UNIX for Dummies Questions & Answers

Hi all...

the last two weeks have been very educational... I went through a bunch of websites about linux and its commands.. still not have mastered it nor its many operators ... and symbols. I wish I had more time to dig to the next and unix.com but I m on a deadline for this project.

I have a file with many lines like the following

Code:

 
1259618998,5708852666@ZZZZ.com,txt@YYY.com,0
1259618998,5803013030@ZZZZ.com,txt@YYY.com,0
1259618998,5805300577@ZZZ.com,txt@YYY.com,0

So the pattern is

Code:

 
EPoch_Time,From_Address,To_Address,Count

Well heres what I am told to do...
I
When this script is run it should check each line and compare that line's Epochtime with the current Epcohtime. If 15 mins have passed by then it should increase count value by 1.
II
It should check the count value and if its mod (count/5) is qual to '0'. [ eg if (mod(count/5) == 0) ]
If false increase the count value by 1
If true then I have to send mail to abc.def@xxx.com. Telling which 'from' and 'to' mail address 'combination' is still in the Q.

I have no idea how to use the ^ / $ or any other operator. Any help will be appreciated.
Thanks

For I:
Store the current time in a variable, compare the current time and the time on the file using an if loop, based on the result set the counter value to 1 more.

Please explain the format of the first field of the text assuming it is the time in the input file and the counter operation as there are 2 ways of it working in I & II.

I dont know how to extract string from the line mentioned. Could you tell me how to do it. so that i could store it in variable eg

VAR1 = Epochtime
VAR2 = Count.

Also i dont know how to replace the count in the line after it had been increased by 1.

The first set of numbers u see is the epoch time of the time that line is created.

I was thinking of running something like

Code:

LC = line Count of file
While ( LC > 1)
      do
       Read  line
           Var1= Epochtime, Var2 = CountValue,
           If [ (CurrentSystemTime - Var1 ) >= 900 ]
                   Var2 = Var2 ++
                   Insert Var2 back into the line replacing the old value
             LC = LC --
           else
             LC = LC --
      done
LC = Line Count of file
While ( LC > 1)
       do
        Read Line
           Var2 = Count value
           If [ mod(var2/5) == 0 ]
               Send line to another file or send email alert to abc.def@xxx.com containg the To and From addess
               LC = LC --
           Else
               LC = LC --
        done

This is a rough idea of how i imagine the logic to be . The pboblem I face is how to extract the values to a variable and how to insert back to the respective line and continue on for each line of the file. This is primitive any optimizing will be helpful.

Epoch time is the representation of time in seconds by the linux system.