org.cdlib.xtf.saxonExt.exec
Class RunInstruction

Object
  Expression
      SimpleExpression
          RunInstruction

All Implemented Interfaces:

Serializable, SourceLocator, Container, EvaluableItem, SequenceIterable, InstructionInfoProvider

Direct Known Subclasses:

PipeImageInstruction

 class RunInstruction
extends SimpleExpression

Utility class that does most of the work for RunElement.

Field Summary

protected Expression	command
protected InputElement.InputInstruction	inputExpr
protected int	nArgs
protected int	timeout

Fields inherited from class SimpleExpression

arguments, NO_ARGUMENTS

Fields inherited from class Expression

EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties

Constructor Summary

RunInstruction(Expression command, int timeout, List args)

Method Summary

Item	evaluateItem(XPathContext context)
protected String[]	gatherArgs(XPathContext context) Gather all the arguments for this instruction and make them into a convenient array.
String	getExpressionType()
int	getImplementationMethod() A subclass must provide one of the methods evaluateItem(), iterate(), or process().
protected byte[]	runAndGrab(XPathContext context, String[] argArray) Run the external process, applying a timeout if specified, feeding it input on stdin and gathering the results from stdout.

Methods inherited from class SimpleExpression

computeCardinality, computeDependencies, display, getItemType, iterate, iterateSubExpressions, optimize, process, promote, replaceSubExpression, setArguments, simplify, typeCheck

Methods inherited from class Expression

adoptChildExpression, checkPermittedContents, computeSpecialProperties, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getContainingProcedure, getDependencies, getExecutable, getHostLanguage, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

command

protected Expression command

timeout

protected int timeout

nArgs

protected int nArgs

inputExpr

protected InputElement.InputInstruction inputExpr

Constructor Detail

RunInstruction

public RunInstruction(Expression command,
                      int timeout,
                      List args)

Method Detail

getImplementationMethod

public int getImplementationMethod()

A subclass must provide one of the methods evaluateItem(), iterate(), or process(). This method indicates which of the three is provided.

Overrides:

getImplementationMethod in class Expression

getExpressionType

public String getExpressionType()

Overrides:

getExpressionType in class SimpleExpression

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Specified by:

evaluateItem in interface EvaluableItem

Overrides:

evaluateItem in class SimpleExpression

Throws:

XPathException

runAndGrab

protected byte[] runAndGrab(XPathContext context,
                            String[] argArray)
                     throws XPathException,
                            DynamicError

Run the external process, applying a timeout if specified, feeding it input on stdin and gathering the results from stdout. If a non-zero exit status is returned, we throw an exception containing the output string from stderr.

Throws:

XPathException

DynamicError

gatherArgs

protected String[] gatherArgs(XPathContext context)
                       throws XPathException

Gather all the arguments for this instruction and make them into a convenient array.

Throws:

XPathException