Shell Programming and Scripting

N=`wc -l /home/count.txt | awk '{print $1}'`

while test "$N" -gt "10"
do
sed -i "1,1 d" /home/count.txt
done

N=`wc -l /home/count.txt | awk '{print $1}'`

while test "$N" -gt "10"
do
    echo "something"
    ((  n-- ))
done

N=`wc -l /home/count.txt | awk '{print $1}'`
[ $N -gt 10 ] && sed "1,$((N-10))d" /home/count.txt

tail -10 /home/count.txt > /tmp/trim.$$
mv /tmp/trim.$$ /home/count.txt

typeset -i N  ## define N as an integer (strips out the leading whitespace from wc)
N=`wc -l < /home/count.txt`

while test $(wc -l < /home/count.txt) -gt 10
do
        sed -i "1,1 d" /home/count.txt
done

while [ $(wc -l < /home/count.txt) -gt 10 ]
do
        sed -i "1,1 d" /home/count.txt
done

sed -i "1,$(( $(wc -l <file) - 10 ))d" file