Goal: execute a program via a command line from groovy code
Option 1: executing a string
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A string can be executed in the standard java way:
def command = """executable arg1 arg2 arg3"""// Create the String
def proc = command.execute() // Call *execute* on the string
proc.waitFor() // Wait for the command to finish
// Obtain status and output
println "return code: ${ proc.exitValue()}"
println "stderr: ${proc.err.text}"
println "stdout: ${proc.in.text}" // *out* from the external program is *in* for groovy
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Gotchas: Take care if you wish to pass a quoted argument that contains white space – it will be split into multiple arguments, e.g.:
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"""executable "first with space" second""".execute() |
will invoke executable with the following arguments:
- arg1 = "first
- arg2 = with
- arg3 = space"
- arg4 = second
In such a case, you may prefer to use one of the array or list of String variations, e.g.:
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["executable", "first with space", "second"].execute() |
Option 2: using ant builder's exec task
Ant has an exec task and it be accessed from the AntBuilder object
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def ant = new AntBuilder() // create an antbuilder
ant.exec(outputproperty:"cmdOut",
errorproperty: "cmdErr",
resultproperty:"cmdExit",
failonerror: "true",
executable: /opt/myExecutable') {
arg(line:"""*"first with space"* second""")
}
println "return code: ${ant.project.properties.cmdExit}"
println "stderr: ${ant.project.properties.cmdErr}"
println "stdout: ${ ant.project.properties.cmdOut}"
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The good thing is that you now have all the ant features at your disposal and Ant will not break up quoted args containing whitespace.
See also: Process Management