IO::Buffer#readonly?

readonly? → true or false

static VALUE
io_buffer_readonly_p(VALUE self)
{
    return RBOOL(rb_io_buffer_readonly_p(self));
}

If the buffer is read only, meaning the buffer cannot be modified using set_value, set_string or copy and similar.

Frozen strings and read-only files create read-only buffers.

See also #read #resize #pwrite #set_string also in 4.1 · 4.0 · 3.4 · 3.2 · 3.1