The decc$feature_show function displays to stdout all values for
    the specified feature name. For example:

    --------- C RTL Feature Name ---------   Cur  Def  Min  Max  Ini

    DECC$V62_RECORD_GENERATION                0    0    0    1    -1

    On error, -1 is returned and errno is set to indicate the error.

    See also decc$feature_get, decc$feature_get_index, decc$feature_
    get_name, decc$feature_get_value, decc$feature_set, decc$feature_
    set_value, and decc$feature_show_all.