How do I execute shell script from Jenkins groovy script in the parameters option?

[Shubham Sharma]

I want to call a shell script in the Uno-Choice Dynamic Reference Parameter and perform some operation (create some files and call some other shell scripts from the called shell script) .

As of now I am able to call shell script and cat some files but I am not able to create new files or call another shell script from within this.

def sout = new StringBuffer(), serr = new StringBuffer()

// 1) 
def proc ='cat /home/path/to/file'.execute()
//display contents of file

// 2) 
def proc="sh /home/path/to/shell/script.sh".execute()
//to call a shell script but the above dosent work if I echo some contents
//into some file.

proc.consumeProcessOutput(sout, serr)
proc.waitForOrKill(1000)
return sout.tokenize()

eg:- in script.sh if I add line

echo "hello world" > test
then test file is not created but instead if I do 
echo "hello world" 
It gets printed on the Jenkins console
for more understanding:
http://stackoverflow.com/questions/30253684/how-do-i-execute-shell-script-from-jenkins-groovy-script-in-the-parameters-optio?noredirect=1#comment48608118_30253684
Please help.

Regards
Shubham