End of Life Ruby 3.2 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

FileTest#setgid?

File.setgid?(file_name) → true or false

static VALUE
rb_file_sgid_p(VALUE obj, VALUE fname)
{
#ifdef S_ISGID
    return check3rdbyte(fname, S_ISGID);
#else
    return Qfalse;
#endif
}

Returns true if the named file has the setgid bit set.

file_name can be an IO object.

See also #readable_real? #setuid? #readable? #size also in 4.1 · 4.0 · 3.4 · 3.3 · 3.1 · 3.0