marc_copy(MARC_PATH, JSON_PATH, [equals: REGEX])¶

Copy this MARC fields referred by a MARC_PATH to a JSON_PATH. When an "equals" value has been provided, then only the MARC_PATHs with a value equal to "equals" will be copied to JSON_PATH. When the MARC_PATH points to a subfield, then the subfield value need to match "equals". When the MARC_PATH points multiple subfields, then a concatinated string value needs to match "equals":

    Data:
    100 $aMy$bField.
    # copy only the 100 fields which have a $a subfield
    marc_copy(100a,tmp)
    # copy only the 100 fields with have a $a subfield matching 'My'
    marc_copy(100a,tmp,equals:"My")
    # copy only the 100 fields with have a concatinated string value 'MyField.'
    # (equals is an regex, the period "." needs to be escaped "\.")
    marc_copy(100,tmp,equals:"MyField\.")
    # copy only the 100 fields which have a "." at the end
    marc_copy(100,tmp,equals:"\.$")

More examples:

    # Copy all the 300 fields
    marc_copy(300,tmp)
    # Copy all the 300 fields with indicator 1 = 1
    marc_copy(300[1],tmp)
    # Copy all the 300 fields which have subfield c
    marc_copy(300c,tmp)
    # Copy all the 300 fields which have subfield c equal to 'ABC'
    marc_copy(300c,tmp,equals:"^ABC")
    The JSON_PATH C<tmp> will contain an array with one item per field that was copied.
    Each item is a hash containing the following fields:
      tmp.*.tag        - The names of the MARC field
      tmp.*.ind1       - The value of the first indicator
      tmp.*.ind2       - The value of the second indicator
      tmp.*.subfields  - An array of subfield items. Each subfield item is a
                         hash of the subfield code and subfield value
    E.g.
        tmp:
        - tag: '300'
          ind1: ' '
          ind2: ' '
          subfields:
          - a: 'blabla:'
          - v: 'test123'
          - c: 'ok123'
    These JSON paths can be used like:
        # Set the first indicator of all 300 fields
        do marc_each(var:this)
          if all_match(this.tag,300)
            # Set the first indicator to 1
            set_field(this.ind1,1)
            marc_paste(this)
          end
        end
        # Capitalize all the v subfields of 300
        do marc_each(var:this)
            if all_match(this.tag,300)
             do list(path:this.subfields, var:loop)
                if (exists(loop.v))
                    upcase(loop.v)
                end
             end
             marc_paste(this)
          end
        end