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User-defined symbols

Symbols can be used as alternative keyword names or as shorthand for frequently used keyword constructions and logical expressions. A symbol can be defined at any ARCQUERY prompt. For example, define at the ARCQUERY prompt the symbol ABC:


Then, the subsequent instruction:

ABC OBJECT=N*4151* is equivalent to: SELECT/NOLIST/FILE OBJECT=N*4151*

At any ARQUERY prompt a symbol may be given as answer, if it makes sense, that is. If a symbol is used as a value of a keyword it must be entered between apostrophes (DCL fashion).

The use of symbols can greatly simplify complex ARCQUERY command structures, because many symbols can occur in the same line. In section some examples are presented in more detail. However, it should be kept in mind that the ARCQUERY command parser simply substitutes the symbol value at the position where it occurs in a string. Thus, the syntax of the command, after substitution, must obey the syntax rules given in section . Further, the length of the command after substitution cannot exceed 512 characters.

Symbols may be preceded by NO to negate their values. Symbol names cannot be abbreviated, unless the symbol was defined with the VAX/VMS wildcard () in its name (DCL fashion), e.g. after AB*C = ... , AB will have the same effect or value as ABC. Note, however, that a symbol name will always first be tried as an (abbreviated) keyword name; thus, a symbol name identical to a keyword name is useless.

On the captive account, symbols may also be predefined in the User Initialization File (see section ).

Fri Aug 12 10:24:53 BST 1994