Chain
1. <operating system> (From
BASIC's "CHAIN" statement) To pass control to a child or successor without going through the
operating system command interpreter that invoked you. The state of the parent program is lost and there is no returning to it.
Though this facility used to be common on memory-limited microcomputers and is still widely supported for
backward compatibility, the jargon usage is semi-obsolescent; in particular,
Unix calls this
exec.
Compare with the more modern "subshell".
2. <programming> A series of linked data areas within an
operating system or
application program.
"Chain rattling" is the process of repeatedly running through the linked data areas searching for one which is of interest.
The implication is that there are many links in the chain.
3. <theory> A possibly infinite, non-decreasing sequence of elements of some
total ordering, S
x0 <= x1 <= x2 ...
A chain satisfies:
for all x,y in S, x <= y \/ y <= x.
I.e. any two elements of a chain are related.
("<=" is written in
LaTeX as
\sqsubseteq).
[
Jargon File]
