problem in algebraic expression

Shell Programming and Scripting
1 
count=`cat /filecount.txt | tail -1 |head -1| awk '{print $1}'`

exact_count=`expr $value \* 24`

i want to subtract

a="$exact_count" - "$count"

but its not taking o/p of "count" as number
$a is wrong answer

hence not getting proper output.

plz help me out

:confused:

2

In ksh:

# value=4                        
# (( exact_count = value * 24 )) 
# echo $exact_count
96
# count=10
# (( a = exact_count - count  ))    
# echo $a
86
3

Try:

a=$(( exact_count - count ))
4

its not working

i think there is problem in command

count=`cat /home/bsnl/sagar/filecount.txt | tail -1 |head -1| awk '{print $1}'`

its not taking o/p as number plz suggest some thing

---------- Post updated at 04:47 AM ---------- Previous update was at 04:46 AM ----------

ts not working

i think there is problem in command

count=`cat /home/bsnl/sagar/filecount.txt | tail -1 |head -1| awk '{print $1}'`

its not taking o/p of this as "number"

hence not working

o/p of script is like this