key and ..

[Val Krem]

Hi all,
Sorry for asking such a basic question butI am trying  to merge two files(file1 and file2) and do some stuff. Merge the two files by the first column(key). Here is the description of files and what I would like to do.


file1

key c1   c2
1  759   939
2  345 154571
3  251 350711
4 3749  22159
5  676  76953
6   46    756


file2
key  p1    p2
1   759    939
2   345 154571
3   251 350711
4  3915  23254
5  7676  77953
7   256   4562

create file3
a) merge the two files by (key) that exit in  file1 and file2
b) create two variables dcp1 = c1- p1 and dcp2= c2-p2
c) sort file3 by dcp2(descending) and output

create file4:-  which exist in file1 but not in file2
create file5:-  that exist in file2 but not in file1;


Desired output files

file3
key   c1    c2     p1  p2     dcp1   dcp2
4   3749  22159  3915  23254  -166  -1095
5    676  76953  7676  77953 -7000  -1000
1    759    939   759    939     0      0
2    345 154571   345 154571     0      0
3    251 350711   251 350711     0      0

file4
key c1   p1
6   46   756

file5
key p1   p2
7  256  4562



Thank you in advance