Shell Programming and Scripting

1) There is only one file to be scaned

2)This file will be scaned after every 1 hour.

3) Let us suppose we scan the file right now . And suppose this gives us a count of ERROR as 5 . We will assume this as initial count.

4) After 1 hour we will scan the same log file once again. Let us suppose this gives the count as 10. Now we have to compare this 10 with the last count 5 .

5) Now "10" is the final count and the "5" is the initial count.

6) In the next scan , "10" will become initial count and some new number will become the final count.

7) As we created the "a.log" file earlier. I want to move "10" to this "a.log". So, that I can compare in the below mention way

Code:

 
#!/bin/sh
if [  ! -f a.log ]; then
   touch a.log
iCOUNT=`a.log | wc -l`
fCOUNT=`grep -c ERROR b.log`
if [ ${fCOUNT} -gt ${iCOUNT} ]; then
   echo "1"
else
   echo "0"
fi
$fCOUNT > a.log
else
iCOUNT=`a.log | wc -l`
fCOUNT=`grep -c ERROR b.log`
if [ ${fCOUNT} -gt ${iCOUNT} ]; then
  echo "1"
else
  echo "0"
fi
fi

a.log will have only the number . I guess I am making a mistake in

iCOUNT=`a.log | wc -l`

Please Advice

Say your filename is a.log
For the first run, iCOUNT and fCOUNT will be same. Hence o/p will be 0.
Script will store the fCOUNT to tmp_file.log and in next run, it will pick iCOUNT from this file. Try following code.

Code:

#!/bin/sh
if [  ! -f a.log ]; then
   touch a.log
fi

fCOUNT=`grep -c ERROR a.log`

if [ ! -f tmp_file.log ]; then
   iCOUNT=$fCOUNT
else
   read iCOUNT < tmp_file.log
fi

if [ ${fCOUNT} -gt ${iCOUNT} ]; then
   echo "1"
else
   echo "0"
fi

echo $fCOUNT > tmp_file.log

Code:

 
read iCOUNT < tmp_file.log
 
echo $fCOUNT > tmp_file.log
 
iCOUNT=$fCOUNT

I would really appreciate if you could explain the purposes of the above mentiond commands

Regards

read iCOUNT < tmp_file.log ---> Reads content of tmp_file.log to iCOUNT variable
echo $fCOUNT > tmp_file.log --> Writing fCOUNT to tmp_file.log
iCOUNT=$fCOUNT --> Assigning / Copying value at fCOUNT to iCOUNT