I have a file with two lines like:
XXXXXXX20170412,bu.1519=1,bu.1124=2,bu.1284=3,bu.1767=13,bu.1869=15,bu.1784=16,bu.1473=32,bu.1264=43,bu.1758=96,bu.1649=122,bu.1345=140,bu.1268=215,bu.1246=516,bu.1876=601,
XXXXXXX20170413,bu.1123=1,bu.1767=27,bu.1784=32,bu.1473=57,bu.1869=41,bu.1264=91,bu.1284=54,bu.1758=191,bu.1268=387,bu.1345=319,bu.1649=322,bu.1246=1199,bu.1876=1383,
I want to get all strings exist in the first line (starting with string between ", and=" ) and not existing in the last line and append them to the end of the last line.