Remove Blank lines from file

sed '/./!d' backupfilelist.txt > temp1.txt

sed '/^$/d' backupfilelist.txt > temp1.txt

grep -v '^   

filename.txt > temp1.txt

Tech 1 :   sed '/./!d' filename.txt > temp1.txt

Tech 2 :  sed '/^$/d' filename.txt > temp1.txt

Tech 3 :  grep -v '^$' filename.txt > temp1.txt