Contributor: SWAG SUPPORT TEAM 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.