I'm new at this and frustratd because I know this must be simple but here goes. I'm trying to write a script that will give me the percentage of a particular field over multiple text files.

Each day I have around 1500 files that are generated. Each file has around 100 lines in it. The lines that I want have LOI in the first field. Each line has 13 fields. The last field either has 0001 (good) or 0002 (bad). I need to find the total lines with LOI and figure the percentage of 0002 of the total.

Getting the total is easy.

total=`grep LOI date* | cut -d" " -f 13 | wc -l`

and getting the bad...

bad=`grep LOI date* | cut -d" " -f 13 |grep 0002| wc -l`

date* gives me all the files for the day in question. So that counts all the records and gets them into a variables. Then I tried

expr $failed / $played

and it just gives me 0.

I then tried this in AWK. I can do this

gawk '/LOI/ {print $13 }' date* | wc -l | gawk '{print "total " $0}'

but can't figure out how to get both values into awk and manipulate them.
please help...