1) : directly execute a string statement, executing a string

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

Gotchas:Take care if you wish to pass a quoted argument that contains white space– it will be split into multiple arguments, e.g.:

"""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 useone of the array or list of String variations, e.g.:

["executable", "first with space", "second"].execute()

2)Processing shell command with piping in groovy script, Using pipeline functions in groovy scripts

def proc = “ffmpeg -i /tmp/sample.m4a -f ffmetadata 2>&1 | grep Duration”.execute()

is not working.the ‘2>1&1’ bit is shell functionality, and Groovy processes don’t invoke the shell, they just start a program. If you really need it, you should do something like:

def proc1 = [‘/bin/bash’, ‘-c’, ‘/usr/local/bin/ffmpeg -i /tmp/sample.m4a -fffmetadata 2>&1’].execute()

or similar – do some experimenting. That is, you need to call the shell with the command you want executed as argument.

3): using ant builder’s exec task

Ant has an exec task and it be accessed from the AntBuilder object

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}"