rem: vcal = Parse_MIME_FromFileName(argv[1]);
add: if (argc != 2){ file = "../../test-data/user-cal.vcf"; } else { file = argv[1]; }   vcal = Parse_MIME_FromFileName(file);
context: int main(int argc, char* argv[]){    VObject *vcal = 0;    icalcomponent *comp;    vcal = Parse_MIME_FromFileName(argv[1]);        assert(vcal != 0);    comp = icalvcal_convert(vcal);    printf("%s\n",icalcomponent_as_ical_string(comp));        return 0;}           