Eval Documentation
Eval is a command line utility to evaluate XPath 2.0 expression.
Eval is executed as follows:
Usage: eval [options] "XPath Expression" [ data1.xml ... ]
-f : Enable XPath 1.0 compatibility mode (default is off)
-h : Show this display
-i inputfile : append the child nodes in inputfile to input()
-I inputfile : append the document root of inputfile to input()
-e : Enable schema error reporting
-d : Enable debug
-x : Enable full exception debugging (all exception throws shown)
-N prefix uri : bind prefix to the namespace uri
For example:
eval "avg(//Price)" test.xml
ie. Retrieve the average price of books in the following file:
<?xml version="1.0" encoding="utf-8"?>
<Catalogue>
<Book>
<ISBN>1234</ISBN>
<Price>14.99</Price>
</Book>
<Book>
<ISBN>1235</ISBN>
<Price>89.99</Price>
</Book>
<Book>
<ISBN>1237</ISBN>
<Price>14.999</Price>
</Book>
</Catalogue>
will produce the result
39.99
and the following line, where we bind the 'xdt' prefix to the XPath 2.0 datatypes URI:
eval 'xs:float("3.56") + xdt:untypedAtomic("17.3") cast as xs:decimal' -N xdt http://www.w3.org/2003/05/xpath-datatypes
doesn't take an xml file, and evaluates the sum of an xs:float and an xdt:untypedAtomic, and then casts the result to an xs:decimal.
The output given is:
20.86
There are many functional tests in the functionalTesting/ directory. To run them all, run the program
'./runTests.sh' from that directory. Alternatively, you can
choose to run tests in a particular directory by calling './tester {path to directory}'.
While this is designed to be run under UNIX systems, the shell scripts provide example invocations of eval which can be used on Windows systems.
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