1Preface
1.1 Brief product description
In most cases, the solving of commercial problems involves processing large amounts of data. COBOL is particularly well suited to this task. COBOL programs are largely independent of the particular features of individual hardware systems. The language is laid down clearly and precisely in an official document issued by the American National Standards Institute (ANSI) under the title "American National Standard for Information Systems - Programming Language COBOL - ANSI X3.23-1985" and Addendum "ANSI X3.23a-1989, Intrinsic Function Module". This is a revised version of the 1974 standard. The internal standard functions supported as of V2.1A of the compiler are described in the above Addendum. The German standard version DIN 66028-1986 and the international standard version ISO 1989:1985 correspond to the American National Standard. The Intrinsic Functions by ANSI correspond to the international norm "ISO/IEC 1989 Amendment 1, Intrinsic Function Module". For the purpose of description, the ANSI publication divides COBOL into a nucleus and eleven functional modules, of which five are optional (Report Writer, Communication, Debug, Segmentation, Intrinsic Functions). Each of these modules in turn contains one or two functional levels. The lower level of a module is a true subset of the higher level of the same module. Since December 2002, the international standard ISO 1989:2002 has been valid for COBOL. This standard is similar to the ISO 1989:1985 standard except that it does not contain the previous subdivision into modules, and, on the other hand, Amendment 1, “Intrinsic Function Module“, and numerous new language elements have been added. It is to be published as a DIN standard shortly.
U41112-J-Z125-3-76 1 Target group and summary of contents Preface
The COBOL2000 (BS2000) compiler supports the high ANS85 COBOL language set. The optional Report Writer and Segmentation language modules are also supported in accor- dance with the high level of ANS85. In addition, the COBOL2000 (BS2000) compiler offers a large subset of the language functionality from the ISO 1989:2002 standard, which is now valid. The optional Communication and Debug language modules, which have been dropped from the new standard, are not supported. In BS2000, these modules are replaced by the products UTM and AID, respectively.
1.2 Target group and summary of contents
The present manual is aimed at programmers and training personnel. It is intended as a guide to the writing and maintenance of COBOL programs and as a complement to training manuals. It is neither a COBOL textbook nor a user guide. Readers are assumed to have a sound general knowledge of programming and some basic knowledge of COBOL. The operation of the compiler and the creation of an executable COBOL program are described in the "COBOL2000 User Guide" [1]. The manual includes all language elements which may be used when creating COBOL programs, organized according to function, format, syntax rules, general rules, and examples: The function section offers a concise, general description of the individual language elements. If several formats are involved, the functional differences between them are explained in brief. The format section defines the specific arrangement of character strings and separators required for a valid clause, statement, or compound structure. The occurrence of specific strings and separators and their order of appearance as shown in the format section are decisive. The specific notation used for describing the formats is explained under the heading "General format". Where more than one specific arrangement is permitted, the various formats are desig- nated as "Format 1, Format 2 etc.". The syntax rules section describes the particular requirements and restrictions for a given function and offers additional explanations and application guidelines.
2 U41112-J-Z125-3-76 Preface Target group and summary of contents
General rules describe the use of the language structure within the program context; that is, as a function of previous and subsequent as well as superior and subordinate structures and in conjunction with references and cross-references from other language elements which, strictly speaking, are independent of the described structure. Restrictions on the order of effects at program runtime are discussed. Generally speaking, all these consider- ations are concerned with those elements which do not appear directly in the format section. Under Example you will find a concrete example of the language element that has just been described. The structure is analogous to that used for the standard COBOL document. Certain language elements are qualified by a colors*, as follows:
Bluish green print Fujitsu Siemens COBOL2000 compiler extensions to the 1985 COBOL language standard. These include: – implementor-defined extensions – extensions from the Journal of Development (JOD) – extensions from the X/OPEN Portability Guide – extensions rom the 2002 COBOL standard Orange print Language elements to be avoided in new programs, since they will not be supported by future COBOL standards (obsolete elements). It is advisable to remove them from old programs.
The "Contents" table gives an overview of the general structure and organization of the manual. The "Index" enables rapid access to desired information. The most important terms and concepts used in this manual are defined in alphabetical order in the "Glossary". Other manuals are referred to in the text by their abbreviated titles. The full title of each publication mentioned is given at the back of the manual under "Related publications". The "Glossary" and "Index" sections have been excluded from the color qualification system.
* The colors were chosen so as to ensure that readers who suffer from color-blindness will nevertheless be able to distinguish the colored print from normal black print.
U41112-J-Z125-3-76 3 Changes compared to the predecessor version Preface
1.3 Changes compared to the predecessor version