Topic: system-defined variables

topics > computer science > data > Group: variables

builtin functions
running programs in a workspace or environment
temporary data objects


Many programming systems include pre-defined variables such as variables for accessing the current date and time-of-day. System defined variables may control I/O, determine the environment's parameters, set computation parameters, define default values, access page numbers, describe arguments to macros, and define search paths. A working variable, accumulator, or workspace string can be defined for accumulating expression results from operations. The system can define components applicable to all variables, e.g., allocation information and storage type. (cbb 5/80)
Subtopic: environment variables up

Quote: Algol68 includes environment enquiries for determining implementation parameters [»vanwA_1969]

Subtopic: system-defined variables up

Quote: Icon provides system variables for the current state of the scanning function [»grisRE4_1979, OK]
QuoteRef: browPJ10_1967 ;;621 variables for argument count, macro call count, nesting depth.
QuoteRef: gursAF4_1974 ;;131 defines variables with integer a (where:= disc, whichone:=DISCOL) for job control information.
QuoteRef: mashJR_1976 ;;172 "Currently, five variables are assigned special meanings: ... $p permits alteration of the names and order of directory path names used when searching for commands.
QuoteRef: simscrip_1971 ;;14 System attribute routines and variables categorized by extension, e.g., .a for attribute.
QuoteRef: seedH_1971 ;;126 default automatic fields, e.g., Page maintains the current page count.
QuoteRef: seedH_1971 ;;156 level control indicators which turned on when field changes or higher level indicator goes on.
QuoteRef: zakrAD_1969 ;; one implicit register for accumulation results which can be printed, etc. .#@#

Related Topics up

Topic: builtin functions (6 items)
Topic: compiler (18 items)
Topic: running programs in a workspace or environment (14 items)
Topic: temporary data objects
(6 items)

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