how to find number of lines in a file in shell script code example

Example: shell script to count number of lines in a file

echo Enter the filename
read file
w=`cat $file | wc -w`
c=`cat $file | wc -c`
l=`grep -c "." $file`
echo Number of characters in $file is $c
echo Number of words in $file is $w
echo Number of lines in $file is $l