Clipper

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A dBase II compatible database "compiler" for DOS, originally introduced in 1985 and was one of the host of (mostly) dBase II compatible tools that came to define the term xBase for the family while also being something of a standard on its own, due to extensions it bought to the dBase II language.

Although marketed as one, Clipper is actually not a real compiler as it does not compile to machine code like for instance a C++ or Oberon compiler would, nor to an intermediate language like xBase compilers like X2C and Harbour that compile to C, and then a C compiler is used to compile to machine code. Clipper actually converts source files into tokens and then links them with an interpreter into an executable, the tokenisation is very similar actually to how the REXX interpreter on OS/2 works. Many developers used Clipper for years without realising that it was actually not a compiler and that even though it had limited if any speed advantage over dBase itself. This also meant that it was dead easy to disassemble Clipper executables back into source code, a number of commercial products appeared for just that purpose.

The linker itself was however fairly flexible and allowed the linking of foreign code into the executable, this created an industry around the product that made add-on products in low level languages like C and Modula-2 that were delivered as binaries that you could link into your Clipper programs. As competing products did not offer this flexibility and as the number of add-ons fast became huge, Clipper had by the late 80's become a de-facto standard for development of custom business software solutions on PC's, replacing other database languages and Business Basic products that typically required runtime licenses for delivered products.

Due to the enormous industry support and the high number of add on products available for the product, Clipper was often used in preference to native products when building custom business solutions for OS/2 deployment.

Clipper Virtual Objects

A MS Windows version of Clipper that had extended object-orientation capabilities, unlike the DOS version this was hugely unpopular in the marketplace but was much closer to being a true compiler.

Clipper add-on products, libraries and compatible products

Known Clipper add-on products, libraries and utilities

  • Clip-4-Win - A library that allows you to create 16 bit WinOS/2 or Windows 3.x applications. - Commercial - Current
  • DOC - Code documentation generator - Discontinued.
  • SNAP! - Code documentation generator - Discontinued - Originally in the public domain, later versions shareware.

Text & programmers editors with Clipper support

  • Boxer - Clipper support built in - Commercial - DOS and OS/2 versions discontinued, Win32 version still sold.
  • jEdit - Java based editor - Clipper, Blinker & Classy syntax highlighting available as a seperate download - Current.

Versions

  • Clipper VO v.1.0 - December 1995
  • Clipper 5.3, last version delivered as a DOS product, first version that is able to take advantage of a numeric co-processor and DOS Graphic Modes.
Clipper 5.3a and 5.3b are bug fix releases of 5.3
  • Clipper 5.0 brings with it rudimentary object-oriented extensions to the xBase language
  • Clipper Summer 87 - Delivered in 1988 - Speed and feature improvements especially in the debugger, mostly rewritten in C using Microsoft C. First version to actually ship with a manual but prior to this you were expected to have access to a dBase III manual - By many considered the first well working version of the program - List price USD 695.

Publications & links

Reviews

License

  • Closed source commercial software - Discontinued

Author