.z.pc:f

Where f is a unary function, .z.pc is called after a connection has been closed.

As the connection has been closed by the time f is called there are strictly no remote values that can be put into .z.a, .z.u or .z.w – so the local values are returned.

To allow you to clean up things like tables of users keyed by handle, the handle that was being used is passed as a parameter to .z.pc

KDB+ 2.3 2007.03.27 Copyright (C) 1993-2007 Kx Systems
l64/ 8cpu 16026MB simon ...

q).z.pc
'.z.pc
q).z.pc:{0N!(.z.a;.z.u;.z.w;x);x}
q)\p 2021
q)(2130706433;`simon;0;4)

q).z.a
2130706433
q).z.u
`simon
q).z.w
0
q)