Shell Programming and Scripting

#!/bin/ksh

INPUT_FILE1=$1
INPUT_FILE2=$2
OUTPUT_FILE=$3

exec 4< $INPUT_FILE1
exec 5< $INPUT_FILE2
exec 6> $OUTPUT_FILE

    
for LINE in 1 2 3 4
do
    read -u4 CURRENT_LINE_IN_FILE1
    read -u5 CURRENT_LINE_IN_FILE2
    
    for COLUMN in 1 2 3
    do
        TOKEN1=$(echo $CURRENT_LINE_IN_FILE1 | cut -d '|' -f $COLUMN)
        TOKEN2=$(echo $CURRENT_LINE_IN_FILE2 | cut -d '|' -f $COLUMN)
        
        if (( (($LINE == 1) && ($COLUMN == 3)) ||
              (($LINE == 2) && ($COLUMN == 2)) ||
              (($LINE == 4) && (($COLUMN == 2) || ($COLUMN == 3))) ))
        then
            if [[ $TOKEN1 != $TOKEN2 ]]
            then
                print -u6 "Mismatch found in (line , column) = "\
                "($LINE , $COLUMN), in file: $INPUT_FILE1 found "\
                "$TOKEN1 but in file: $INPUT_FILE2 found $TOKEN2"
            fi
        fi
    done
done

4<&-
5<&-
6<&-