hash into another format and/or
        saves the tied hash as a file in the specified format.

        Some examples:

          all assume a previous call to my $table= adTie(...);

          # export table to an XML file
          #
          adExport($table','XML','foo.xml');

          # export table to an HTML string and print it to the screen
          #
          print adExport($table,'HTMLtable');

          # export the table to an array reference
          #
          my $aryref = adExport($table,'ARRAY');

        See section below "Using strings and arrays" for details.

   adNames()
        my $table = adTie(...);
        my @column_names = adNames($table);

       This method returns an array of the column names for the specified
       table.

   adRows()
        my $table = adTie(...);
        adRows( $table, %search_hash );

       This method takes an AnyData tied hash created with adTie() and counts
       the rows in the table that match the search hash.

       For example, this snippet returns a count of the rows in the file that
       contain the specified page in the request column

         my $hits = adTie( 'Weblog', 'access.log');
         print adRows( $hits , request => 'mypage.html' );

       The search hash may contain multiple search criteria, see the section
       on multiple row operations below.

       If the search_hash is omitted, it returns a count of all rows.

   adColumn()
        my @col_vals = adColumn( $table, $column_name, $distinct_flag );

       This method returns an array of values taken from the specified column.
       If there is a distinct_flag parameter, duplicates will be eliminated
       from the list.

       For example, this snippet returns a unique list of the values in the
       'player' column of the table.

         my $game = adTie( 'Pipe','games.db' );
         my @players  = adColumn( $game, 'player', 1 );

   adDump()
         my $table = adTie(...);
         print adDump($table);

       This method prints the raw data in the table.  Column names are printed
       inside angle brackets and separated by colons on the first line, then
       each row is printed as a list of values inside square brackets.

   adFormats()
         print "$_\n for adFormats();

       This method shows the available format parsers, e.g. 'CSV', 'XML', etc.
       It looks in your @INC for the .../AnyData/Format directory and prints
       the names of format parsing files there.  If the parser requires
       further modules (e.g. XML requires XML::Parser) and you do not have the
       additional modules installed, the format will not work even if listed
       by this command.  Otherwise, all formats should work as described in
       this documentation.

FURTHER DETAILS
   Column Names
       Column names may be assigned in three ways:

        * pre  -- The format parser preassigns column
                  names (e.g. Passwd files automatically have
                  columns named 'username', 'homedir', 'GID', etc.).

        * user -- The user specifies the column names as a comma
                  separated string associated with the key 'cols':

                  my $table = adTie( $format,
                                     $file,
                                     $mode,
                                     {cols=>'name,age,gender'}
                                   );

        * auto -- If there is no preassigned list of column names
                  and none defined by the user, the first line of
                  the file is treated as a list of column names;
                  the line is parsed according to the specific
                  format (e.g. CSV column names are a comma-separated
                  list, Tab column names are a tab separated list);

       When creating a new file in a format that does not preassign column
       names, the user *must* manually assign them as shown above.

       Some formats have special rules for assigning column names
       (XML,Fixed,HTMLtable), see the sections below on those formats.

   Key Columns
       The AnyData modules support tables that have a single key column that
       uniquely identifies each row as well as tables that do not have such
       keys.  For tables where there is a unique key, that key may be assigned
       in three ways:

        * pre --  The format parser automatically preassigns the
                  key column name e.g. Passwd files automatically
                  have 'username' as the key column.

        * user -- The user specifies the key column name:

                  my $table = adTie( $format,
                                     $file,
                                     $mode,
                                     {key=>'country'}
                                   );

        * auto    If there is no preassigned key column and the user
                  does not define one, the first column becomes the
                  default key column

   Format Specific Details
        For full details, see the documentation for AnyData::Format::Foo
        where Foo is any of the formats listed in the adFormats() command
        e.g. 'CSV', 'XML', etc.

        Included below are only some of the more important details of the
        specific parsers.

       Fixed Format
           When using the Fixed format for fixed length records you must
           always specify a pattern indicating the lengths of the fields.
           This should be a string as would be passed to the unpack() function
           to unpack the records in your Fixed length definition:

            my $t = adTie( 'Fixed', $file, 'r', {pattern=>'A3 A7 A9'} );

           If you want the column names to appear on the first line of a Fixed
           file, they should be in comma-separated format, not in Fixed
           format.  This is different from other formats which use their own
           format to display the column names on the first line.  This is
           necessary because the name of the column might be longer than the
           length of the column.

       XML Format
            The XML format does not allow you to specify column names as a flag,
            rather you specify a "record_tag" and the column names are determined
            from the contents of the tag.  If no record_tag is specified, the
            record tag will be assumed to be the first child of the root of the
            XML tree.  That child and its structure will be determined from the
            DTD if there is one, or from the first occurring record if there is
            no DTD.

           For simple XML, no flags are necessary:

            <table>
               <row row_id="1"><name>Joe</name><location>Seattle</location></row>
               <row row_id="2"><name>Sue</name><location>Portland</location></row>
            </table>

           The record_tag will default to the first child, namely "row".  The
           column names will be generated from the attributes of the record
           tag and all of the tags included under the record tag, so the
           column names in this example will be "row_id","name","location".

           If the record_tag is not the first child, you will need to specify
           it.  For example:

            <db>
              <table table_id="1">
                <row row_id="1"><name>Joe</name><location>Seattle</location></row>
                <row row_id="2"><name>Sue</name><location>Portland</location></row>
              </table>
              <table table_id="2">
                <row row_id="1"><name>Bob</name><location>Boise</location></row>
                <row row_id="2"><name>Bev</name><location>Billings</location></row>
              </table>
            </db>

           In this case you will need to specify "row" as the record_tag since
           it is not the first child of the tree.  The column names will be
           generated from the attributes of row's parent (if the parent is not
           the root), from row's attributes and sub tags, i.e.
           "table_id","row_id","name","location".

           When exporting XML, you can specify a DTD to control the output.
           For example, if you import a table from CSV or from an Array, you
           can output as XML and specify which of the columns become tags and
           which become attributes and also specify the nesting of the tags in
           your DTD.

           The XML format parser is built on top of Michel Rodriguez's
           excellent XML::Twig which is itself based on XML::Parser.
           Parameters to either of those modules may be passed in the flags
           for adTie() and the other commands including the "prettyPrint" flag
           to specify how the output XML is displayed and things like
           ProtocolEncoding.  ProtocolEncoding defaults to 'ISO-8859-1', all
           other flags keep the defaults of XML::Twig and XML::Parser.  See
           the documentation of those modules for details;

            CAUTION: Unlike other formats, the XML format does not save changes to
            the file as they are entered, but only saves the changes when you explicitly
            request them to be saved with the adExport() command.

       HTMLtable Format
            This format is based on Matt Sisk's excelletn HTML::TableExtract.

            It can be used to read an existing table from an html page, or to
            create a new HTML table from any data source.

            You may control which table in an HTML page is used with the column_names,
            depth and count flags.

            If a column_names flag is passed, the first table that contains those names
            as the cells in a row will be selected.

            If depth and or count parameters are passed, it will look for tables as
            specified in the HTML::TableExtract documentation.

            If none of column_names, depth, or count flags are passed, the first table
            encountered in the file will be the table selected and its first row will
            be used to determine the column names for the table.

            When exporting to an HTMLtable, you may pass flags to specify properties
            of the whole table (table_flags), the top row containing the column names
            (top_row_flags), and the data rows (data_row_flags).  These flags follow
            the syntax of CGI.pm table constructors, e.g.:

            print adExport( $table, 'HTMLtable', {
                table_flags    => {Border=>3,bgColor=>'blue'};
                top_row_flags  => {bgColor=>'red'};
                data_row_flags => {valign='top'};
            });

            The table_flags will default to {Border=>1,bgColor=>'white'} if none
            are specified.

            The top_row_flags will default to {bgColor=>'#c0c0c0'} if none are
            specified;

            The data_row_flags will be empty if none are specified.

            In other words, if no flags are specified the table will print out with
            a border of 1, the column headings in gray, and the data rows in white.

            CAUTION: This module will *not* preserve anything in the html file except
            the selected table so if your file contains more than the selected table,
            you will want to use adTie() to read the table and then adExport() to write
            the table to a different file.  When using the HTMLtable format, this is the
            only way to preserve changes to the data, the adTie() command will *not*
            write to a file.

   Multiple Row Operations
       The AnyData hash returned by adTie() may use either single values as
       keys, or a reference to a hash of comparisons as a key.  If the key to
       the hash is a single value, the hash operates on a single row but if
       the key to the hash is itself a hash reference, the hash operates on a
       group of rows.

        my $num_deleted = delete $table->{Sue};

       This example deletes a single row where the key column has the value
       'Sue'.  If multiple rows have the value 'Sue' in that column, only the
       first is deleted.  It uses a simple string as a key, therefore it
       operates on only a single row.

        my $num_deleted = delete $table->{ {name=>'Sue'} };

       This example deletes all rows where the column 'name' is equal to
       'Sue'.  It uses a hashref as a key and therefore operates on multiple
       rows.

       The hashref used in this example is a single column comparison but the
       hashref could also include multiple column comparisons.  This deletes
       all rows where the the values listed for the country, gender, and age
       columns are equal to those specified:

         my $num_deleted = delete $table->{{ country => 'us',
                                              gender => 'm',
                                                 age => '25'
                                          }}

       In addition to simple strings, the values may be specified as regular
       expressions or as numeric or alphabetic comparisons.  This will delete
       all North American males under the age of 25:

         my $num_deleted = delete $table->{{ country => qr/mx|us|ca/,
                                             gender  => 'm',
                                             age     => '< 25'
                                          }}

       If numeric or alphabetic comparisons are used, they should be a string
       with the comparison operator separated from the value by a space, e.g.
       '> 4' or 'lt b'.

       This kind of search hashref can be used not only to delete multiple
       rows, but also to update rows.  In fact you *must* use a hashref key in
       order to update your table.  Updating is the only operation that can
       not be done with a single string key.

       The search hashref can be used with a select statement, in which case
       it returns a reference to an array of rows matching the criteria:

        my $male_players = $table->{{gender=>'m'}};
        for my $player( @$male_players ) { print $player->{name},"\n" }

       This should be used with caution with a large table since it gathers
       all of the selected rows into an array in memory.  Again, 'each' is a
       much better way for large tables.  This accomplishes the same thing as
       the example above, but without ever pulling more than a row into memory
       at a time:

        while( my $row= each %$table ) {
          print $row->{name}, "\n" if $row->{gender}=>'m';
        }

       Search criteria for multiple rows can also be used with the adRows()
       function:

         my $num_of_women = adRows( $table, gender => 'w' );

       That does *not* pull the entire table into memory, it counts the rows a
       record at a time.

   Using Remote Files
       If the first file parameter of adTie() or adConvert() begins with
       "http://" or "ftp://", the file is treated as a remote URL and the LWP
       module is called behind the scenes to fetch the file.  If the files are
       in an area that requires authentication, that may be supplied in the
       $flags parameter.

       For example:

         # read a remote file and access it via a tied hash
         #
         my $table = adTie( 'XML', 'http://www.foo.edu/bar.xml' );

         # same with username/password
         #
         my $table = ( 'XML', 'ftp://www.foo.edu/pub/bar.xml', 'r'
                       { user => 'me', pass => 'x7dy4'
                     );

         # read a remote file, convert it to an HTML table, and print it
         #
         print adConvert( 'XML', 'ftp://www.foo.edu/pub/bar.xml', 'HTMLtable' );

   Using Strings and Arrays
       Strings and arrays may be used as either the source of data input or as
       the target of data output.  Strings should be passed as the only
       element of an array reference (in other words, inside square brackets).
       Arrays should be a reference to an array whose first element is a
       reference to an array of column names and whose succeeding elements are
       references to arrays of row values.

       For example:

         my $table = adTie( 'XML', ["<x><motto id='perl'>TIMTOWTDI</motto></x>"] );

         This uses the XML format to parse the supplied string and returns a tied
         hash to the resulting table.


         my $table = adTie( 'ARRAY', [['id','motto'],['perl','TIMTOWTDI']] );

         This uses the column names "id" and "motto" and the supplied row values
         and returns a tied hash to the resulting table.

       It is also possible to use an empty array to create a new empty tied
       hash in any format, for example:

         my $table = adTie('XML',[],'c');

         creates a new empty tied hash;

       See adConvert() and adExport() for further examples of using strings
       and arrays.

   Ties, Flocks, I/O, and Atomicity
       AnyData provides flocking which works under the limitations of flock --
       that it only works if other processes accessing the files are also
       using flock and only on platforms that support flock.  See the flock()
       man page for details.

       Here is what the user supplied open modes actually do:

        r = read only  (LOCK_SH)  O_RDONLY
        u = update     (LOCK_EX)  O_RDWR
        c = create     (LOCK_EX)  O_CREAT | O_RDWR | O_EXCL
        o = overwrite  (LOCK_EX)  O_CREAT | O_RDWR | O_TRUNC

       When you use something like "my $table = adTie(...)", it opens the file
       with a lock and leaves the file and lock open until 1) the hash
       variable ($table) goes out of scope or 2) the hash is undefined (e.g.
       "undef $table") or 3) the hash is re-assigned to another tie.  In all
       cases the file is closed and the lock released.

       If adTie is called without creating a tied hash variable, the file is
       closed and the lock released immediately after the call to adTie.

        For example:  print adTie('XML','foo.xml')->{main_office}->{phone}.

        That obtains a shared lock, opens the file, retrieves the one value
        requested, closes the file and releases the lock.

       These two examples accomplish the same thing but the first example
       opens the file once, does all of the deletions, keeping the exclusive
       lock in place until they are all done, then closes the file.  The
       second example opens and closes the file three times, once for each
       deletion and releases the exclusive lock between each deletion:

        1. my $t = adTie('Pipe','games.db','u');
           delete $t->{"user$_"} for (0..3);
           undef $t; # closes file and releases lock

        2. delete adTie('Pipe','games.db','u')->{"user$_"} for (0..3);
           # no undef needed since no hash variable created

   Deletions and Packing
       In order to save time and to prevent having to do writes anywhere
       except at the end of the file, deletions and updates are *not* done at
       the time of issuing a delete command.  Rather when the user does a
       delete, the position of the deleted record is stored in a hash and when
       the file is saved to disk, the deletions are only then physically
       removed by packing the entire database.  Updates are done by inserting
       the new record at the end of the file and marking the old record for
       deletion.  In the normal course of events, all of this should be
       transparent and you'll never need to worry about it.  However, if your
       server goes down after you've made updates or deletions but before
       you've saved the file, then the deleted rows will remain in the
       database and for updates there will be duplicate rows -- the old non
       updated row and the new updated row.  If you are worried about this
       kind of event, then use atomic deletes and updates as shown in the
       section above.  There's still a very small possibility of a crash in
       between the deletion and the save, but in this case it should impact at
       most a single row.  (BIG thanks to Matthew Wickline for suggestions on
       handling deletes)

MORE HELP
       See the README file and the test.pl included with the module for
       further examples.

       See the AnyData/Format/*.pm PODs for further details of specific
       formats.

       For further support, please use comp.lang.perl.modules

ACKNOWLEDGEMENTS
       Special thanks to Andy Duncan, Tom Lowery, Randal Schwartz, Michel
       Rodriguez, Jochen Wiedmann, Tim Bunce, Alligator Descartes, Mathew
       Persico, Chris Nandor, Malcom Cook and to many others on the DBI
       mailing lists and the clp* newsgroups.

AUTHOR & COPYRIGHT
        Jeff Zucker <jeff@vpservices.com>

        This module is copyright (c), 2000 by Jeff Zucker.
        Some changes (c) 2012 Sven Dowideit L<mailto:SvenDowideit@fosiki.com>
        It may be freely distributed under the same terms as Perl itself.



perl v5.20.2                      2015-01-28                      AnyData(3pm)