On systems which follow Unix shell conventions, a user may
supply a pathname with the tilde (~) character to refer to
the user's home directory (e.g., ~/file), or another
user's home directory (e.g., ~user/file). This works
in many Unix shells, but often does not work in scripts or
applications by default. If your script would like to
support this convenient but optional notation, then the
built-in getpwnam() function and %ENV hash
are the best places to refer, or use the newer globbing
features that support them automatically.