Executing shell command in groovy throws 'unexpected char' error

Question

I am trying to execute a shell command n groovy

def shellString = "s/\[\|]\|\s\|'\|(\|)//g"
def temp2 = "echo response| sed -e ${shellString}".execute()

It throws compilation error:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
WorkflowScript: 33: unexpected char: '\' @ line 33, column 24.
     def shellString = "s/\[\|]\|\s\|'\|(\|)//g"
                          ^

1 error

    at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:310)
    at org.codehaus.groovy.control.ErrorCollector.addFatalError(ErrorCollector.java:150)
    at org.codehaus.groovy.control.ErrorCollector.addError(ErrorCollector.java:120)
    at org.codehaus.groovy.control.ErrorCollector.addError(ErrorCollector.java:132)
    at org.codehaus.groovy.control.SourceUnit.addError(SourceUnit.java:350)
    at org.codehaus.groovy.antlr.AntlrParserPlugin.transformCSTIntoAST(AntlrParserPlugin.java:139)
    at org.codehaus.groovy.antlr.AntlrParserPlugin.parseCST(AntlrParserPlugin.java:110)
    at org.codehaus.groovy.control.SourceUnit.parse(SourceUnit.java:234)
    at org.codehaus.groovy.control.CompilationUnit$1.call(CompilationUnit.java:168)
    at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:943)
    at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:605)
    at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:581)
    at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:558)
    at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:298)
    at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:268)
    at groovy.lang.GroovyShell.parseClass(GroovyShell.java:688)
    at groovy.lang.GroovyShell.parse(GroovyShell.java:700)
    at org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.doParse(CpsGroovyShell.java:131)
    at org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.reparse(CpsGroovyShell.java:125)
    at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.parseScript(CpsFlowExecution.java:560)
    at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.start(CpsFlowExecution.java:521)
    at org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:330)
    at hudson.model.ResourceController.execute(ResourceController.java:97)
    at hudson.model.Executor.run(Executor.java:429)

shellString isn't a slashed string, so not sure why a \ would create a problem. Any help is appreciated.

Answer 1

You need to escape slash to avoid compilation errors:

def shellString = "s/\\[\\|]\\|\\s\\|'\\|(\\|)//g"
def temp2 = "echo response| sed -e ${shellString}".execute()

println temp2.text

Output:

response| sed -e s/\[\|]\|\s\|'\|(\|)//g

Answer 2

This will fail on many levels. The biggest problem you will face is the fact, that execute is really just executing a process (not a shell command). So first of all you can not use | at all. Next quoting arguments will not work, because execute will just split at whitespace. So if you want to use "shellisms" use the equivalent of sh -c "..." instead and use execute on a string array. E.g.

["sh", "-c", "..."].execute()

Then you can put your ... shell code in there with all the redirections, quotings, env-vars etc. with the proper Groovy quoting applied as mentioned in the other answer.

And to circumvent all of that: why even bother with sed here? Just use replaceAll on the resulting string on the groovy side of things.