putback

call-seq

ec.putback                    -> string
ec.putback(max_numbytes)      -> string

Put back the bytes which will be converted.

The bytes are caused by invalid_byte_sequence error. When invalid_byte_sequence error, some bytes are discarded and some bytes are buffered to be converted later. The latter bytes can be put back. It can be observed by Encoding::InvalidByteSequenceError#readagain_bytes and Encoding::Converter#primitive_errinfo.

ec = Encoding::Converter.new("utf-16le", "iso-8859-1")
src = "\x00\xd8\x61\x00"
dst = ""
p ec.primitive_convert(src, dst)   #=> :invalid_byte_sequence
p ec.primitive_errinfo     #=> [:invalid_byte_sequence, "UTF-16LE", "UTF-8", "\x00\xD8", "a\x00"]
p ec.putback               #=> "a\x00"
p ec.putback               #=> ""          # no more bytes to put back