Method: StringIO#ungetbyte

Defined in:
ext/stringio/stringio.c

#ungetbyte(byte) ⇒ nil

Pushes back (“unshifts”) an 8-bit byte onto the stream; see Byte IO.

Returns:

  • (nil) 


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# File 'ext/stringio/stringio.c', line 967

static VALUE
strio_ungetbyte(VALUE self, VALUE c)
{
    struct StringIO *ptr = readable(self);

    check_modifiable(ptr);
    if (NIL_P(c)) return Qnil;
    if (RB_INTEGER_TYPE_P(c)) {
        /* rb_int_and() not visible from exts */
        VALUE v = rb_funcall(c, '&', 1, INT2FIX(0xff));
        const char cc = NUM2INT(v) & 0xFF;
        strio_unget_bytes(ptr, &cc, 1);
    }
    else {
	long cl;
	SafeStringValue(c);
	cl = RSTRING_LEN(c);
	if (cl > 0) {
	    strio_unget_bytes(ptr, RSTRING_PTR(c), cl);
	    RB_GC_GUARD(c);
	}
    }
    return Qnil;
}