(PHP 4, PHP 5, PHP 7)
Strip whitespace (or other characters) from the end of a string
string rtrim ( string $str [, string $character_mask ] )
This function returns a string with whitespace stripped from the end of str.
Without the second parameter, rtrim() will strip these characters:
" " (ASCII 32 (0x20)), an ordinary space. "\t" (ASCII 9 (0x09)), a tab. "\n" (ASCII 10 (0x0A)), a new line (line feed). "\r"