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Old 09-18-2011, 01:21 PM   #1
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Registered: Oct 2009
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no of days between two dates in yyyymmdd format

Hi All,

I have a file which has 3 column, column 2nd and 3rd have date in yyyymmdd format.

i have to find find the no. of days between two dates.

ex: file
column1 column2 column3
A 20090909 20100908
A 20080102 20090107
B 20110909 20110910
A 20001010 20030405

so i have to find out no of days when "A" was present.
this input "A" is command line argument, it can be "B" too..

-Thanks in advance
Old 09-18-2011, 03:15 PM   #2
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If I understand your question correctly, you want to calculate the difference between dates, in days, for records that match a specified argument. If so, this should be close:
#! /bin/bash
#      run as: A    # (use record type as desired)
#      -  uses embedded data file name; customize as necessary
while read rec; do 
    #  Split each record into separate fields
    rectype=$(echo $rec | cut -d' ' -f1);
    d1=$(echo $rec | cut -d' ' -f2);
    d2=$(echo $rec | cut -d' ' -f3);
    #   If record type matches that specified on commandline...
    if [ "$rectype" = "$1" ]; then 
        #   normalize dates to seconds-since-epoch
        date1=$(date -d "$d1" "+%s" ); 
        date2=$(date -d "$d2" "+%s" );
        #  Calculate difference in seconds, convert back to days, and report
        days=$(( ($date2-$date1)/86400 )); 
        echo $days;
#  Read from data file
done < LQcsegau.dat
--- rod.

Last edited by theNbomr; 09-18-2011 at 03:36 PM.


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