How can I translate tildes (~) in a filename?

Use the <> (glob()) operator, documented in the perlfunc manpage. This requires that you have a shell installed that groks tildes, meaning csh or tcsh or (some versions of) ksh, and thus may have portability problems. The Glob::KGlob module (available from CPAN) gives more portable glob functionality.

Within Perl, you may use this directly: 

	$filename =~ s{
	  ^ ~             # find a leading tilde
	  (               # save this in $1
	      [^/]        # a non-slash character
	            *     # repeated 0 or more times (0 means me)
	  )
	}{
	  $1
	      ? (getpwnam($1))[7]
	      : ( $ENV{HOME} || $ENV{LOGDIR} )
	}ex;