[galaxy-dev] How can I get a txt output file from R

Code:________________________________________________________________<tool id="predictionModelTool" name="Modelo de Deteccao de Risco">...<command interpreter="bash">r_wrapper.sh $script_file</command><inputs>... </inputs> <configfiles> <configfile name="script_file"> ... file=file("output.txt","w") source("/home/ramao/Galaxy-ES/tools/my_tools/modeloCancroEuropeu.R") close(file) ... </configfile> </configfiles> <outputs><data format="txt" name="output.txt"/></outputs> ... </tool>________________________________________________________________ I'm having the output "empty" and I need that the result be generated in a text file. What can I do? Thank you