WsDFU/DFUInfo should report ECL record definition. The DFUInfo response seems purposely omit the ECL record definition for non-FLAT files.
Providing sample DFUInfo responce for accounts file created as FLAT, and as CSV via ECL output statement.
Note that the flat version contains ECL record definition, while the other one does not:
FLAT Version:
<DFUInfoResponse><FileDetail><Name>progguide::exampledata::accounts</Name>
...
<Modified>2012-02-15 16:21:07</Modified><Ecl>RECORD
unsigned3 personid;
qstring20 account;
...
unsigned4 highcredit;
unsigned4 balance;
END;
</Ecl>
...
</FileDetail></DFUInfoResponse>
CSV Version:
<DFUInfoResponse><FileDetail><Name>progguide::exampledata::accounts.csv</Name>
...
<RecordCount>5,000,000</RecordCount><Wuid>W20130906-150843</Wuid><Format>utf8n</Format>
<MaxRecordSize/>
<CsvSeparate/>
<CsvQuote/>
<CsvTerminate/>
<Ecl/>
<ZipFile>0</ZipFile>
...
</FileDetail></DFUInfoResponse>