$ perl mycode.pl file1.txt param1 param2 > param_set1.out 
 $ perl mycode.pl file1.txt param3 param4 > param_set3.out
 $ perl mycode.pl file1.txt param4 param5 > param_set4.out

 $ cat param_set1.out param_set3.out param_set4.out  > final.out