I have two files:
file1.txt:
FS Total Used Free Used%
/u01 10000 8000 2000 80%
/u02 10000 8000 2000 80%
/u03 10000 8000 2000 80%
/u04 10000 8000 2000 80%
/u05 10000 8000 2000 80%
/u06 10000 8000 2000 80%
/u07 10000 8000 2000 80%
/u10 10000 5000 5000 50%

file2.txt:
FS Adj
/u01 1,500
/u05 500
/u10 2,500

I would like to compare them using the first column in each file and create an output from both that looks like the following:

FS Total Used+Adj Free-Adj (Used+Adj)/Total
--------- -------- --------- --------- ---------
/u01 10,000 9,500 500 95%
/u02 10,000 8,000 2,000 80%
/u03 10,000 8,000 2,000 80%
/u04 10,000 8,000 2,000 80%
/u05 10,000 8,500 1,500 85%
/u06 10,000 8,000 2,000 80%
/u07 10,000 7,500 2,500 75%

Please note that all lines from file1.txt are listed, and column "adj" of file2.txt is added to column "Used" and subtracted from column "Free" of file1.txt only if there is a match.

I was able to produce this report only after loading these files into a database but I am sure I can do it using shell scripting with your help.

Thanks,
Omer