import traceback
import sys

from gribapi import *

VERBOSE=1 # verbose error reporting

def example():
    f = open(sys.argv[1])
    out = open(sys.argv[2],'w')

    while 1:
        gid = grib_new_from_file(f)
        if gid is None: break

        message = grib_get_message(gid)

        newgid = grib_new_from_message(message)
        grib_write(newgid,out)
        grib_release(newgid)

        grib_release(gid)

    out.close()
    f.close()

def main():
    try:
        example()
    except GribInternalError,err:
        if VERBOSE:
            traceback.print_exc(file=sys.stderr)
        else:
            print >>sys.stderr,err.msg

        return 1

if __name__ == "__main__":
    sys.exit(main())