Shell Programming and Scripting

Hello Everyone,

I'm struggiling with backup issues and need to sum up sizes of backup files monthly and add the result to the next month's sum recursively.
For this i have a well working script that i modified as i showed below and this part gives the sum of the file sizes under working directory. Using this i want to add each months' SUM recursively. When the SUM reaches a spesific value like %70 and %90 of a size of a magnetic tape i should give a warning (email probably) and then the SUM will be reset to zero. How can i use the script in a loop, could u please help, im not used to Looping.


### can i use the last part of the script again to sum up the every month's result by getting the result from recorded file by "cat"? ###

cat SUM_OF_FILES.txt > awk '/^-/ {total += $5} END {printf "%15.2f\n",total}'##as the sum value is in .txt the $5 part should be change as $0 or $1?##

if ["$a" -eq 50000000 ]; then ...
### i dont know how to calculate %70-90 of a value so i assigned a direct value here###

printf " ----ATTENTION!! 50 GBYTE or %70 of TAPE DRIVE IS FULL ----- ";

sendmail -bd .......

fi

if ["$a" -ge 70000000 ] ; then

printf " ----ATTENTION!! 70 GBYTE or %90 of TAPE DRIVE IS FULL ----- ";

sendmail -bd .......

$a == 0

fi


thanks in advanced..

Code:

cat SUM_OF_FILES.txt > awk '/^-/ {total += $5} END {printf "%15.2f\n",total}'

What is the above line supposed to do?
Where you trying to do this?

Code:

cat SUM_OF_FILES.txt   |   awk '/^-/ {total += $5} END {printf "%15.2f\n",total}'
 
or may be this
 
awk '/^-/ {total += $5} END {printf "%15.2f\n",total}' SUM_OF_FILES.txt

Cannot go through you description.
Just post what does the file SUM_OF_FILES.txt contain.
As you use >>, I presume you must be having more than one line in it.

first of all thanx for your replying,

With that line i want to fetch the last SUM value from SUM_OF_FILES.txt where I just want to save the monthly SUM results (but its not a must). In this txt file there will be each months sum results like
1515.45
1735.33
..
And as u said there will be many lines like above after appending each months sum to the txt file with ">>" so im not sure if awk can fetch the last line data from .txt file? if it's not possible then its not necessary to append monthly results to a new line. The worse I dont know how to use the last month's SUM ($a) in a comparison loop, thats poor that i coudlnt write a correct comparison loop

im sorry i forgot to tell very important point, im removing the back up files monthly from under the directory in which i wanna calculate the size of files under this directory. So assume that every month new backup data will be under the directory where i wanna use the script.