rb_econv_open     223 include/ruby/encoding.h rb_econv_t *rb_econv_open(const char *source_encoding, const char *destination_encoding, int ecflags);
rb_econv_open    1476 transcode.c        ec = rb_econv_open(sname, dname, 0);
rb_econv_open    2369 transcode.c        ec = rb_econv_open(source_encoding, destination_encoding, ecflags);