unset - Delete variables
unset name ?name name ...?
This command removes one or more variables.
Each name is a variable name, specified in any of the
ways acceptable to the set command.
If a name refers to an element of an array then that
element is removed without affecting the rest of the array.
If a name consists of an array name with no parenthesized
index, then the entire array is deleted.
The unset command returns an empty string as result.
An error occurs if any of the variables doesn't exist, and any variables
after the non-existent one are not deleted.
Copyright © 1993 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.