:bread crumbs: /n./ Debugging statements inserted into a program that emit output or log indicators of the program's {state} to a file so you can see where it dies or pin down the cause of surprising behavior. The term is probably a reference to the Hansel and Gretel story from the Brothers Grimm; in several variants, a character leaves a trail of bread crumbs so as not to get lost in the woods.
:break: 1. /vt./ To cause to be {broken} (in any sense).
"Your latest patch to the editor broke the paragraph commands."
2. /v./ (of a program) To stop temporarily, so that it may
debugged.
The place where it stops is a `breakpoint'. 3. [techspeak]
/vi./ To send an RS-232 break (two character widths of line high)
over a serial comm line. 4. [Unix] /vi./ To strike whatever key
currently causes the tty driver to send SIGINT to the current
process. Normally, break (sense 3), delete or {control-C} does
this. 5. `break break' may be said to interrupt a conversation
(this is an example of verb doubling). This usage comes from radio
communications, which in turn probably came from landline
telegraph/teleprinter usage, as badly abused in the Citizen's Band
craze a few years ago.
:break-even point: /n./ In the process of implementing a new computer language, the point at which the language is sufficiently effective that one can implement the language in itself. That is, for a new language called, hypothetically, FOOGOL, one has reached break-even when one can write a demonstration compiler for FOOGOL in FOOGOL, discard the original implementation language, and thereafter use working versions of FOOGOL to develop newer ones. This is an important milestone; see {MFTL}.
Since this entry was first written, several correspondents have reported that there actually was a compiler for a tiny Algol-like language called Foogol floating around on various {VAXen} in the early and mid-1980s. A FOOGOL implementation is available at the Retrocomputing Museum http://www.ccil.org/retro.
:breath-of-life packet: /n./ [XEROX PARC] An Ethernet packet that contains bootstrap (see {boot}) code, periodically sent out from a working computer to infuse the `breath of life' into any computer on the network that has happened to crash. Machines depending on such packets have sufficient hardware or firmware code to wait for (or request) such a packet during the reboot process. See also {dickless workstation}.
The notional `kiss-of-death packet', with a function complementary to that of a breath-of-life packet, is recommended for dealing with hosts that consume too many network resources. Though `kiss-of-death packet' is usually used in jest, there is at least one documented instance of an Internet subnet with limited address-table slots in a gateway machine in which such packets were routinely used to compete for slots, rather like Christmas shoppers competing for scarce parking spaces.
:breedle: /n./ See {feep}.
:bring X to its knees: /v./ To present a machine, operating system, piece of software, or algorithm with a load so extreme or {pathological} that it grinds to a halt. "To bring a MicroVAX to its knees, try twenty users running {vi} — or four running {EMACS}." Compare {hog}.
:brittle: /adj./ Said of software that is functional but easily broken by changes in operating environment or configuration, or by any minor tweak to the software itself. Also, any system that responds inappropriately and disastrously to abnormal but expected external stimuli; e.g., a file system that is usually totally scrambled by a power failure is said to be brittle. This term is often used to describe the results of a research effort that were never intended to be robust, but it can be applied to commercially developed software, which displays the quality far more often than it ought to. Oppose {robust}.
:broadcast storm: /n./ An incorrect packet broadcast on a network that causes most hosts to respond all at once, typically with wrong answers that start the process over again. See {network meltdown}; compare {mail storm}.