In this i need to remove duplicates, the key to be used here is 123456789012 whic is coming from 5th column onwards in the input file.
Just to explain furthur - 5cloumn onwards in record 1 and record 3 are same hence in the output file i need to write only the first occurance of the record that is entry 1 and duplicate shoould not be present in the output file.
This file is having so many other records with different formats as well and once i sort we may loose the record order that is i need to remove only second ... occurance and not the first one. Please let me know if there is any other option available to remove the group of duplicates.
Secondly this file is having some 1000 records, the key will be different in each records and the order of the records should not change except the duplicates.