parse_mt940.rb

tokens = [/^:61/, /^:62F:/]

mt940 = <<MT940
:20:951110
:25:45050050/76198810
:28:27/01
:60F:C951016DEM84349,74
:61:951017D6800,NCHK16703074
:86:999PN5477SCHECK-NR. 0000016703074
:61:951017D620,3NSTON
:86:999PN0911DAUERAUFTR.NR. 14
:61:951017C18500,NCLRN
:86:999PN2406SCHECK
:61:951015D14220,NBOEN
:86:999PN0920WECHSEL
:61:951017D1507,NTRFN
:86:999PN0920SCHNELLUEB
:61:951024C4200,NMSCN
:86:999PN2506AUSSENH. NR. 1
:61:951017D19900,NTRFN
:86:999PN0907UEBERTRAG
:61:951017D400,NTRFN
:86:999PN0891BTX
:61:951018C3656,74NMSCN
:86:999PN0850EINZAHLG.N
:61:951019C23040,NMSCN
:86:999PN0812LT.ANLAGE
:61:951027D5862,14NCHKN
:86:999PN5329AUSLSCHECK
:62F:C951017DEM84437,04
MT940


def next_str(str, tokens)
  head = ''
  body = ''
  tail = str

  tail.each_line do |line|
    break if tokens.any?{ |token| token === line}
    head << line 
  end

  tail = tail[head.length..-1]

  in_body = false
  tail.each_line do |line|
    if in_body
      break if tokens.any?{ |token| token === line}
    else
      in_body = true
    end

    body << line 
  end

  tail = tail[body.length..-1]
  
  [head, body, tail]
end

tail = mt940
begin
  head, body, tail = next_str tail, tokens
  puts body
  puts '-'*10
end until tail == ''


=begin  # OUTPUT
:61:951017D6800,NCHK16703074
:86:999PN5477SCHECK-NR. 0000016703074
----------
:61:951017D620,3NSTON
:86:999PN0911DAUERAUFTR.NR. 14
----------
:61:951017C18500,NCLRN
:86:999PN2406SCHECK
----------
:61:951015D14220,NBOEN
:86:999PN0920WECHSEL
----------
:61:951017D1507,NTRFN
:86:999PN0920SCHNELLUEB
----------
:61:951024C4200,NMSCN
:86:999PN2506AUSSENH. NR. 1
----------
:61:951017D19900,NTRFN
:86:999PN0907UEBERTRAG
----------
:61:951017D400,NTRFN
:86:999PN0891BTX
----------
:61:951018C3656,74NMSCN
:86:999PN0850EINZAHLG.N
----------
:61:951019C23040,NMSCN
:86:999PN0812LT.ANLAGE
----------
:61:951027D5862,14NCHKN
:86:999PN5329AUSLSCHECK
----------
:62F:C951017DEM84437,04
----------
=end