And as a side-note, something I learned the other day for error handling in system calls :

system("/usr/bin/scp $file $username\@$host:$remoteFile");
die "System call to scp command failed! : $!\n" if ($? != 0);
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The special variable $? returns a boolean value for success or fail on system calls. So the above snippet performs a reliable "or die" check on your command. A handy one to know, especially as system tends to be a little unreliable in terms of error checking / return values when using a straight die, IMHO.

Update: as per comments below, not a "boolean" in the strict sense of the word. Call it an "azatoth boolean" :)

Azatoth a.k.a Captain Whiplash