Shell Programming and Scripting

awk -F"_" -v d=$(date "+%d%m%Y") '
$3==d && $5>n[$3$4] {n[$3$4]=$5;a[$3$4]=$0}
END{for(i in a){print a[i]}}' file | sort

#!/usr/bin/ksh
pseq=""
pver=""
phub=""
pfed=""
pdat=""
cat a.txt | grep `date  '+_%d%m%Y_'` | sort -t'_' +2 +3 +4 > out.txt
while IFS="_" read hub feed tdate seq ver ; do
  if [[ "$seq" != "$pseq" ]]
  then
     if [[ "$pseq" == "" ]]
     then
        pseq=$seq
        pver=$ver
        phub=$hub
        pdat=$tdate
        pfed=$feed
     else
        echo "${hub}_${feed}_${tdate}_${pseq}_${pver}"
        pseq=$seq
        pver=$ver
        phub=$hub
        pdat=$tdate
        pfed=$feed
     fi
  else
    if [[ "$pver" < "$ver" ]]
    then
      pver=$ver
    fi
  fi
done < out.txt > out
echo "${phub}_${pfed}_${pdat}_${pseq}_${pver}" >> out
rm -f out.txt

#!/bin/ksh
d=`date +"%d%m%Y"`
sort -t"_" -r -k345 infile | while read line
do
v1=`echo $line | cut -d"_" -f1`
v2=`echo $line | cut -d"_" -f2`
v3=`echo $line | cut -d"_" -f3`
v4=`echo $line | cut -d"_" -f4`
v5=`echo $line | cut -d"_" -f5 | cut -d"." -f1`
if [[ $d -eq $v3 ]];
then
 if [[ $v4 -ne $prv4 ]];
 then
 print $v1"_"$v2"_"$v3"_"$v4"_"$v5".pgp"
 fi
prv4=$v4
fi
done