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- SECTION 20 - Networks
-
- This document contains information that is most often provided
- to users of this section. There is a listing of common
- Technical Information Documents that can be downloaded from the
- libraries, and a listing of the five most frequently asked
- questions and their answers.
-
- TI555 File and record locking in Turbo Pascal
- TI1201 Installing Turbo Pascal on a network
-
- Q. "How do I open a file in read only mode?"
-
- A. Turbo Pascal gives you the ability to open files in several
- different modes. Typically, you will want to change the
- file mode after you call Assign but before you call Reset or
- ReWrite. You make the change by assigning numerical values
- to the built in FileMode variable.
-
- Q. "What is the default value for FileMode? What values are
- associated with a shared Read/Write mode and a shared Read
- only mode."
-
- A. By default, FileMode is set to 2. Set FileMode to 66 to
- acheive a shared Read/Write mode, and set it to 64 to get a
- shared Read only mode.
-
- Q. "How can I implement file and record locking in my own
- code?"
-
- A. Turbo Pascal has no built in functions for file and record
- locking, so you have to go to the assembler level (or
- call MsDos/Intr) to implement this feature. With DOS
- versions 3.0 and later, you can access file and record
- locking via Interrupt $21, Service $5C, SubFunctions 0 and
- 1. (See TI555, and the next Q/A.).
-
- Q. "Beside the method described above, is there a second way to
- access file and record locking routines?"
-
- A. Real world implementations of record and file locking tend
- to be very complex to implement. As a result, it is standard
- practice for programmers to gain access to this kind of
- functionality by purchasing a ready made database toolkit
- such as the Borland Database Engine (release date, summer
- 94), the B Tree Filer from Turbo Power software, or the
- Paradox Engine.
-
- Q. "How can I get access to Netware and other network
- routines?"
-
- A. Turbo Pascal provides no built in access to Netware or
- other network functions other than the calls that are built
- into Windows, such as WNetAddConnection,
- WNetCancelConnection, and WNetGetConnection. In the
- Compuserve library for Section 20 there are (as of May 94)
- various toolkits available, such as the MAPI.ZIP and
- TPAPI.ZIP files.