help with looping

Shell Programming and Scripting
1 
vesselNames values:
xxx
yyy
zzz

vesselPlanned values:
xxx
zzz
zzz
zzz

OIFS=""
OIFS=$IFS
IFS="\n"

for var in $vesselNames
do
        vesselNameList=`echo $var|cut -d : -f1`
        vesselNameConnectionType=`echo $var|cut -d : -f2`
        vesselNameQuantityList=`echo $var|cut -d : -f3`

if [ "$vesselNameList" != "NA" ]
        then
                if [ "$vesselNameList" = "$vesselPlanned" ]
                then
                result="$file, $carrier, $date, $vesselNameList, $vesselNameConnectionType, $vesselNameQuantityList, $vesselA
utoPlannedName, $name"
                fi
        else
                result="$file, $carrier, $date, $vesselNameList, $vesselNameConnectionType, $vesselNameQuantityList, ZZZZZ, $
vesselAutoPlannedName, $name"
        fi


echo $result
done

it suppose to loop 3 times only, however it shows this instead:

xxx
xxx
xxx
xxx
xxx
zzz
zzz
zzz
zzz
zzz
zzz
zzz
2

It's obvious that you're providing us partial data and a partial script, therefore it's impossible to figure out what's going on, let alone, what's going wrong.

But I'd bet you've got nested loops that are screwed up.

3

As Dave said, only part of coding visible. However, to see 12 outputs is not entirely crazy. You have three vessel_names and four vessel_plans : thus 3 x 4 = 12.
You showed part of how you build the three members of vessel_names, but not the vessel_plans.
If you want to debug this, insert an echo line like:

if [ "$vesselNameList" != "NA" ]
        then
                echo "$vesselNameList" "$vesselPlanned" 
                if [ "$vesselNameList" = "$vesselPlanned" ]