UNIX for Beginners Questions & Answers

example:
#### here filename contain XXXX_YYYY_ZZZZ_DDD.txt as example
while read filename
#splitting a file without extension
full_filename=$filename
noextension=${full_filename%.*}
extension="${full_filename##*.}"

####assigning a patterns to different variable

echo "$noextension"|awk -F'_' '{ print NF-1 }' > countpattern

##### First fi######
if [ "$countpattern" -eq 5 ] ; then
A=$(echo $noextension|cut -d'_' -f1)
B=$(echo $noextension|cut -d'_' -f2)
C=$(echo $noextension|cut -d'_' -f3)
D=$(echo $noextension|cut -d'_' -f4)
E=$(echo $noextension|cut -d'_' -f5)
fi

####Second If########
if [ ! $extension=txt-a $A=HELP] || [ ! $extension=csv -a ! A =HELP ]
then
UPDATE TABLE ########################
rm full_filename
fi

####third if#####
if [ ! $C = "WE" ]
then
UPDATE TABLE ########################
rm full_filename
fi

while read filename
do
        REMOVE=0

        if [ ! condition1 ]
        then
                REMOVE=1
        fi


        if [ ! condition2 ]
        then
                REMOVE=1
        fi


        if [ ! condition3 ]
        then
                REMOVE=1
        fi

        if [ "$REMOVE" -eq 1 ]
        then
                remove_filename
        fi
done