Drive

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The Drive BRConfig.sys specification is a drive letter followed by a colon. The drive parameter may specify locations on your hard drive, certain special devices such as a printer or modem.

The first Drive specification defines the default directory when Business Rules! is started.

Comments and Examples

Business Rules! utilizes a DOS-like naming structure for all file and path references. The Drive specification allows Unix or Linux files to be accessed with DOS naming conventions.

Windows uses case insensitive filenames, whereas all Unix derivatives (Linux and Mac use case sensitive filenames. Therefore, the second parameter of the drive statement is case sensitive for Linux and Mac, but not for Windows. All other drive statements are case insensitive.

The Windows model permits accessing drives without drive statements, but the Status command does not report the configuration of such drives. Therefore you are encouraged to get familiar with the drive statement, and begin using it.

BRConfig.sys statement pathnames are subject to preceding drive definitions. To use actual pathnames, begin the names with a colon.

Syntax

DRIVE <drive letter>, /<subdirectory path> [\<directory name>]

Drive.png

Parameters

"Drive-letter" is the letter to be assigned and must be followed by a comma.

The "Sub-directory path" must start with the root directory, end with the directory containing Business Rules, and be preceded by a forward slash. This parameter is case-sensitive; Business Rules will not translate uppercase specifications into lowercase letters.

"Directory name" is optional and specifies a directory beneath the directory containing Business Rules. The specified name becomes the current directory and must be preceded by a forward slash. This parameter is case-sensitive; Business Rules will not translate uppercase specifications into lowercase letters.

Start-up Default

At least one drive specification is required in the BRConfig.sys file for Unix/Linux/Windows/Mac versions of Business Rules! prior to release 4.18.

Technical Considerations

  1. The only place that drive can be specified is in the BRConfig.sys file; it is not valid with the config command.
  2. There must be at least one drive statement as it was in Unix which makes it clear where the initial working directory is. In version 3.8 drive statements were required only for file sharing.
  3. Drive statements must now have four parameters. This avoids any confusion about whether or not a drive statement with three parameters was intended under 3.9 or whether it was left over from prior versions of BR. A backslash in the fourth parameter may be used to startup in the directory specified by the second parameter.

Drive Definition

The drive definition has the following format:

DRIVE drive-id[:],actual-drive-path,\current-dir-path

"Drive-id" is the drive letter (A-Z) appearing in the BR program OPEN string filename (e.g. C:).

"Actual-drive-path" is the actual full pathname to the node referenced by the drive-id. (e.g E:\CUSTFILES or \\MYSERVER\CUST_SHARENAME\) Note that UNC names (beginning with \\server-name) operate significantly faster than Drive letter mappings.

"Current-dir" is the parameter of an implied beginning CD command on the drive. BR acts as though your application changed to this subdirectory during startup.

For example:

DRIVE C:,F:\MYAPP,SERVER-2,\PRL

Defines a network node (F:\\MYAPP) as the C: drive and performs an implied CD \PRL on this drive during startup.

BR assumes that any references to undefined drives (F:, G:, etc.) refer to the root directory on those drives. Also, RECORD LOCKING IS NOT PERFORMED on such drives. The Protect Reserve command only works on filenames that pertain to drives that are identified by a drive statement.

Summary of the BR file search order

BR32.EXE Windows Working Directory or UNIX current directory. Note that this may be different from the actual location of BR if a full pathname is given as the executable. This is regarded as the BR executable directory.
BRConfig.sys Command Line Parameter or BR executable directory
WBCmd.wbh First Drive location
BRServer.dat BRServer configuration statement or first Drive location
BRSerial.dat BR executable directory
WBTerm.out BR executable directory
Initial 'current' directory First Drive location

Note that pathnames given in BRConfig.sys statements are subject to preceding DRIVE statements. To use actual pathnames, begin the names with a colon.