Input to an SgmlQL query can come from a file, using the operator file. The filename is given by string. File input can be used in either interactive or non-interactive mode. The format can then be specified by giving to name one of the values NSGML or SGMLS. If the format is not specified, it is detected automatically from the input.
The empty option can be used to specify the generic identifiers of the nodes which must be read as SGML EMPTY TAGS.
Prototype
document <-- file string [ format: name ] [ empty: names ]
Example
global $afile = file "myfile-ces.sgml" empty: {PTR,IMG};If string starts with the pipe sign (i.e. "| string") the input is the output of the UN*X command contained in the following string.
Example
top DATE within file "| nsgmls myfile-ces.sgml" ;