UNIX for Dummies Questions & Answers

Hi Friends
I have a long file having fields in the form :
Field1 yy/mm/dd hh:mm:ss Duration(Sec)
line 1) 123123 05/11/30 12:12:56 145
line 2) 145235 05/11/30 12:15:15 30
line 3) 145264 05/11/30 13:14:56 178
.
.
I want to subtract yy/dd/dd hh:mm:ss in line (2) from yy/mm/dd hh:mm:ss in line (1) and compare the result(in seconds) with the duration(sec) of line(1).
and echo a message whether it is < or >. I want to apply this to the long file This can be done easily in excel as we usually drag a formula in excel. But in unix how I don't know.
Please Dont refer me to Datecalc as I want specific script to do so.
Thanks In advance.

Here is a starting point for you.

Have converted your line (123123 05/11/30 12:12:56 145) into time since epoch.

Code:

#! /bin/sh

while read line
do
DATE=$(echo $line | awk '{ print $2 }')
TIME=$(echo $line | awk '{ print $3 }')
echo $(date -d "$DATE $TIME" +%s)

done < vanand.txt

vanand.txt contains

123123 05/11/30 12:12:56 145
145235 05/11/30 12:15:15 30
145264 05/11/30 13:14:56 178
.
.

After this, I think you need to store the values in an array and then do the comparison.

Cheers,
vino