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.