Clipper: Difference between revisions
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'''Clipper''' is 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. 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. | 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 | 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 80s become a de-facto standard for development of custom business software solutions on PCs, 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. | 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. | ||
==== | ==Versions== | ||
from Nantucket Corporation | |||
* Winter'84 (May 1985) | |||
* Summer'85 (1985) | |||
* | * Winter'85 (Jan 1986) | ||
* Autumn '86 (Oct 1986) | |||
* | * Summer '87 (Jan 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. | ||
* 5.0 (1990) brings with it rudimentary object-oriented extensions to the xBase language. | |||
**5.01 (Apr 1991) | |||
== | ==Add-on products, libraries and compatible products== | ||
* | * Clip-4-Win - A library that allows you to create 16 bit Win-OS/2 or Windows 3.x applications. | ||
* | * DOC - Code documentation generator | ||
* FiveOS2 - GUI library for CA-Clipper | |||
* | * [[SNAP!]] - Code documentation generator - Originally in the [[public domain]], later versions shareware. | ||
== | ==Text editor 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 separate download. | ||
[[Category:xBase]] | |||
Latest revision as of 17:36, 2 November 2023
Clipper is 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 80s become a de-facto standard for development of custom business software solutions on PCs, 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.
Versions
from Nantucket Corporation
- Winter'84 (May 1985)
- Summer'85 (1985)
- Winter'85 (Jan 1986)
- Autumn '86 (Oct 1986)
- Summer '87 (Jan 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.
- 5.0 (1990) brings with it rudimentary object-oriented extensions to the xBase language.
- 5.01 (Apr 1991)
Add-on products, libraries and compatible products
- Clip-4-Win - A library that allows you to create 16 bit Win-OS/2 or Windows 3.x applications.
- DOC - Code documentation generator
- FiveOS2 - GUI library for CA-Clipper
- SNAP! - Code documentation generator - Originally in the public domain, later versions shareware.