Fix whitespace padding for PWR

krasoffski commented 5 months ago

In some cases WSPR does not decode signal power less than 10. wsprd_utils.c has simple coverter from decimal to string sprintf(cdbm, "%2d", ndbm);. This works without issue for values bigger than 10. On the other side, some station transmit with values less than 10 or oven with 0 dBm power.

Than we use this value like 0 (whitespace with zero) to build request url using %s formatting. As a result, url contains invalid value like &dbm= 0 and curl cannot perform this request.

Here is simplifies error log.

              Date   Time    SNR     DT       Freq Dr    Call    Loc Pwr
Spot :  2024-02-29 15:14z -14.54  -0.78  14.097040  0  DB1IAT   JN48 00
Decoder thread -- Sending spot using this URL: http://wsprnet.org/post?function=wspr&rcall=SP2RM&rgrid=JO94hj&rqrg=14.097038&date=240229&time=1356&sig=-20&dt=-0.6&tqrg=14.097038&tcall=DB1IAT&tgrid=JN48&dbm= 0&version=rtlsdr-054&mode=2
curl_easy_perform() failed: URL using bad/illegal format or missing URL

I checked that wsprnet.org respets values like &dbm=01 or &dbm=00 without issues, thus I added zero padding.

> curl -X POST 'http://wsprnet.org/post?function=wspr&rcall=EW1IM&rgrid=JO94hj&rqrg=14.097038&date=240229&time=1354&sig=-20&dt=-0.6&tqrg=14.097038&tcall=DB1IAT&tgrid=JN48&dbm=%200&version=rtlsdr-054&mode=2'
<html>

<body>
  1 out of 1 spot(s) added<br>
Processing took 107 milliseconds.<br>
</body>

The second solution is to escape this particular PWR value using curl_easy_escape before formatting (building) url.

krasoffski commented 5 months ago

Here is example from wsprnet.org with this fix.

Guenael commented 5 months ago

Hi Yuri, Thanks for the bug fix, appreciated! Merged, but I have to fix my pipeline and push a new release. 73, Guenael

Guenael / rtlsdr-wsprd

Fix whitespace padding for PWR #136