chain

n 1: a series of things depending on each other as if linked

together: "the chain of command"; "a complicated

concatenation of circumstances" [syn: {concatenation}]

2: a series of linked atoms (generally in an organic molecule)

[syn: {chemical chain}]

3: a series of (usually metal) rings or links fitted into one

another to make a flexible ligament

4: a number of similar establishments (stores or restaurants or

banks or hotels or theaters) under one ownership

5: anything that acts as a restraint

6: a unit of length

7: a series of hills or mountains; "the valley was between two

ranges of hills"; "the plains lay just beyond the mountain

range" [syn: {range}, {mountain range}, {range of

mountains}, {mountain chain}, {chain of mountains}]

8: metal shackles; for hands or legs [syn: {iron}, {irons}, {chains}]

9: a necklace made by a stringing objects together; "a string

of beads" or "a strand of pearls" [syn: {string}, {strand}]

v : fasten or secure with chains; "Chain the chairs together"

[ant: {unchain}]

chain

1. (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. 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. 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}]

(1995-02-03)