Glossary
107365 Tandem Computers Incorporated
Glossary–3
enclosure
. A unit composed of one or more labels, such as |THEN| or |DO|, and the
text associated with each label. Enclosures are found only in the TACL built-in
functions #DEF, #IF, #CASE, and #LOOP, which are enclosed in brackets to provide
boundaries for their enclosures. TACL defers execution of text that is associated with
labels until it determines the correct label to use.
Enscribe.
A database record management system.
exception
. An unusual event that causes TACL to interrupt the normal flow of
invocations and transfer to special code (see exception handler). This unusual event
could be BREAK, a TACL error, or a user-defined exception.
exception handler
. A series of TACL statements that perform resource deallocation and
cleanup after an exception.
exclusion mode.
The attribute of a lock that determines whether any process except the
lock holder can access the locked data.
expand
. A type of invocation (see invoke). To expand a variable, specify the variable
name in brackets; TACL returns the expansion in place of the variable name.
expression.
A text, string, or integer constant, a variable, or a value obtained by
combining constants, variables, and other expressions with operators. Expressions are
used as arguments to commands and built-in functions.
extended data segment.
One or more consecutive absolute segments that are
dynamically allocated by a process.
extensible data segment.
An extended data segment for which swap file extents are not
allocated until needed.
extent.
A contiguous area of a disk allocated to the same file.
fault tolerance.
The ability of a computer system to continue operating during and after
a fault (the failure of a system component).
file code.
An integer value assigned to a file for application-dependent purposes.
file lock.
A mechanism that restricts access to a file by all processes except the lock
owner.
file
. As used here, a file refers to an organized collection of data stored on a disk. In
general, a file on a Tandem system can be a disk file, a process, or a device.
file name.
A unique name for a file. This name is used to open a file and thereby
provides a connection between the opening process and the file. File names consist of
one to eight alphanumeric characters, the first of which must be alphabetic.
file name template.
A sequence of characters including the asterisk (*) and question
mark (?) that matches existing file names by expanding each asterisk to zero or more
letters, digits, dollar signs ($), and pound signs (#) and replacing each question mark
with exactly one letter, digit, dollar sign, or pound sign.