B
background job
See background process
background process
A job that runs without interfering with normal command-line entries. A process
runs in the background when the command to begin the process is issued with
an ampersand (&) character following it. For example, to run the calculator
program in background, a user would issue the command dxcalc &. As a result,
the calculator would be invoked in one window, while the command line on which
the dxcalc command was issued would be ready to accept new commands.
See also foreground process
Berkeley Internet Name Domain
See BIND (Berkeley Internet Name Domain)
Berkeley Software Distribution
See BSD (Berkeley Software Distribution)
Berkeley UNIX
See BSD (Berkeley Software Distribution)
/bin directory
A directory that contains executable programs and scripts. For example, the
/usr/bin directory contains programs that nonprivileged users can run, and the
/sbin directory contains programs that only privileged users can run.
See also binary file, path, script
binary
1. Referring to the number 2 or the system of binary numeration.
2. Referring to an executable file created by a compilation process.
3. Referring to a situation that can assume one of two possible states.
binary file
A file created by a compilation process. Binary files contain codes that are not
part of the ASCII character set and utilize all 256 possible byte values.
binary operator
1. A symbol that represents an operation to be performed on two arrays, data
items, or expressions. The four types of binary operators are character, logical,
numeric, and relational.
2. An arithmetic operator that has two terms.
BIND (Berkeley Internet Name Domain)
A name service available on internet networks.
bit bucket
A term for any receptacle into which data is placed without the possibility of
retrieval. It is often used to refer to the null device /dev/null.
block device
A data storage or transfer device that manipulates data in groups of a fixed size;
for example, a disk, whose data storage size is usually 512 bytes.
See also character device
block device switch table
The method used by the DIGITAL UNIX operating system to select the entry
points associated with a particular block device.
See also character device switch table
blocking mode
See synchronous execution
block special file
A device special file that provides access to an input or output device and is
capable of supporting a file system.
See also device special file
BOM
A sequence of characters written on a magnetic tape to signify the beginning of
medium.
See also EOF (end of file), file mark
Boolean
1. An algebra (named for George Boole) that is similar in form to ordinary
algebra, but in which the values of the variables are restricted to the two possible
values true and false. The logic of Boolean algebra works well with the binary
logic of computers, where values are represented by the digits 0 and 1.
2. A term sometimes used to refer to Boolean operators, including AND, OR, NOT,
EXCEPT, IF, THEN, TRUE, and FALSE.
Bourne shell
The command interpreter and interpreted programming language originally
developed by Steve Bourne.
See also shell
breakpoint
A place in a source code program that stops the debugger during program
execution. Breakpoints aid in the testing and debugging of programs.
See also tracepoint
break statement
In a programming language, a statement that causes the program to exit
immediately from the current control structure (such as a case statement or a for
loop). A break statement is often used to terminate execution of a loop before the
programmed number of iterations has been performed.
BSD (Berkeley Software Distribution)
The UNIX software release of the Computer System Research Group of the
University of California at Berkeley -- the basis for some features of the DIGITAL
UNIX version of the UNIX system.
BSD socket interface
A transport-layer interface provided for applications to perform interprocess
communication between two unrelated processes on a single system or on
multiple connected systems. This interprocess communications facility allows
programs to use sockets for communications between other programs, protocols,
and devices.
built-in
A command that is built into a shell, as opposed to a command that stands alone
as a separate executable file and is invoked by a shell.
