A ruby script that will parse GrADs control files and generate NCL code to generate netcdf objects of the variables in the 'ctl' file. You would need to run the generated NCL code and add additional code to write out the netcdf file (left to the user)

Usage: ctl2ncl.rb [options]
A grads ctl parser and NCL code generator based on ruby
Specific options:
    -i, --infile CTLFILE             the grads ctl file 
    -o, --outfile NCLFILE            the NCL script file 
    -v, --vars *NUM                  variables to retrieve
                                     e.g: --vars u850 t850 prec
                                     or -v u850 t850 prec
    -t, --time time(s)               -t : supply time as indices
                                     e.g -t 1:5 retrieves data
                                     from t=1 to 5

                                     --time : supply calendar time
                                     e.g --time Jan2005:Dec2005
                                     retrieves data from 
                                     time =Jan2005 to Dec2005
        --plot                       add code to display figures

Common options: 
        --help                       Show this message
        --version                    Show version