The bane of many a computer user. Some programs are sensitive to whitespace. Normally inconvenient, but sometimes a catastrophe. Like when you inadvertantly leave whitespace at the end of a line. Unless you set up some special editing modes, this whitespace is invisible, yet your file won't work.

An example of a horrible place for trailing whitespace is the end of a Perl here document. If you have something like this:

$x = <<END;
This is the first line
This is the second
END  
(highlight the "END" line to see what's going on!), Perl won't recognise the terminator!

This can waste a significant amount of time out of your life.

Log in or registerto write something here or to contact authors.