This field is used to specify the way in which a value is obtained for a parameter if the user does not specify a value (on the command line, or by an ICL SEND SET command, for example) before it is required by the program. In that case, there are several potential sources for parameter values and different applications will want to use different sources for their various parameters.
The VPATH field is the means whereby this order of searching for parameter values is specified.
The field is of the form:
where value-resolution-path is a character string which gives a path used for searching for a parameter value. It consists of a set of path specifiers. If there are two or more path specifiers, they must be separated by commas and the string must be enclosed in single quotes.VPATH value-resolution-path
The valid specifiers are:
If the value for a parameter has not been specified when it is required, the system looks at the VPATH specification, picks out the first path specifier and tries to find a value from this source. If a value is not found, the next path specifier is extracted and another search is made. This process continues until a value is found, the specifier is NOPROMPT or the path specification runs out. If the path specification is exhausted, the user is prompted for a value.
Note that the VPATH field is only used the first time a parameter value is obtained. If the parameter is cancelled before another attempt to `get' a value, a prompt will be issued, even if NOPROMPT is put on the VPATH. If the parameter is not cancelled, the existing value will be returned again.
If the VPATH field is omitted, VPATH PROMPT is assumed.
ADAM Interface Module Reference Manual