End-of-Line Trim

When editing text files often times one ends up putting extra spaces and tabs at the end of each line.
Develop a simple algorithm to remove these extra characters.
It shall take an input string and produce a right-trimmed output string.


Input Output
"abc" "abc"
"abc " "abc"
"abc\t" "abc"
" abc" " abc" (does not remove beginning whitespace)
"ab\r\n cd \r\n" "ab\r\ncd\r\n" (removes whitespace at end of second line)
"\r\n" "\r\n"


Be sure to handle both Windows \r\n and Unix line endings \n