22 lines
1.3 KiB
Plaintext
22 lines
1.3 KiB
Plaintext
shell
|
|
|
|
n. [orig. Multics techspeak, widely propagated via Unix] 1. [techspeak] The
|
|
command interpreter used to pass commands to an operating system; so called
|
|
because it is the part of the operating system that interfaces with the
|
|
outside world. 2. More generally, any interface program that mediates access
|
|
to a special resource or server for convenience, efficiency, or security
|
|
reasons; for this meaning, the usage is usually a shell around whatever.
|
|
This sort of program is also called a wrapper. 3. A skeleton program,
|
|
created by hand or by another program (like, say, a parser generator), which
|
|
provides the necessary incantation s to set up some task and the control
|
|
flow to drive it (the term driver is sometimes used synonymously). The user
|
|
is meant to fill in whatever code is needed to get real work done. This
|
|
usage is common in the AI and Microsoft Windows worlds, and confuses Unix
|
|
hackers. Historical note: Apparently, the original Multics shell (sense 1)
|
|
was so called because it was a shell (sense 3); it ran user programs not by
|
|
starting up separate processes, but by dynamically linking the programs into
|
|
its own code, calling them as subroutines, and then dynamically de-linking
|
|
them on return. The VMS command interpreter still does something very like
|
|
this.
|
|
|