new

Open ISIS database

 my $isis = new Biblio::Isis(
        isisdb => './cds/cds',
        read_fdt => 1,
        include_deleted => 1,
        hash_filter => sub {
                my ($v,$field_number) = @_;
                $v =~ s#foo#bar#g;
        },
        debug => 1,
        join_subfields_with => ' ; ',
 );

Options are described below:

isisdb

This is full or relative path to ISIS database files which include common prefix of ".MST", and ".XRF" and optionally ".FDT" (if using "read_fdt" option) files.

In this example it uses "./cds/cds.MST" and related files.

read_fdt

Boolean flag to specify if field definition table should be read. It's off by default.

include_deleted

Don't skip logically deleted records in ISIS.

hash_filter

Filter code ref which will be used before data is converted to hash. It will receive two arguments, whole line from current field (in $_[0]) and field number (in $_[1]).

debug

Dump a lot of debugging output even at level 1. For even more increase level.

join_subfields_with

Define delimiter which will be used to join repeatable subfields. This option is included to support lagacy application written against version older than 0.21 of this module. By default, it disabled. See "to_hash".

ignore_empty_subfields

Remove all empty subfields while reading from ISIS file.

count

Return number of records in database

  print $isis->count;

fetch

Read record with selected MFN

  my $rec = $isis->fetch(55);

Returns hash with keys which are field names and values are unpacked values for that field like this:

  $rec = {
    '210' => [ '^aNew York^cNew York University press^dcop. 1988' ],
    '990' => [ '2140', '88', 'HAY' ],
  };

mfn

Returns current MFN position

  my $mfn = $isis->mfn;

to_ascii

Returns ASCII output of record with specified MFN

  print $isis->to_ascii(42);

This outputs something like this:

  210   ^aNew York^cNew York University press^dcop. 1988
  990   2140
  990   88
  990   HAY

If "read_fdt" is specified when calling "new" it will display field names from ".FDT" file instead of numeric tags.

to_hash

Read record with specified MFN and convert it to hash

  my $hash = $isis->to_hash($mfn);

It has ability to convert characters (using "hash_filter") from ISIS database before creating structures enabling character re-mapping or quick fix-up of data.

This function returns hash which is like this:

  $hash = {
    '210' => [
               {
                 'c' => 'New York University press',
                 'a' => 'New York',
                 'd' => 'cop. 1988'
               }
             ],
    '990' => [
               '2140',
               '88',
               'HAY'
             ],
  };

You can later use that hash to produce any output from ISIS data.

If database is created using IsisMarc, it will also have to special fields which will be used for identifiers, "i1" and "i2" like this:

  '200' => [
             {
               'i1' => '1',
               'i2' => ' '
               'a' => 'Goa',
               'f' => 'Valdo D\'Arienzo',
               'e' => 'tipografie e tipografi nel XVI secolo',
             }
           ],

In case there are repeatable subfields in record, this will create following structure:

  '900' => [ {
        'a' => [ 'foo', 'bar', 'baz' ],
  }]

Or in more complex example of

  902   ^aa1^aa2^aa3^bb1^aa4^bb2^cc1^aa5

it will create

  902   => [
        { a => ["a1", "a2", "a3", "a4", "a5"], b => ["b1", "b2"], c => "c1" },
  ],

This behaviour can be changed using "join_subfields_with" option to "new", in which case "to_hash" will always create single value for each subfield. This will change result to:

This method will also create additional field 000 with MFN.

There is also more elaborative way to call "to_hash" like this:

  my $hash = $isis->to_hash({
        mfn => 42,
        include_subfields => 1,
  });

Each option controll creation of hash:

mfn

Specify MFN number of record

include_subfields

This option will create additional key in hash called "subfields" which will have original record subfield order and index to that subfield like this:

  902   => [ {
        a => ["a1", "a2", "a3", "a4", "a5"],
        b => ["b1", "b2"],
        c => "c1",
        subfields => ["a", 0, "a", 1, "a", 2, "b", 0, "a", 3, "b", 1, "c", 0, "a", 4],
  } ],
    

join_subfields_with

Define delimiter which will be used to join repeatable subfields. You can specify option here instead in "new" if you want to have per-record control.

hash_filter

You can override "hash_filter" defined in "new" using this option.

tag_name

Return name of selected tag

 print $isis->tag_name('200');

read_cnt

Read content of ".CNT" file and return hash containing it.

  print Dumper($isis->read_cnt);

This function is not used by module (".CNT" files are not required for this module to work), but it can be useful to examine your index (while debugging for example).

unpack_cnt

Unpack one of two 26 bytes fixed length record in ".CNT" file.

Here is definition of record:

 off key        description                             size
  0: IDTYPE     BTree type                              s
  2: ORDN       Nodes Order                             s
  4: ORDF       Leafs Order                             s
  6: N          Number of Memory buffers for nodes      s
  8: K          Number of buffers for first level index s
 10: LIV        Current number of Index Levels          s
 12: POSRX      Pointer to Root Record in N0x           l
 16: NMAXPOS    Next Available position in N0x          l
 20: FMAXPOS    Next available position in L0x          l
 24: ABNORMAL   Formal BTree normality indicator        s
 length: 26 bytes

This will fill $self object under "cnt" with hash. It's used by "read_cnt".