To delete trailing whitespaces at the end of each lines:
# sed 's/[ \t]*$//' filename > filename_notrailingspace
To remove all blank lines in a given file:
# sed '/^$/d' filename > filename_noblankspace
To remove all leading and trailing whitespaces of each lines in a given file:
$ cat filename | sed 's/^[ \t]*//;s/[ \t]*$//' > filename_nospace
