$twiddle(<tilde-expansion>)

This function is used to do tilde-expansion on the given name. The tilde is required. If a user exists on the system with a home directory, the full path of that directory is returned. If the user does not exist, nothing is returned. If a tilde is not the first character, the input is returned.

This is useful for ensuring that files will be written to your home directory, regardless of the current directory.

full path of home directory if user exists, nothing if not, input if error

$twiddle(~)                  returns your home directory
$twiddle(~jvs)               returns home directory for user jvs
$twiddle(~nosuchuser)        no such user, returns nothing
$twiddle(blah)               bad input, returns "blah"