bitpim-devel

[Bitpim-devel] Strings in packet description

[Stephen W. <sa...@us...>]

I have the following packet description:

PACKET {'readwrite': 0x0d} sanyoheader:
    1 UINT readwrite
    1 UINT command
    1 UINT packettype

PACKET phonebookentry:
    2 UINT slot
    2 UINT slotdup
    16 STRING name
    * LIST {'length': 7} numbers:
        1 UINT number_len
        49 STRING number
    1 UINT email_len
    49 STRING email
    1 UINT url_len
    49 STRING url
    1 UINT secret
    1 UINT name_len
     
PACKET phonebookslotresponse:
    * sanyoheader header
    * phonebookentry entry
    30 UNKNOWN pad

When I try to read a packet with names less than 16 characters, it works
(the phone pads fields with nulls).  But on the following packet, with a
16 character name, I get an error.  Are there some attributes to STRING
that I can add that will help?  The length of the string is available in
the packet, but is not located adjacent to the string itself.

			Steve

Re: [Bitpim-devel] Strings in packet description

[Roger B. <ro...@ro...>]

> When I try to read a packet with names less than 16 characters, it works
> (the phone pads fields with nulls).  But on the following packet, with a
> 16 character name, I get an error.  

You can set raiseonunterminatedread to False.

> Are there some attributes to STRING
> that I can add that will help?  The length of the string is available in
> the packet, but is not located adjacent to the string itself.

I guess the problem here is that the field has a length in bytes
(including padding) as well as a length in characters.  It even 
looks like the length in characters can be in a later field
which makes things even nastier.

If the raiseonunterminatedread doesn't work for you, you could derive
a new string class (or add an argument to the existing one) that
lets you truncate the characters to a certain size.  It won't be
much use when the length field is after the string field though.

Roger