Editing ADABAS (section)

===The system file===

The system file is an Adabas file reserved for use by Natural, which contains, but is not limited to, the following:
* All Natural programs, both in source format (programs) and in object format (compiled), grouped in libraries;
* File Definition Modules, or Data Definition Modules (DDM), which describe the fields defined within Adabas or other databases supported by Natural as well as userviews, which are fields groupings/subsets;
* Natural error messages;
* The texts of the Help function.

The system file is not limited to Adabas. Natural can also store programs in VSAM on mainframe operating systems. Natural uses the file system on Windows and various Unix implementations.

====Programs====
Natural objects are identified by names up to 8 characters, the first of which must be alphabetical.

The Natural program editor allows source in rows of up to 72 positions.  Lines are numbered by 4 digits. This numbering is generated by Natural during program creation.  Line numbers used by the compiler and editors, and can have important logical functions in the programs.

Comments can be included in two ways:

* Full-line comments are identified by a "*" or "**" prefix.
* Annotated code lines have a "/*" - everything to its right is a comment.

Examples:
 0010 * These two lines (0010 and 0020)
 0020 ** are comments.
 0030 FORMAT LS = 80 /* As well as this part of the line (0030)
 0040 * NOTE: The "/*" form has no space between the SLASH and ASTERISK.
 .
 .
 0200 END
"END" or "." indicates the end of a program.

A Hello World code example:

 * Hello World in NATURAL
 WRITE 'Hello World!'
 END