Code 
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#!/bin/ksh
RRSRC=/test
RREP=/test
#Directories
test_dir=/test
#Imp Files
FILENAME=/test/files.txt
# rename the datasets to test1 and test2 ----Is there a better method to rename at RENAME STEP
llll=test1.sas7bdat
mmmm=test2.sas7bdat
set +x
# Sas prg to be executed
pgm_name=from_tytt
rpt_pgm_name=ppppp
export log=$RLOG/${seq_nbr}_${pgm_name}_${year}${emth}.log
export log1=$RLOG/${seq_nbr}_${rpt_pgm_name}_${year}${emth}.log
#
#  read in the ending month as they are used to process the files for that
#  Quarter.
#
touch ${log}
touch ${log1}
echo ${pgm_name}
echo ${rpt_pgm_name}
log_date=`date +%m%d%y`
echo ${log_date}
echo "Starting SAS"
#Variable for 2 digit month calculation
a=0
# Create the directory with the eod date this directory will be purged at the completion of the process
eod=`date +%m%d%y`
echo $eod
export eod
archive_dir=/test/"$eod"
mkdir $archive_dir
#Read the files for the quarterie if it for the quarter =1 then  read files for jan feb march
# the files start with 
#'a_d_c'
#'kpp_s' 
#'ax_P_Tl_Gr' 
#'T_P_al_Gd_At' 
#'x_P_Rd'
#'a_P_l_ot_Ng' 
# The FILENAME contains these strings and is used to read only these files 
# the files are in the string_yyyymmdd_hhmmss.txt format so calculate the mth variable
# to get a two digit number
while IFS= read -r LINE
do
Mth=9
COUNT=1
while [ $COUNT -lt 4 ];
do
  if [ $Mth -lt 10 ];  then
     Mth="$a$Mth"
  fi
#  Copy the files tothe temporary archive directory
   cp "$test_dir/$LINE"_"$YEAR$Mth"*.txt $archive_dir/.
  Mth=`expr $Mth - 1`
  COUNT=`expr $COUNT + 1`
done
done < "$FILENAME"
# From the list of files for the quarter
# read each file and create dataset.
# Since each file has different variable so 
# pass the number of variables dynamically
# to the Sas prg.Export the file name(obj) and the number of variable parameter(var2)
ls -1 "$archive_dir|while read obj
  do
    LINE=`basename $obj .txt`
    echo $LINE
    export LINE
    echo "Inside DO $LINE loop"
    export obj
    echo  $obj
if [ `nawk -v a="$obj" -v b="a_d_c" 'BEGIN{print match(a,b)}'` -ne 0 ];then var2=var25
   elif [ `nawk -v a="$obj" -v b="kpp_s" 'BEGIN{print match(a,b)}'` -ne 0 ];then var2=var11
            elif [ `nawk -v a="$obj" -v b="ax_P_Tl_Gr" 'BEGIN{print match(a,b)}'` -ne 0 ];then var2=var7
                 elif [ `nawk -v a="$obj" -v b="T_P_al_Gd_At" 'BEGIN{print match(a,b)}'` -ne 0 ];then var2=var7
                     elif [ `nawk -v a="$obj" -v b="x_P_Rd" 'BEGIN{print match(a,b)}'` -ne 0  ];then var2=var17
                         elif [ `nawk -v a="$obj" -v b="a_P_l_ot_Ng" 'BEGIN{print match(a,b)}'` -ne 0  ];then var2=var7
fi
export var2
echo $var2
 
# PROCESS 1 -All files to be processed present in the archive directory
  /sas $RRSRC/$pgm_name.sas -print $RREP/$pgm_name -log $log
  return_code=$?
  if [ $return_code -gt 1 ]
  then
        echo "$pgm_name.sas failed -- return code=$return_code"
        exit $return_code
fi
  done
# For the process we just need to two datasets but we need the latest ones. 
#RENAME STEP
do
  ls -r1 "$archive_dir/a_d_c_????????_??????_??????.????????|sort -t2 +1 -r|head -1|while read obj
  do
    mv $obj $llll
 done
done
do
  ls -r1 "$archive_dir/x_P_Rd_????????_??????_??????.????????|sort -t2 +1 -r|head -1|while read obj
  do
    mv $obj $mmmmm
 done
done
# End of RENAME Step
#  PROCESS 2 read and process further .ONLY THE 
# latest datasets llll=test1.sas7bdat and
#  mmmm=test2.sas7bdat need to processed.

 /sas $RRSRC/$rpt_pgm_name.sas -print $RREP/$rpt_pgm_name -log $log1
return_code=$?
  if [ $return_code -gt 1 ]
  then
        echo "$rpt_pgm_name.sas failed -- return code=$return_code"
        exit $return_code
fi
# purge the archive directory
_purge $archive_dir
_purge()
    {
            # there had better be a directory
            if [ ! -d $1 ]; then
     echo $1: No such directory 1>&2
     return
            fi
    }
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